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Langfuse Cloud MCP
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Langfuse Cloud MCP
Authenticated project-scoped MCP server for Langfuse Cloud projects.
https://cloud.langfuse.com/api/public/mcpAPI stability
This MCP server is self-describing. Clients should dynamically inspect available tools and schemas rather than assuming a static interface.
Tool availability and schemas may evolve over time, including the addition, removal, or modification of tools and fields. Clients are expected to tolerate schema changes and refresh capabilities dynamically.
Cloud EU
https://cloud.langfuse.com/api/public/mcp
Cloud US
https://us.cloud.langfuse.com/api/public/mcp
Cloud Japan
https://jp.cloud.langfuse.com/api/public/mcp
HIPAA US
https://hipaa.cloud.langfuse.com/api/public/mcp
Self-Hosted
https://your-domain.com/api/public/mcp
Local Development
http://localhost:3000/api/public/mcp
Client setup
Cursor mcp.json
json
{
"mcpServers": {
"langfuse-cloud": {
"url": "https://cloud.langfuse.com/api/public/mcp",
"headers": {
"Authorization": "Basic <base64(LANGFUSE_PUBLIC_KEY:LANGFUSE_SECRET_KEY)>"
}
}
}
}Tools
getPrompt
Fetch a specific prompt by name with optional label or version parameter. Retrieval options: - label: Get prompt with specific label (e.g., 'production', 'staging') - version: Get specific version number (e.g., 1, 2, 3) - neither: Returns 'latest' version by default Note: label and version are mutually exclusive. Returns full prompt content with resolved dependencies.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"name": {
"type": "string",
"minLength": 1,
"maxLength": 255,
"description": "The name of the prompt"
},
"label": {
"description": "Label to retrieve (e.g., \"production\", \"staging\"). Defaults to \"latest\".",
"type": "string",
"minLength": 1,
"maxLength": 36,
"pattern": "^[a-z0-9_\\-.]+$"
},
"version": {
"description": "Specific version number to retrieve (e.g., 1, 2, 3)",
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
}
},
"required": [
"name"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getPrompt",
"arguments": {
"name": "string",
"label": "string",
"version": 1
}
}
}getPromptUnresolved
Fetch a specific prompt by name with optional label or version parameter WITHOUT resolving dependencies. Returns the raw prompt content with dependency tags intact. Useful for: - Understanding prompt composition/stacking before resolution - Debugging prompt dependencies - Analyzing the dependency graph structure Retrieval options: - label: Get prompt with specific label (e.g., 'production', 'staging') - version: Get specific version number (e.g., 1, 2, 3) - neither: Returns 'latest' version by default Note: label and version are mutually exclusive. To get resolved prompts, use the 'getPrompt' tool instead.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"name": {
"type": "string",
"minLength": 1,
"maxLength": 255,
"description": "The name of the prompt"
},
"label": {
"description": "Label to retrieve (e.g., \"production\", \"staging\"). Defaults to \"latest\".",
"type": "string",
"minLength": 1,
"maxLength": 36,
"pattern": "^[a-z0-9_\\-.]+$"
},
"version": {
"description": "Specific version number to retrieve (e.g., 1, 2, 3)",
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
}
},
"required": [
"name"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getPromptUnresolved",
"arguments": {
"name": "string",
"label": "string",
"version": 1
}
}
}listPrompts
List and filter prompts in the project. Returns metadata including versions, labels, tags, last updated timestamp, and prompt type. Optional filters: - name: Filter by exact prompt name - label: Filter by label on any version - tag: Filter by tag - fromUpdatedAt: Filter prompts updated at or after this timestamp - toUpdatedAt: Filter prompts updated at or before this timestamp Pagination: page (default: 1), limit (default: 50, max: 100)
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"name": {
"description": "Filter by exact prompt name match",
"type": "string",
"minLength": 1,
"maxLength": 255
},
"label": {
"description": "Filter by label (e.g., 'production', 'staging')",
"type": "string",
"minLength": 1,
"maxLength": 36,
"pattern": "^[a-z0-9_\\-.]+$"
},
"tag": {
"description": "Filter by tag (e.g., 'experimental', 'v1')",
"type": "string"
},
"fromUpdatedAt": {
"description": "Filter prompts updated at or after this timestamp (ISO 8601 with timezone, e.g. 2026-02-02T00:00:00Z)",
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
},
"toUpdatedAt": {
"description": "Filter prompts updated at or before this timestamp (ISO 8601 with timezone, e.g. 2026-02-02T00:00:00Z)",
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
},
"page": {
"default": 1,
"description": "Page number for pagination (default: 1)",
"type": "integer",
"minimum": 1,
"maximum": 9007199254740991
},
"limit": {
"default": 50,
"description": "Number of items to return (1-100, default: 50)",
"type": "integer",
"minimum": 1,
"maximum": 100
}
},
"required": [
"page",
"limit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listPrompts",
"arguments": {
"limit": 50,
"page": 1,
"fromUpdatedAt": "2026-05-15T12:00:00.000Z",
"label": "string",
"name": "string",
"tag": "string",
"toUpdatedAt": "2026-05-15T12:00:00.000Z"
}
}
}createTextPrompt
Create a new text prompt version in Langfuse. Important: - Prompts are immutable - cannot modify existing versions - To update content, create a new version - New prompt versions receive the 'latest' label automatically - Cannot assign the 'production' label during creation - To promote to production, use updatePromptLabels only when the user explicitly requests it - Labels are unique across versions - Use {{variable_name}} syntax for dynamic content Accepts: name, prompt (string), optional labels, config, tags, commitMessage
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"name": {
"type": "string",
"minLength": 1,
"maxLength": 255,
"description": "The name of the prompt"
},
"prompt": {
"type": "string",
"description": "The prompt text content (supports {{variables}})"
},
"labels": {
"description": "Optional labels to assign, excluding 'production'. New prompt versions receive the 'latest' label automatically.",
"type": "array",
"items": {
"type": "string"
}
},
"config": {
"description": "Optional JSON config (e.g., {model: 'gpt-4', temperature: 0.7})",
"type": "object",
"propertyNames": {
"type": "string"
},
"additionalProperties": {}
},
"tags": {
"description": "Optional tags for organization (e.g., ['experimental', 'v2'])",
"type": "array",
"items": {
"type": "string"
}
},
"commitMessage": {
"description": "Optional commit message describing the changes",
"type": "string"
}
},
"required": [
"name",
"prompt"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "createTextPrompt",
"arguments": {
"name": "string",
"prompt": "string",
"commitMessage": "string",
"config": {
"property": {}
},
"labels": [
"string"
],
"tags": [
"string"
]
}
}
}createChatPrompt
Create a new chat prompt version in Langfuse. Chat prompts are arrays of messages with roles and content. Important: - Prompts are immutable - cannot modify existing versions - To update content, create a new version - New prompt versions receive the 'latest' label automatically - Cannot assign the 'production' label during creation - To promote to production, use updatePromptLabels only when the user explicitly requests it - Labels are unique across versions Message roles: system (instructions), user (input, can contain {{variables}}), assistant (examples) Placeholder messages: {type: 'placeholder', name: '<variable>'} reference runtime variable values (e.g. conversation history) inserted when the prompt is used Accepts: name, prompt (array of {role, content} or {type: 'placeholder', name}), optional labels, config, tags, commitMessage
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"name": {
"type": "string",
"minLength": 1,
"maxLength": 255,
"description": "The name of the prompt"
},
"prompt": {
"minItems": 1,
"type": "array",
"items": {
"type": "object",
"properties": {
"type": {
"description": "Message type. Defaults to 'message'. Use 'placeholder' to reference a runtime variable value (e.g. conversation history) instead of a literal message.",
"type": "string",
"enum": [
"message",
"placeholder"
]
},
"role": {
"description": "The role (e.g., 'system', 'user', 'assistant'). Required for 'message' type.",
"type": "string"
},
"content": {
"description": "The message content. Required for 'message' type.",
"type": "string"
},
"name": {
"description": "The variable name for 'placeholder' type messages (e.g. 'history'). Required for 'placeholder' type.",
"type": "string"
}
},
"additionalProperties": false
},
"description": "Array of chat messages. Each message is either {role, content} or a placeholder {type: 'placeholder', name: '<variable>'} that is replaced with a runtime variable value"
},
"labels": {
"description": "Optional labels to assign, excluding 'production'. New prompt versions receive the 'latest' label automatically.",
"type": "array",
"items": {
"type": "string"
}
},
"config": {
"description": "Optional JSON config (e.g., {model: 'gpt-4', temperature: 0.7})",
"type": "object",
"propertyNames": {
"type": "string"
},
"additionalProperties": {}
},
"tags": {
"description": "Optional tags for organization (e.g., ['experimental', 'v2'])",
"type": "array",
"items": {
"type": "string"
}
},
"commitMessage": {
"description": "Optional commit message describing the changes",
"type": "string"
}
},
"required": [
"name",
"prompt"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "createChatPrompt",
"arguments": {
"name": "string",
"prompt": [
{
"content": "string",
"name": "string",
"role": "string",
"type": "message"
}
],
"commitMessage": "string",
"config": {
"property": {}
},
"labels": [
"string"
],
"tags": [
"string"
]
}
}
}updatePromptLabels
Update labels for a specific prompt version. Important: - ONLY way to modify existing prompts (labels only) - Specified labels are added to the version (preserving others not mentioned) - Labels are unique across versions - setting a label on one version automatically removes it from others - 'latest' label is auto-managed and cannot be set manually - Only add the 'production' label when the user explicitly asks to promote this prompt version to production - Cannot modify prompt content, type, or tags - use createTextPrompt or createChatPrompt for new versions Accepts: name, version (required), newLabels (array, can be empty to remove all labels)
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"name": {
"type": "string",
"minLength": 1,
"maxLength": 255,
"description": "The name of the prompt"
},
"version": {
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991,
"description": "The version number to update (required)"
},
"newLabels": {
"type": "array",
"items": {
"type": "string"
},
"description": "Array of new labels to assign to the prompt version (can be empty to remove all labels). The 'latest' label is auto-managed and cannot be supplied."
}
},
"required": [
"name",
"version",
"newLabels"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "updatePromptLabels",
"arguments": {
"name": "string",
"newLabels": [
"string"
],
"version": 1
}
}
}listObservations
Requires v4Find and review observations in the current Langfuse project, such as generations, spans, events, agent steps, and tool calls. Traces consist of observations. Use this tool when the user asks to inspect traces: pass traceId to page through the observations for a specific trace; those observation records are the trace data returned by the API. Use filters to narrow results by trace, name, type, level, environment, time range, or advanced filter conditions. Results are paginated with an opaque cursor. For metadata filters, first inspect metadata on selectively scoped observations by passing traceId, an exact id filter, or both fromStartTime and toStartTime with fields: ["id", "metadata"]. Then use a discovered key in a stringObject filter. By default this returns compact summary fields. Use fields: ["*"] for the full observation, or pass specific field names to limit the response size. Important: if you request metadata explicitly, for example fields: ["id", "metadata"], metadata values are truncated to 200 UTF-8 characters per key unless you also pass expandMetadataKeys with the keys that may need full values. Requests that project or filter input, output, or metadata must include traceId, an id filter, or both fromStartTime and toStartTime.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"fields": {
"description": "Observation fields to include in the response. Omit for compact defaults, use [\"*\"] for all available fields, or pass specific field names to keep responses small. Call getObservationFieldSchema to list accepted fields.",
"type": "array",
"items": {
"type": "string"
}
},
"expandMetadataKeys": {
"description": "Metadata keys that may need full values. Metadata values are truncated to 200 UTF-8 characters per key by default when metadata is projected without this option.",
"type": "array",
"items": {
"type": "string"
}
},
"limit": {
"default": 50,
"description": "Number of observations to return (1-100, default: 50)",
"type": "integer",
"minimum": 1,
"maximum": 100
},
"cursor": {
"description": "Cursor returned by a previous listObservations call",
"type": "string"
},
"type": {
"type": "string",
"enum": [
"SPAN",
"EVENT",
"GENERATION",
"AGENT",
"TOOL",
"CHAIN",
"RETRIEVER",
"EVALUATOR",
"EMBEDDING",
"GUARDRAIL"
]
},
"name": {
"type": "string"
},
"userId": {
"type": "string"
},
"level": {
"type": "string",
"enum": [
"DEBUG",
"DEFAULT",
"WARNING",
"ERROR"
]
},
"traceId": {
"type": "string"
},
"version": {
"type": "string"
},
"parentObservationId": {
"description": "Physical parent observation ID to match exactly.",
"type": "string"
},
"isRootObservation": {
"description": "Filter by logical root status. App-root observations can match true while retaining a non-null parentObservationId.",
"type": "boolean"
},
"environment": {
"description": "Environment to filter by. Multiple environments are temporarily unsupported until the public observations API applies allow-multiple environment filters correctly.",
"type": "string"
},
"fromStartTime": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
},
"toStartTime": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
},
"filter": {
"description": "Advanced filters. Each item must be an object with column, operator, value, optional type, and optional key. Type is inferred from getObservationFilterSchema columns when omitted. Use key for metadata filters.",
"type": "array",
"items": {
"type": "object",
"properties": {
"column": {
"type": "string"
},
"operator": {
"type": "string"
},
"value": {},
"type": {
"type": "string"
},
"key": {
"description": "Metadata/object key to filter on. Required when column is metadata.",
"type": "string"
}
},
"required": [
"column",
"operator",
"value"
],
"additionalProperties": false,
"description": "Advanced observation filter object. Example: {\"column\":\"totalCost\",\"operator\":\">\",\"value\":0.0029}. The explicit form {\"type\":\"number\",\"column\":\"totalCost\",\"operator\":\">\",\"value\":0.0029} is also accepted."
}
}
},
"required": [
"limit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listObservations",
"arguments": {
"limit": 50,
"cursor": "string",
"environment": "string",
"expandMetadataKeys": [
"string"
],
"fields": [
"string"
],
"filter": [
{
"column": "string",
"operator": "string",
"value": {},
"key": "string",
"type": "string"
}
],
"fromStartTime": "2026-05-15T12:00:00.000Z",
"isRootObservation": true,
"level": "DEBUG",
"name": "string",
"parentObservationId": "string",
"toStartTime": "2026-05-15T12:00:00.000Z",
"traceId": "string",
"type": "SPAN",
"userId": "string",
"version": "string"
}
}
}getObservation
Requires v4Get the details for a single observation in the current Langfuse project by observation ID. Use this when you already know the observation ID and want to inspect its timing, model, status, payload, metadata, usage, cost, or prompt fields. By default this returns compact summary fields. Use fields: ["*"] for the full observation, or pass specific field names to limit the response size. Important: if you request metadata explicitly, for example fields: ["id", "metadata"], metadata values are truncated to 200 UTF-8 characters per key unless you also pass expandMetadataKeys with the keys that may need full values.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"observationId": {
"type": "string",
"minLength": 1
},
"fields": {
"description": "Observation fields to include in the response. Omit for compact defaults, use [\"*\"] for all available fields, or pass specific field names to keep responses small. Call getObservationFieldSchema to list accepted fields.",
"type": "array",
"items": {
"type": "string"
}
},
"expandMetadataKeys": {
"description": "Metadata keys that may need full values. Metadata values are truncated to 200 UTF-8 characters per key by default when metadata is projected without this option.",
"type": "array",
"items": {
"type": "string"
}
}
},
"required": [
"observationId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getObservation",
"arguments": {
"observationId": "string",
"expandMetadataKeys": [
"string"
],
"fields": [
"string"
]
}
}
}getObservationFieldSchema
Requires v4Show which observation fields can be requested from listObservations and getObservation. The response marks default fields and fields that may be large or contain sensitive application data.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {},
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getObservationFieldSchema",
"arguments": {}
}
}getObservationFilterSchema
Requires v4Show which observation fields can be used in listObservations filters, including the supported operators for each field.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {},
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getObservationFilterSchema",
"arguments": {}
}
}getObservationFilterValues
Requires v4List example values for a string or boolean observation filter field, such as names, types, levels, environments, model names, tags, users, or sessions. For numeric metric fields, returns a range with min, max, avg, and count. Use the returned cursor to page through long value lists.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"column": {
"type": "string",
"enum": [
"name",
"type",
"environment",
"version",
"userId",
"sessionId",
"traceName",
"level",
"promptName",
"promptVersion",
"modelId",
"providedModelName",
"totalCost",
"totalTokens",
"latency",
"timeToFirstToken",
"tags",
"isRootObservation",
"hasParentObservation"
]
},
"fromStartTime": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
},
"toStartTime": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
},
"observationType": {
"type": "string",
"enum": [
"SPAN",
"EVENT",
"GENERATION",
"AGENT",
"TOOL",
"CHAIN",
"RETRIEVER",
"EVALUATOR",
"EMBEDDING",
"GUARDRAIL"
]
},
"isRootObservation": {
"type": "boolean"
},
"hasParentObservation": {
"type": "boolean"
},
"limit": {
"default": 50,
"description": "Number of observations to return (1-100, default: 50)",
"type": "integer",
"minimum": 1,
"maximum": 100
},
"cursor": {
"type": "string"
}
},
"required": [
"column",
"limit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getObservationFilterValues",
"arguments": {
"column": "name",
"limit": 50,
"cursor": "string",
"fromStartTime": "2026-05-15T12:00:00.000Z",
"hasParentObservation": true,
"isRootObservation": true,
"observationType": "SPAN",
"toStartTime": "2026-05-15T12:00:00.000Z"
}
}
}listAnnotationQueues
List annotation queues, worklists that collect trace or observation items for human review and scoring, with pagination.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"page": {
"default": 1,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
},
"limit": {
"default": 50,
"type": "integer",
"minimum": 1,
"maximum": 100
}
},
"required": [
"page",
"limit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listAnnotationQueues",
"arguments": {
"limit": 50,
"page": 1
}
}
}createAnnotationQueue
Create an annotation queue, a worklist that collects trace or observation items for human review and scoring.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"name": {
"type": "string"
},
"description": {
"type": "string"
},
"scoreConfigIds": {
"minItems": 1,
"type": "array",
"items": {
"type": "string"
}
}
},
"required": [
"name",
"scoreConfigIds"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "createAnnotationQueue",
"arguments": {
"name": "string",
"scoreConfigIds": [
"string"
],
"description": "string"
}
}
}getAnnotationQueue
Get an annotation queue, a worklist of trace or observation items for human review and scoring, by ID.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"queueId": {
"type": "string"
}
},
"required": [
"queueId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getAnnotationQueue",
"arguments": {
"queueId": "string"
}
}
}listAnnotationQueueItems
List annotation queue items, each linking one trace or observation to a queue with a review status, with optional status filtering.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"page": {
"default": 1,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
},
"limit": {
"default": 50,
"type": "integer",
"minimum": 1,
"maximum": 100
},
"queueId": {
"type": "string"
},
"status": {
"type": "string",
"enum": [
"PENDING",
"COMPLETED"
]
}
},
"required": [
"page",
"limit",
"queueId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listAnnotationQueueItems",
"arguments": {
"limit": 50,
"page": 1,
"queueId": "string",
"status": "PENDING"
}
}
}getAnnotationQueueItem
Get an annotation queue item, one queued trace or observation with review status, by queue ID and item ID.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"queueId": {
"type": "string"
},
"itemId": {
"type": "string"
}
},
"required": [
"queueId",
"itemId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getAnnotationQueueItem",
"arguments": {
"itemId": "string",
"queueId": "string"
}
}
}createAnnotationQueueItem
Add an annotation queue item, one trace or observation to review, to a queue.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"queueId": {
"type": "string"
},
"objectId": {
"type": "string"
},
"objectType": {
"type": "string",
"enum": [
"TRACE",
"OBSERVATION",
"SESSION"
]
},
"status": {
"default": "PENDING",
"type": "string",
"enum": [
"PENDING",
"COMPLETED"
]
}
},
"required": [
"queueId",
"objectId",
"objectType",
"status"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "createAnnotationQueueItem",
"arguments": {
"objectId": "string",
"objectType": "TRACE",
"queueId": "string",
"status": "PENDING"
}
}
}updateAnnotationQueueItem
Update an annotation queue item's review status, such as pending or completed.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"queueId": {
"type": "string"
},
"itemId": {
"type": "string"
},
"status": {
"type": "string",
"enum": [
"PENDING",
"COMPLETED"
]
}
},
"required": [
"queueId",
"itemId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "updateAnnotationQueueItem",
"arguments": {
"itemId": "string",
"queueId": "string",
"status": "PENDING"
}
}
}deleteAnnotationQueueItem
Remove an annotation queue item, the queued trace or observation, from a queue.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"queueId": {
"type": "string"
},
"itemId": {
"type": "string"
}
},
"required": [
"queueId",
"itemId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "deleteAnnotationQueueItem",
"arguments": {
"itemId": "string",
"queueId": "string"
}
}
}createAnnotationQueueAssignment
Assign a project user to an annotation queue so they can work through its review items.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"queueId": {
"type": "string"
},
"userId": {
"type": "string"
}
},
"required": [
"queueId",
"userId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "createAnnotationQueueAssignment",
"arguments": {
"queueId": "string",
"userId": "string"
}
}
}deleteAnnotationQueueAssignment
Remove a project user's assignment from an annotation queue.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"queueId": {
"type": "string"
},
"userId": {
"type": "string"
}
},
"required": [
"queueId",
"userId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "deleteAnnotationQueueAssignment",
"arguments": {
"queueId": "string",
"userId": "string"
}
}
}createComment
Create a comment on a trace, observation, session, or prompt.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"content": {
"type": "string",
"minLength": 1,
"maxLength": 5000
},
"objectId": {
"type": "string"
},
"objectType": {
"type": "string",
"enum": [
"TRACE",
"OBSERVATION",
"SESSION",
"PROMPT"
]
},
"authorUserId": {
"type": "string"
}
},
"required": [
"content",
"objectId",
"objectType"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "createComment",
"arguments": {
"content": "string",
"objectId": "string",
"objectType": "TRACE",
"authorUserId": "string"
}
}
}listComments
List comments in the current Langfuse project, optionally filtered by object or author.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"objectType": {
"type": "string",
"enum": [
"TRACE",
"OBSERVATION",
"SESSION",
"PROMPT"
]
},
"objectId": {
"type": "string"
},
"authorUserId": {
"type": "string"
},
"page": {
"default": 1,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
},
"limit": {
"default": 50,
"type": "integer",
"minimum": 1,
"maximum": 100
}
},
"required": [
"page",
"limit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listComments",
"arguments": {
"limit": 50,
"page": 1,
"authorUserId": "string",
"objectId": "string",
"objectType": "TRACE"
}
}
}getComment
Get a comment by ID from the current Langfuse project.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"commentId": {
"type": "string"
}
},
"required": [
"commentId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getComment",
"arguments": {
"commentId": "string"
}
}
}upsertDataset
Upsert a dataset, a named collection of input and optional expected-output examples for experiments and evaluations.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"id": {
"type": "string",
"minLength": 1
},
"name": {
"type": "string"
},
"description": {
"type": "string"
},
"metadata": {},
"inputSchema": {},
"expectedOutputSchema": {}
},
"required": [
"name"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "upsertDataset",
"arguments": {
"name": "string",
"description": "string",
"expectedOutputSchema": {},
"id": "string",
"inputSchema": {},
"metadata": {}
}
}
}listDatasets
List datasets, named collections of input and optional expected-output examples for experiments and evaluations. Optionally filter by dataset name to find a dataset ID.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"name": {
"type": "string"
},
"page": {
"default": 1,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
},
"limit": {
"default": 50,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 100
}
},
"required": [
"page",
"limit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listDatasets",
"arguments": {
"limit": 50,
"page": 1,
"name": "string"
}
}
}getDataset
Get a dataset, a named collection of input and optional expected-output examples for experiments and evaluations, by ID.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"datasetId": {
"type": "string"
}
},
"required": [
"datasetId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getDataset",
"arguments": {
"datasetId": "string"
}
}
}upsertDatasetItem
Upsert a dataset item (one example in a dataset) by dataset ID. Item IDs are unique per project across all datasets, so an ID used in one dataset cannot be reused in another.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"datasetId": {
"type": "string"
},
"input": {},
"expectedOutput": {},
"metadata": {},
"id": {
"type": "string",
"minLength": 1,
"maxLength": 255
},
"sourceTraceId": {
"type": "string"
},
"sourceObservationId": {
"type": "string"
},
"status": {
"type": "string",
"enum": [
"ACTIVE",
"ARCHIVED"
]
}
},
"required": [
"datasetId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "upsertDatasetItem",
"arguments": {
"datasetId": "string",
"expectedOutput": {},
"id": "string",
"input": {},
"metadata": {},
"sourceObservationId": "string",
"sourceTraceId": "string",
"status": "ACTIVE"
}
}
}listDatasetItems
List dataset items, individual examples with input and optional expected output, optionally filtered by dataset ID, source trace, source observation, or version.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"datasetId": {
"type": "string"
},
"sourceTraceId": {
"type": "string"
},
"sourceObservationId": {
"type": "string"
},
"version": {
"type": "string"
},
"page": {
"default": 1,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
},
"limit": {
"default": 50,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 100
}
},
"required": [
"page",
"limit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listDatasetItems",
"arguments": {
"limit": 50,
"page": 1,
"datasetId": "string",
"sourceObservationId": "string",
"sourceTraceId": "string",
"version": "string"
}
}
}getDatasetItem
Get a dataset item, one example in a dataset with input and optional expected output, by ID.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"datasetItemId": {
"type": "string"
}
},
"required": [
"datasetItemId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getDatasetItem",
"arguments": {
"datasetItemId": "string"
}
}
}deleteDatasetItem
Delete a dataset item, one example in a dataset, and all its run items.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"datasetItemId": {
"type": "string"
}
},
"required": [
"datasetItemId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "deleteDatasetItem",
"arguments": {
"datasetItemId": "string"
}
}
}createDatasetRunItem
Create a dataset run item, a result that links one dataset item to a trace or observation in a dataset run.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"runName": {
"type": "string"
},
"runDescription": {
"type": "string"
},
"metadata": {},
"datasetItemId": {
"type": "string"
},
"observationId": {
"description": "Observation ID linked to this run item. Provide this or traceId.",
"type": "string"
},
"traceId": {
"description": "Trace ID linked to this run item. Provide this or observationId.",
"type": "string"
},
"datasetVersion": {
"type": "string"
},
"createdAt": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
}
},
"required": [
"runName",
"datasetItemId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "createDatasetRunItem",
"arguments": {
"datasetItemId": "string",
"runName": "string",
"createdAt": "2026-05-15T12:00:00.000Z",
"datasetVersion": "string",
"metadata": {},
"observationId": "string",
"runDescription": "string",
"traceId": "string"
}
}
}listDatasetRunItems
List dataset run items, each linking one dataset item to a trace or observation within a dataset run, by dataset ID and run ID.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"datasetId": {
"type": "string"
},
"datasetRunId": {
"type": "string"
},
"page": {
"default": 1,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
},
"limit": {
"default": 50,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 100
}
},
"required": [
"datasetId",
"datasetRunId",
"page",
"limit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listDatasetRunItems",
"arguments": {
"datasetId": "string",
"datasetRunId": "string",
"limit": 50,
"page": 1
}
}
}listDatasetRuns
List dataset runs, each experiment or evaluation execution over a dataset, by dataset ID.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"datasetId": {
"type": "string"
},
"page": {
"default": 1,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
},
"limit": {
"default": 50,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 100
}
},
"required": [
"datasetId",
"page",
"limit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listDatasetRuns",
"arguments": {
"datasetId": "string",
"limit": 50,
"page": 1
}
}
}getDatasetRun
Get a dataset run, one experiment or evaluation execution over a dataset, and its run items by dataset ID and run ID.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"datasetId": {
"type": "string"
},
"datasetRunId": {
"type": "string"
}
},
"required": [
"datasetId",
"datasetRunId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getDatasetRun",
"arguments": {
"datasetId": "string",
"datasetRunId": "string"
}
}
}deleteDatasetRun
Delete a dataset run by dataset ID and run ID, and enqueue deletion of its run items.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"datasetId": {
"type": "string"
},
"datasetRunId": {
"type": "string"
}
},
"required": [
"datasetId",
"datasetRunId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "deleteDatasetRun",
"arguments": {
"datasetId": "string",
"datasetRunId": "string"
}
}
}getHealth
Check Langfuse API health. Optionally verify database availability and recent trace/observation ingestion.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"failIfDatabaseUnavailable": {
"default": false,
"type": "boolean"
},
"failIfNoRecentEvents": {
"default": false,
"type": "boolean"
}
},
"required": [
"failIfDatabaseUnavailable",
"failIfNoRecentEvents"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getHealth",
"arguments": {
"failIfDatabaseUnavailable": false,
"failIfNoRecentEvents": false
}
}
}listScores
Find scores in Langfuse. Use this to review quality, evaluation, or feedback scores for traces, observations, sessions, and experiments (dataset runs). Each score carries a polymorphic value matching its dataType (number, boolean, or string) and a subject describing what it scores: { kind: trace | observation | session | experiment, id }. Results are paginated with an opaque cursor: pass meta.cursor from the previous response to fetch the next page; a response without meta.cursor is the last page. Filtering by trace user or trace tags is not supported. To find scores for a specific user, first resolve the user's trace IDs (e.g. via listObservations with userId), then filter scores by traceId. Score reads are eventually consistent: a score created with createScore may not appear in listScores immediately. If a newly created score is missing, wait briefly and retry.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"limit": {
"default": 50,
"type": "integer",
"minimum": 1,
"maximum": 100
},
"cursor": {
"type": "string"
},
"scoreIds": {
"type": "array",
"items": {
"type": "string"
}
},
"name": {
"type": "array",
"items": {
"type": "string"
}
},
"source": {
"type": "array",
"items": {
"type": "string",
"enum": [
"API",
"EVAL",
"ANNOTATION"
]
}
},
"dataType": {
"type": "array",
"items": {
"type": "string",
"enum": [
"NUMERIC",
"CATEGORICAL",
"BOOLEAN",
"CORRECTION",
"TEXT"
]
}
},
"environment": {
"type": "array",
"items": {
"type": "string"
}
},
"configId": {
"type": "array",
"items": {
"type": "string"
}
},
"queueId": {
"type": "array",
"items": {
"type": "string"
}
},
"authorUserId": {
"type": "array",
"items": {
"type": "string"
}
},
"value": {
"description": "string-encoded, requires a single dataType (NUMERIC, BOOLEAN, or CATEGORICAL)",
"type": "array",
"items": {
"type": "string"
}
},
"valueMin": {
"description": "inclusive, requires dataType: [\"NUMERIC\"]",
"type": "number"
},
"valueMax": {
"description": "inclusive, requires dataType: [\"NUMERIC\"]",
"type": "number"
},
"traceId": {
"type": "array",
"items": {
"type": "string"
}
},
"sessionId": {
"type": "array",
"items": {
"type": "string"
}
},
"observationId": {
"description": "requires traceId",
"type": "array",
"items": {
"type": "string"
}
},
"experimentId": {
"description": "same ID as datasetRunId in createScore",
"type": "array",
"items": {
"type": "string"
}
},
"fromTimestamp": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
},
"toTimestamp": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
}
},
"required": [
"limit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listScores",
"arguments": {
"limit": 50,
"authorUserId": [
"string"
],
"configId": [
"string"
],
"cursor": "string",
"dataType": [
"NUMERIC"
],
"environment": [
"string"
],
"experimentId": [
"string"
],
"fromTimestamp": "2026-05-15T12:00:00.000Z",
"name": [
"string"
],
"observationId": [
"string"
],
"queueId": [
"string"
],
"scoreIds": [
"string"
],
"sessionId": [
"string"
],
"source": [
"API"
],
"toTimestamp": "2026-05-15T12:00:00.000Z",
"traceId": [
"string"
],
"value": [
"string"
],
"valueMax": 1.23,
"valueMin": 1.23
}
}
}getScore
Fetch one score by ID from the current Langfuse project. The score carries a polymorphic value matching its dataType (number, boolean, or string) and a subject describing what it scores: { kind: trace | observation | session | experiment, id }. Score reads are eventually consistent: a score created with createScore may not be returned by getScore immediately. If a newly created score is not found, wait briefly and retry.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"scoreId": {
"type": "string"
}
},
"required": [
"scoreId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getScore",
"arguments": {
"scoreId": "string"
}
}
}createScore
Create one score in the current Langfuse project. Score reads are eventually consistent: after creation, getScore and listScores may not return the new score immediately. Wait briefly and retry reads when confirming creation.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"id": {
"type": "string"
},
"name": {
"type": "string",
"minLength": 1
},
"traceId": {
"description": "Target trace ID.",
"type": "string"
},
"sessionId": {
"description": "Target session ID.",
"type": "string"
},
"datasetRunId": {
"description": "Target dataset run ID.",
"type": "string"
},
"observationId": {
"description": "Optional observation ID for trace-scoped scores.",
"type": "string"
},
"comment": {
"type": "string"
},
"metadata": {},
"environment": {
"type": "string"
},
"queueId": {
"type": "string"
},
"source": {
"type": "string",
"enum": [
"API",
"ANNOTATION"
]
},
"value": {
"description": "Score value. Must be a JSON number for NUMERIC and BOOLEAN scores; numeric strings like \"0.92\" are invalid. Use a string for CATEGORICAL, TEXT, and CORRECTION scores."
},
"dataType": {
"description": "Score data type. When omitted, legacy scoring accepts string or number values.",
"type": "string",
"enum": [
"NUMERIC",
"CATEGORICAL",
"BOOLEAN",
"CORRECTION",
"TEXT"
]
},
"configId": {
"type": "string"
}
},
"required": [
"name",
"value"
],
"additionalProperties": false,
"description": "Create score request. Provide exactly one of traceId, sessionId, or datasetRunId. observationId may only be provided together with traceId."
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "createScore",
"arguments": {
"name": "string",
"value": {},
"comment": "string",
"configId": "string",
"datasetRunId": "string",
"dataType": "NUMERIC",
"environment": "string",
"id": "string",
"metadata": {},
"observationId": "string",
"queueId": "string",
"sessionId": "string",
"source": "API",
"traceId": "string"
}
}
}listScoreConfigs
List score configurations. Returns exactly data and meta at the top level.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"page": {
"default": 1,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
},
"limit": {
"default": 50,
"type": "integer",
"minimum": 1,
"maximum": 100
}
},
"required": [
"page",
"limit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listScoreConfigs",
"arguments": {
"limit": 50,
"page": 1
}
}
}getScoreConfig
Fetch one score configuration by ID from the current Langfuse project. Returns the public score config object directly.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"configId": {
"type": "string"
}
},
"required": [
"configId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getScoreConfig",
"arguments": {
"configId": "string"
}
}
}createScoreConfig
Create a score configuration. Supports numeric, categorical, boolean, and text configs. Boolean configs automatically receive True and False categories.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"name": {
"type": "string",
"minLength": 1,
"maxLength": 35,
"description": "Allowed characters: letters, numbers, spaces, underscores, periods, parentheses, and hyphens."
},
"description": {
"type": "string"
},
"dataType": {
"type": "string",
"enum": [
"NUMERIC",
"CATEGORICAL",
"BOOLEAN",
"TEXT"
],
"description": "Score config type. Numeric range fields only apply to NUMERIC configs; categorical categories only apply to CATEGORICAL configs."
},
"numericMinValue": {
"description": "Minimum allowed value for NUMERIC score configs.",
"type": "number"
},
"numericMaxValue": {
"description": "Maximum allowed value for NUMERIC score configs.",
"type": "number"
},
"categoricalCategories": {
"description": "Allowed categories for CATEGORICAL score configs as an array of { label, value } objects."
}
},
"required": [
"name",
"dataType"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "createScoreConfig",
"arguments": {
"dataType": "NUMERIC",
"name": "string",
"categoricalCategories": {},
"description": "string",
"numericMaxValue": 1.23,
"numericMinValue": 1.23
}
}
}updateScoreConfig
Update a score configuration. Use this to rename, describe, or adjust allowed numeric/category fields.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"configId": {
"type": "string"
},
"name": {
"type": "string",
"minLength": 1,
"maxLength": 35,
"description": "Allowed characters: letters, numbers, spaces, underscores, periods, parentheses, and hyphens."
},
"numericMinValue": {
"description": "Minimum allowed value for NUMERIC score configs.",
"type": "number"
},
"numericMaxValue": {
"description": "Maximum allowed value for NUMERIC score configs.",
"type": "number"
},
"categoricalCategories": {
"description": "Allowed categories for CATEGORICAL score configs as an array of { label, value } objects."
},
"description": {
"type": "string"
}
},
"required": [
"configId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "updateScoreConfig",
"arguments": {
"configId": "string",
"categoricalCategories": {},
"description": "string",
"name": "string",
"numericMaxValue": 1.23,
"numericMinValue": 1.23
}
}
}deleteScoreConfig
Delete a score configuration from the current Langfuse project by archiving it.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"configId": {
"type": "string"
}
},
"required": [
"configId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "deleteScoreConfig",
"arguments": {
"configId": "string"
}
}
}queryMetrics
Requires v4Answer analytics questions about the current Langfuse project, such as usage over time, model costs, latency, errors, scores, or grouped breakdowns by environment, trace, observation, model, user, session, tag, or score name.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"view": {
"type": "string",
"enum": [
"observations",
"scores-numeric",
"scores-categorical",
"scores-boolean"
]
},
"dimensions": {
"default": [],
"type": "array",
"items": {
"type": "object",
"properties": {
"field": {
"type": "string"
}
},
"required": [
"field"
],
"additionalProperties": false
}
},
"metrics": {
"type": "array",
"items": {
"type": "object",
"properties": {
"measure": {
"type": "string"
},
"aggregation": {
"type": "string",
"enum": [
"sum",
"avg",
"count",
"max",
"min",
"p50",
"p75",
"p90",
"p95",
"p99",
"histogram",
"uniq"
]
}
},
"required": [
"measure",
"aggregation"
],
"additionalProperties": false
}
},
"filters": {
"default": [],
"type": "array",
"items": {
"type": "object",
"properties": {
"column": {
"type": "string"
},
"operator": {
"type": "string"
},
"value": {},
"type": {
"type": "string"
},
"key": {
"type": "string"
}
},
"required": [
"column",
"operator",
"value",
"type"
],
"additionalProperties": false
}
},
"timeDimension": {
"type": "object",
"properties": {
"granularity": {
"type": "string",
"enum": [
"auto",
"minute",
"hour",
"day",
"week",
"month"
]
}
},
"required": [
"granularity"
],
"additionalProperties": false
},
"fromTimestamp": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
},
"toTimestamp": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
},
"orderBy": {
"type": "array",
"items": {
"type": "object",
"properties": {
"field": {
"type": "string"
},
"direction": {
"type": "string",
"enum": [
"asc",
"desc"
]
}
},
"required": [
"field",
"direction"
],
"additionalProperties": false
}
},
"config": {
"type": "object",
"properties": {
"bins": {
"type": "integer",
"minimum": 1,
"maximum": 100
},
"row_limit": {
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 1000
}
},
"additionalProperties": false
}
},
"required": [
"view",
"dimensions",
"metrics",
"filters",
"fromTimestamp",
"toTimestamp"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "queryMetrics",
"arguments": {
"dimensions": [],
"filters": [],
"fromTimestamp": "2026-05-15T12:00:00.000Z",
"metrics": [
{
"aggregation": "sum",
"measure": "string"
}
],
"toTimestamp": "2026-05-15T12:00:00.000Z",
"view": "observations",
"config": {
"bins": 1,
"row_limit": 1
},
"orderBy": [
{
"direction": "asc",
"field": "string"
}
],
"timeDimension": {
"granularity": "auto"
}
}
}
}getMetricsSchema
Requires v4Discover which Langfuse metrics can be analyzed and how to group, filter, aggregate, and time-bucket them before calling queryMetrics.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"view": {
"description": "Limit the response to one v2 metrics view",
"type": "string",
"enum": [
"observations",
"scores-numeric",
"scores-categorical",
"scores-boolean"
]
}
},
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getMetricsSchema",
"arguments": {
"view": "observations"
}
}
}listModels
List custom and Langfuse-managed model definitions visible to the current project.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"page": {
"default": 1,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
},
"limit": {
"default": 50,
"type": "integer",
"minimum": 1,
"maximum": 100
}
},
"required": [
"page",
"limit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listModels",
"arguments": {
"limit": 50,
"page": 1
}
}
}createModel
Create a custom model definition for cost tracking/tokenization in the current project.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"modelName": {
"type": "string"
},
"matchPattern": {
"type": "string"
},
"startDate": {
"type": "string"
},
"inputPrice": {
"type": "number",
"minimum": 0
},
"outputPrice": {
"type": "number",
"minimum": 0
},
"totalPrice": {
"type": "number",
"minimum": 0
},
"unit": {
"type": "string",
"enum": [
"TOKENS",
"CHARACTERS",
"MILLISECONDS",
"SECONDS",
"REQUESTS",
"IMAGES"
]
},
"tokenizerId": {
"type": "string",
"enum": [
"openai",
"claude"
]
},
"tokenizerConfig": {},
"pricingTiers": {
"type": "array",
"items": {}
}
},
"required": [
"modelName",
"matchPattern",
"unit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "createModel",
"arguments": {
"matchPattern": "string",
"modelName": "string",
"unit": "TOKENS",
"inputPrice": 1.23,
"outputPrice": 1.23,
"pricingTiers": [
{}
],
"startDate": "string",
"tokenizerConfig": {},
"tokenizerId": "openai",
"totalPrice": 1.23
}
}
}getModel
Get a model definition by ID from the current project scope.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"modelId": {
"type": "string"
}
},
"required": [
"modelId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getModel",
"arguments": {
"modelId": "string"
}
}
}deleteModel
Delete a custom model definition from the current project. Built-in models cannot be deleted.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"modelId": {
"type": "string"
}
},
"required": [
"modelId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "deleteModel",
"arguments": {
"modelId": "string"
}
}
}getMedia
Fetch metadata and a signed download URL for one media asset.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"mediaId": {
"type": "string"
}
},
"required": [
"mediaId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getMedia",
"arguments": {
"mediaId": "string"
}
}
}listManagedEvaluatorTemplates
List the evaluator templates maintained by Langfuse and partners. Copy a returned definition into createEvaluator to create a project evaluator.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"search": {
"type": "string",
"maxLength": 200
},
"category": {
"type": "string",
"minLength": 1
},
"type": {
"type": "string",
"enum": [
"LLM_AS_JUDGE",
"CODE"
]
}
},
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listManagedEvaluatorTemplates",
"arguments": {
"category": "string",
"search": "string",
"type": "LLM_AS_JUDGE"
}
}
}listEvaluators
List evaluators (llm_as_judge and code) defined in the current Langfuse project. Results are paginated.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"page": {
"default": 1,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
},
"limit": {
"default": 50,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 100
}
},
"required": [
"page",
"limit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listEvaluators",
"arguments": {
"limit": 50,
"page": 1
}
}
}getEvaluator
Fetch a single evaluator by id, including its prompt or source code, output definition, and how many evaluation rules reference it.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"evaluatorId": {
"type": "string"
}
},
"required": [
"evaluatorId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getEvaluator",
"arguments": {
"evaluatorId": "string"
}
}
}testEvaluator
Test an evaluator draft or the latest saved version of an evaluator against one observation in the current Langfuse project. For a saved evaluator, provide evaluatorId. For an unsaved draft, omit evaluatorId and provide type plus the matching LLM-as-a-judge or code evaluator fields. Pass the observationId, traceId, and startTime returned by the observation tools. This executes the evaluator, emits an internal trace, and may incur model or code execution cost.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"evaluatorId": {
"description": "Saved evaluator ID. Provide this or a draft evaluator definition, but not both.",
"type": "string",
"minLength": 1
},
"type": {
"type": "string",
"enum": [
"LLM_AS_JUDGE",
"CODE"
]
},
"prompt": {
"type": "string",
"minLength": 1
},
"modelConfig": {
"description": "Optional custom model configuration. Omit to use the project default model.",
"type": "object",
"properties": {
"provider": {
"type": "string",
"minLength": 1
},
"model": {
"type": "string",
"minLength": 1
},
"modelParams": {
"type": "object",
"properties": {
"max_tokens": {
"type": "number"
},
"temperature": {
"type": "number"
},
"top_p": {
"type": "number"
},
"maxReasoningTokens": {
"type": "number"
},
"providerOptions": {
"type": "object",
"propertyNames": {
"type": "string"
},
"additionalProperties": {}
}
},
"additionalProperties": false
}
},
"required": [
"provider",
"model"
],
"additionalProperties": false
},
"outputDefinition": {
"description": "Required for LLM-as-a-judge evaluators. Defines the reasoning and score returned by the evaluator.",
"type": "object",
"properties": {
"dataType": {
"type": "string",
"enum": [
"NUMERIC",
"CATEGORICAL",
"BOOLEAN"
],
"description": "The score type returned by the evaluator."
},
"reasoning": {
"type": "object",
"properties": {
"description": {
"description": "Instructions for the evaluator's reasoning output.",
"type": "string"
}
},
"additionalProperties": false,
"description": "Definition of the evaluator's textual reasoning output."
},
"score": {
"type": "object",
"properties": {
"description": {
"description": "Instructions for the evaluator's score output.",
"type": "string"
},
"minValue": {
"description": "Optional minimum score for NUMERIC evaluators.",
"type": "number"
},
"maxValue": {
"description": "Optional maximum score for NUMERIC evaluators.",
"type": "number"
},
"categories": {
"description": "Allowed score labels for CATEGORICAL evaluators. Provide at least two unique values.",
"type": "array",
"items": {
"type": "string"
}
},
"shouldAllowMultipleMatches": {
"description": "Whether CATEGORICAL evaluators may return multiple score labels.",
"type": "boolean"
}
},
"additionalProperties": false,
"description": "Definition of the evaluator's typed score output. Type-specific fields are validated against dataType."
}
},
"required": [
"dataType",
"reasoning",
"score"
],
"additionalProperties": false
},
"sourceCode": {
"type": "string",
"minLength": 1,
"maxLength": 262144
},
"sourceCodeLanguage": {
"type": "string",
"enum": [
"PYTHON",
"TYPESCRIPT"
]
},
"variableMapping": {
"description": "Variable mappings for LLM-as-a-judge evaluators only.",
"type": "array",
"items": {
"type": "object",
"properties": {
"templateVariable": {
"type": "string"
},
"selectedColumnId": {
"type": "string"
},
"jsonSelector": {
"type": "string"
}
},
"required": [
"templateVariable",
"selectedColumnId"
],
"additionalProperties": false
}
},
"observationId": {
"type": "string",
"minLength": 1
},
"traceId": {
"type": "string",
"minLength": 1
},
"startTime": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
}
},
"required": [
"observationId",
"traceId",
"startTime"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "testEvaluator",
"arguments": {
"observationId": "string",
"startTime": "2026-05-15T12:00:00.000Z",
"traceId": "string",
"evaluatorId": "string",
"modelConfig": {
"model": "string",
"provider": "string",
"modelParams": {
"max_tokens": 1.23,
"maxReasoningTokens": 1.23,
"providerOptions": {
"property": {}
},
"temperature": 1.23,
"top_p": 1.23
}
},
"outputDefinition": {
"dataType": "NUMERIC",
"reasoning": {
"description": "string"
},
"score": {
"categories": [
"string"
],
"description": "string",
"maxValue": 1.23,
"minValue": 1.23,
"shouldAllowMultipleMatches": true
}
},
"prompt": "string",
"sourceCode": "string",
"sourceCodeLanguage": "PYTHON",
"type": "LLM_AS_JUDGE",
"variableMapping": [
{
"selectedColumnId": "string",
"templateVariable": "string",
"jsonSelector": "string"
}
]
}
}
}createEvaluator
Create a new evaluator with a stable id. Names do not act as identity and may be reused. Set type to `LLM_AS_JUDGE` and provide prompt + outputDefinition. Omit modelConfig to use the project default, or provide modelConfig with provider, model, and optional modelParams. For `CODE`, provide sourceCode + sourceCodeLanguage. Use updateEvaluator with the returned evaluatorId to update it or append a new immutable definition version.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"name": {
"type": "string",
"minLength": 1
},
"description": {
"type": "string",
"maxLength": 2000
},
"type": {
"type": "string",
"enum": [
"LLM_AS_JUDGE",
"CODE"
]
},
"prompt": {
"type": "string",
"minLength": 1
},
"modelConfig": {
"description": "Optional custom model configuration. Omit to use the project default model.",
"type": "object",
"properties": {
"provider": {
"type": "string",
"minLength": 1
},
"model": {
"type": "string",
"minLength": 1
},
"modelParams": {
"type": "object",
"properties": {
"max_tokens": {
"type": "number"
},
"temperature": {
"type": "number"
},
"top_p": {
"type": "number"
},
"maxReasoningTokens": {
"type": "number"
},
"providerOptions": {
"type": "object",
"propertyNames": {
"type": "string"
},
"additionalProperties": {}
}
},
"additionalProperties": false
}
},
"required": [
"provider",
"model"
],
"additionalProperties": false
},
"outputDefinition": {
"description": "Required for LLM-as-a-judge evaluators. Defines the reasoning and score returned by the evaluator.",
"type": "object",
"properties": {
"dataType": {
"type": "string",
"enum": [
"NUMERIC",
"CATEGORICAL",
"BOOLEAN"
],
"description": "The score type returned by the evaluator."
},
"reasoning": {
"type": "object",
"properties": {
"description": {
"description": "Instructions for the evaluator's reasoning output.",
"type": "string"
}
},
"additionalProperties": false,
"description": "Definition of the evaluator's textual reasoning output."
},
"score": {
"type": "object",
"properties": {
"description": {
"description": "Instructions for the evaluator's score output.",
"type": "string"
},
"minValue": {
"description": "Optional minimum score for NUMERIC evaluators.",
"type": "number"
},
"maxValue": {
"description": "Optional maximum score for NUMERIC evaluators.",
"type": "number"
},
"categories": {
"description": "Allowed score labels for CATEGORICAL evaluators. Provide at least two unique values.",
"type": "array",
"items": {
"type": "string"
}
},
"shouldAllowMultipleMatches": {
"description": "Whether CATEGORICAL evaluators may return multiple score labels.",
"type": "boolean"
}
},
"additionalProperties": false,
"description": "Definition of the evaluator's typed score output. Type-specific fields are validated against dataType."
}
},
"required": [
"dataType",
"reasoning",
"score"
],
"additionalProperties": false
},
"sourceCode": {
"type": "string",
"minLength": 1,
"maxLength": 262144
},
"sourceCodeLanguage": {
"type": "string",
"enum": [
"PYTHON",
"TYPESCRIPT"
]
},
"variableMapping": {
"description": "Variable mappings for LLM-as-a-judge evaluators only.",
"type": "array",
"items": {
"type": "object",
"properties": {
"templateVariable": {
"type": "string"
},
"selectedColumnId": {
"type": "string"
},
"jsonSelector": {
"type": "string"
}
},
"required": [
"templateVariable",
"selectedColumnId"
],
"additionalProperties": false
}
}
},
"required": [
"name",
"type"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "createEvaluator",
"arguments": {
"name": "string",
"type": "LLM_AS_JUDGE",
"description": "string",
"modelConfig": {
"model": "string",
"provider": "string",
"modelParams": {
"max_tokens": 1.23,
"maxReasoningTokens": 1.23,
"providerOptions": {
"property": {}
},
"temperature": 1.23,
"top_p": 1.23
}
},
"outputDefinition": {
"dataType": "NUMERIC",
"reasoning": {
"description": "string"
},
"score": {
"categories": [
"string"
],
"description": "string",
"maxValue": 1.23,
"minValue": 1.23,
"shouldAllowMultipleMatches": true
}
},
"prompt": "string",
"sourceCode": "string",
"sourceCodeLanguage": "PYTHON",
"variableMapping": [
{
"selectedColumnId": "string",
"templateVariable": "string",
"jsonSelector": "string"
}
]
}
}
}updateEvaluator
Update an evaluator by stable id. Definition changes append an immutable version; name and description changes do not. Set type to `LLM_AS_JUDGE` and provide prompt + outputDefinition. Omit modelConfig to use the project default, or provide modelConfig with provider, model, and optional modelParams. For `CODE`, provide sourceCode + sourceCodeLanguage.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"name": {
"type": "string",
"minLength": 1
},
"description": {
"type": "string",
"maxLength": 2000
},
"type": {
"type": "string",
"enum": [
"LLM_AS_JUDGE",
"CODE"
]
},
"prompt": {
"type": "string",
"minLength": 1
},
"modelConfig": {
"description": "Optional custom model configuration. Omit to use the project default model.",
"type": "object",
"properties": {
"provider": {
"type": "string",
"minLength": 1
},
"model": {
"type": "string",
"minLength": 1
},
"modelParams": {
"type": "object",
"properties": {
"max_tokens": {
"type": "number"
},
"temperature": {
"type": "number"
},
"top_p": {
"type": "number"
},
"maxReasoningTokens": {
"type": "number"
},
"providerOptions": {
"type": "object",
"propertyNames": {
"type": "string"
},
"additionalProperties": {}
}
},
"additionalProperties": false
}
},
"required": [
"provider",
"model"
],
"additionalProperties": false
},
"outputDefinition": {
"description": "Required for LLM-as-a-judge evaluators. Defines the reasoning and score returned by the evaluator.",
"type": "object",
"properties": {
"dataType": {
"type": "string",
"enum": [
"NUMERIC",
"CATEGORICAL",
"BOOLEAN"
],
"description": "The score type returned by the evaluator."
},
"reasoning": {
"type": "object",
"properties": {
"description": {
"description": "Instructions for the evaluator's reasoning output.",
"type": "string"
}
},
"additionalProperties": false,
"description": "Definition of the evaluator's textual reasoning output."
},
"score": {
"type": "object",
"properties": {
"description": {
"description": "Instructions for the evaluator's score output.",
"type": "string"
},
"minValue": {
"description": "Optional minimum score for NUMERIC evaluators.",
"type": "number"
},
"maxValue": {
"description": "Optional maximum score for NUMERIC evaluators.",
"type": "number"
},
"categories": {
"description": "Allowed score labels for CATEGORICAL evaluators. Provide at least two unique values.",
"type": "array",
"items": {
"type": "string"
}
},
"shouldAllowMultipleMatches": {
"description": "Whether CATEGORICAL evaluators may return multiple score labels.",
"type": "boolean"
}
},
"additionalProperties": false,
"description": "Definition of the evaluator's typed score output. Type-specific fields are validated against dataType."
}
},
"required": [
"dataType",
"reasoning",
"score"
],
"additionalProperties": false
},
"sourceCode": {
"type": "string",
"minLength": 1,
"maxLength": 262144
},
"sourceCodeLanguage": {
"type": "string",
"enum": [
"PYTHON",
"TYPESCRIPT"
]
},
"variableMapping": {
"description": "Variable mappings for LLM-as-a-judge evaluators only.",
"type": "array",
"items": {
"type": "object",
"properties": {
"templateVariable": {
"type": "string"
},
"selectedColumnId": {
"type": "string"
},
"jsonSelector": {
"type": "string"
}
},
"required": [
"templateVariable",
"selectedColumnId"
],
"additionalProperties": false
}
},
"evaluatorId": {
"type": "string"
}
},
"required": [
"name",
"type",
"evaluatorId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "updateEvaluator",
"arguments": {
"evaluatorId": "string",
"name": "string",
"type": "LLM_AS_JUDGE",
"description": "string",
"modelConfig": {
"model": "string",
"provider": "string",
"modelParams": {
"max_tokens": 1.23,
"maxReasoningTokens": 1.23,
"providerOptions": {
"property": {}
},
"temperature": 1.23,
"top_p": 1.23
}
},
"outputDefinition": {
"dataType": "NUMERIC",
"reasoning": {
"description": "string"
},
"score": {
"categories": [
"string"
],
"description": "string",
"maxValue": 1.23,
"minValue": 1.23,
"shouldAllowMultipleMatches": true
}
},
"prompt": "string",
"sourceCode": "string",
"sourceCodeLanguage": "PYTHON",
"variableMapping": [
{
"selectedColumnId": "string",
"templateVariable": "string",
"jsonSelector": "string"
}
]
}
}
}deleteEvaluator
Delete an evaluator. This cannot be undone.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"evaluatorId": {
"type": "string"
}
},
"required": [
"evaluatorId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "deleteEvaluator",
"arguments": {
"evaluatorId": "string"
}
}
}listEvaluationRules
List observation evaluation rules in the current Langfuse project, including all evaluator assignments. Results are paginated.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"page": {
"default": 1,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
},
"limit": {
"default": 50,
"type": "integer",
"minimum": 1,
"maximum": 100
},
"orderBy": {
"type": "object",
"properties": {
"column": {
"type": "string",
"enum": [
"name",
"enabled",
"sampling",
"createdAt",
"updatedAt"
]
},
"order": {
"type": "string",
"enum": [
"ASC",
"DESC"
]
}
},
"required": [
"column",
"order"
],
"additionalProperties": false
},
"search": {
"type": "string",
"maxLength": 200
},
"enabled": {
"type": "boolean"
},
"targetObjects": {
"minItems": 1,
"maxItems": 2,
"type": "array",
"items": {
"type": "string",
"enum": [
"event",
"experiment"
]
}
},
"filter": {
"description": "Conditions filtering the returned evaluation rules.",
"type": "array",
"items": {
"type": "object",
"properties": {
"column": {
"type": "string"
},
"operator": {
"type": "string"
},
"value": {},
"type": {
"type": "string"
},
"key": {
"type": "string"
}
},
"required": [
"column",
"operator",
"value",
"type"
],
"additionalProperties": false,
"description": "Observation filter condition, e.g. {\"column\":\"version\",\"operator\":\"=\",\"value\":\"1.0.0\",\"type\":\"string\"}. Use `key` for object columns such as `metadata`."
}
}
},
"required": [
"page",
"limit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listEvaluationRules",
"arguments": {
"limit": 50,
"page": 1,
"enabled": true,
"filter": [
{
"column": "string",
"operator": "string",
"type": "string",
"value": {},
"key": "string"
}
],
"orderBy": {
"column": "name",
"order": "ASC"
},
"search": "string",
"targetObjects": [
"event"
]
}
}
}getEvaluationRule
Fetch an observation evaluation rule by ID, including all evaluator assignments, filters, sampling, and status.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"evaluationRuleId": {
"type": "string"
}
},
"required": [
"evaluationRuleId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getEvaluationRule",
"arguments": {
"evaluationRuleId": "string"
}
}
}createEvaluationRule
Create an observation evaluation rule with one or more evaluator assignments. Each assignment references a project evaluator by stable ID. LLM evaluator assignments may override their variable mapping; code evaluator assignments must omit it.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"name": {
"type": "string",
"minLength": 1
},
"sampling": {
"type": "number",
"minimum": 0,
"maximum": 1
},
"enabled": {
"type": "boolean"
},
"evaluatorAssignments": {
"minItems": 1,
"maxItems": 100,
"type": "array",
"items": {
"type": "object",
"properties": {
"evaluatorId": {
"type": "string",
"minLength": 1,
"description": "Stable project evaluator ID."
},
"variableMapping": {
"type": "array",
"items": {
"type": "object",
"properties": {
"variable": {
"type": "string",
"minLength": 1
},
"source": {
"type": "string",
"enum": [
"input",
"output",
"metadata",
"tool_calls"
]
},
"jsonPath": {
"type": "string",
"minLength": 1
}
},
"required": [
"variable",
"source"
],
"additionalProperties": false
},
"description": "Optional rule-specific variable mapping for LLM evaluators. Omit for code evaluators, whose mapping is managed by Langfuse."
}
},
"required": [
"evaluatorId"
],
"additionalProperties": false
}
},
"filter": {
"description": "Conditions selecting which observations the rule runs on.",
"type": "array",
"items": {
"type": "object",
"properties": {
"column": {
"type": "string"
},
"operator": {
"type": "string"
},
"value": {},
"type": {
"type": "string"
},
"key": {
"type": "string"
}
},
"required": [
"column",
"operator",
"value",
"type"
],
"additionalProperties": false,
"description": "Observation filter condition, e.g. {\"column\":\"version\",\"operator\":\"=\",\"value\":\"1.0.0\",\"type\":\"string\"}. Use `key` for object columns such as `metadata`."
}
}
},
"required": [
"name",
"sampling",
"enabled",
"evaluatorAssignments"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "createEvaluationRule",
"arguments": {
"enabled": true,
"evaluatorAssignments": [
{
"evaluatorId": "string",
"variableMapping": [
{
"source": "input",
"variable": "string",
"jsonPath": "string"
}
]
}
],
"name": "string",
"sampling": 1.23,
"filter": [
{
"column": "string",
"operator": "string",
"type": "string",
"value": {},
"key": "string"
}
]
}
}
}updateEvaluationRule
Update an observation evaluation rule, including replacing all evaluator assignments.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"name": {
"type": "string",
"minLength": 1
},
"sampling": {
"type": "number",
"minimum": 0,
"maximum": 1
},
"enabled": {
"type": "boolean"
},
"evaluationRuleId": {
"type": "string"
},
"filter": {
"type": "array",
"items": {
"type": "object",
"properties": {
"column": {
"type": "string"
},
"operator": {
"type": "string"
},
"value": {},
"type": {
"type": "string"
},
"key": {
"type": "string"
}
},
"required": [
"column",
"operator",
"value",
"type"
],
"additionalProperties": false,
"description": "Observation filter condition, e.g. {\"column\":\"version\",\"operator\":\"=\",\"value\":\"1.0.0\",\"type\":\"string\"}. Use `key` for object columns such as `metadata`."
}
},
"evaluatorAssignments": {
"maxItems": 100,
"type": "array",
"items": {
"type": "object",
"properties": {
"evaluatorId": {
"type": "string",
"minLength": 1,
"description": "Stable project evaluator ID."
},
"variableMapping": {
"type": "array",
"items": {
"type": "object",
"properties": {
"variable": {
"type": "string",
"minLength": 1
},
"source": {
"type": "string",
"enum": [
"input",
"output",
"metadata",
"tool_calls"
]
},
"jsonPath": {
"type": "string",
"minLength": 1
}
},
"required": [
"variable",
"source"
],
"additionalProperties": false
},
"description": "Optional rule-specific variable mapping for LLM evaluators. Omit for code evaluators, whose mapping is managed by Langfuse."
}
},
"required": [
"evaluatorId"
],
"additionalProperties": false
}
}
},
"required": [
"evaluationRuleId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "updateEvaluationRule",
"arguments": {
"evaluationRuleId": "string",
"enabled": true,
"evaluatorAssignments": [
{
"evaluatorId": "string",
"variableMapping": [
{
"source": "input",
"variable": "string",
"jsonPath": "string"
}
]
}
],
"filter": [
{
"column": "string",
"operator": "string",
"type": "string",
"value": {},
"key": "string"
}
],
"name": "string",
"sampling": 1.23
}
}
}attachEvaluatorToEvaluationRule
Attach a project evaluator to an observation evaluation rule using their stable IDs. For LLM evaluators, omit variableMapping to inherit the evaluator version's mapping or provide an override. Code evaluators must omit variableMapping.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"evaluationRuleId": {
"type": "string",
"description": "Stable evaluation rule ID."
},
"evaluatorId": {
"type": "string",
"minLength": 1,
"description": "Stable project evaluator ID."
},
"variableMapping": {
"type": "array",
"items": {
"type": "object",
"properties": {
"variable": {
"type": "string",
"minLength": 1
},
"source": {
"type": "string",
"enum": [
"input",
"output",
"metadata",
"tool_calls"
]
},
"jsonPath": {
"type": "string",
"minLength": 1
}
},
"required": [
"variable",
"source"
],
"additionalProperties": false
},
"description": "Optional rule-specific variable mapping for LLM evaluators. Omit for code evaluators, whose mapping is managed by Langfuse."
}
},
"required": [
"evaluationRuleId",
"evaluatorId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "attachEvaluatorToEvaluationRule",
"arguments": {
"evaluationRuleId": "string",
"evaluatorId": "string",
"variableMapping": [
{
"source": "input",
"variable": "string",
"jsonPath": "string"
}
]
}
}
}detachEvaluatorFromEvaluationRule
Detach a project evaluator from an observation evaluation rule using their stable IDs.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"evaluationRuleId": {
"type": "string",
"description": "Stable evaluation rule ID."
},
"evaluatorId": {
"type": "string",
"minLength": 1,
"description": "Stable project evaluator ID."
}
},
"required": [
"evaluationRuleId",
"evaluatorId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "detachEvaluatorFromEvaluationRule",
"arguments": {
"evaluationRuleId": "string",
"evaluatorId": "string"
}
}
}deleteEvaluationRule
Delete an observation evaluation rule by ID. This cannot be undone.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"evaluationRuleId": {
"type": "string"
}
},
"required": [
"evaluationRuleId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "deleteEvaluationRule",
"arguments": {
"evaluationRuleId": "string"
}
}
}listDashboardWidgets
List dashboard widgets in the current project.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"page": {
"default": 1,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
},
"limit": {
"default": 50,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 100
}
},
"required": [
"page",
"limit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listDashboardWidgets",
"arguments": {
"limit": 50,
"page": 1
}
}
}createDashboardWidget
Create a dashboard widget (a standalone chart definition you place on any dashboard). Widgets are useful to visualize Langfuse project data and give informative breakdowns to the user. This creates the widget only; place it on a dashboard with the addDashboardPlacement tool. The result includes a url field; use it to link to the created widget.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"name": {
"type": "string",
"minLength": 1,
"description": "Human-readable widget name."
},
"description": {
"description": "Human-readable widget description. Defaults to empty.",
"type": "string"
},
"view": {
"type": "string",
"enum": [
"observations",
"scores-numeric",
"scores-boolean",
"scores-categorical"
],
"description": "Data view for the widget. Traces widgets are not supported by this unstable API."
},
"dimensions": {
"type": "array",
"items": {
"type": "object",
"properties": {
"field": {
"type": "string",
"minLength": 1
}
},
"required": [
"field"
],
"additionalProperties": false
},
"description": "Breakdown dimensions. Non-pivot charts support at most one dimension."
},
"metrics": {
"minItems": 1,
"type": "array",
"items": {
"type": "object",
"properties": {
"measure": {
"type": "string",
"minLength": 1
},
"agg": {
"type": "string",
"enum": [
"sum",
"avg",
"count",
"max",
"min",
"p50",
"p75",
"p90",
"p95",
"p99",
"histogram",
"uniq"
]
}
},
"required": [
"measure",
"agg"
],
"additionalProperties": false
},
"description": "Measures and aggregations to plot."
},
"filters": {
"type": "array",
"items": {
"type": "object",
"properties": {
"column": {
"type": "string"
},
"operator": {
"type": "string"
},
"type": {
"type": "string"
},
"value": {},
"key": {
"type": "string"
}
},
"required": [
"column",
"operator",
"type"
],
"additionalProperties": {}
},
"description": "Widget filters in the same shape as exported dashboard widget JSON."
},
"chartType": {
"type": "string",
"enum": [
"LINE_TIME_SERIES",
"AREA_TIME_SERIES",
"BAR_TIME_SERIES",
"HORIZONTAL_BAR",
"VERTICAL_BAR",
"PIE",
"NUMBER",
"HISTOGRAM",
"PIVOT_TABLE"
]
},
"chartConfig": {
"description": "Chart-specific config. Optional; type defaults to chartType and must match it when given.",
"type": "object",
"properties": {
"type": {
"type": "string",
"enum": [
"LINE_TIME_SERIES",
"AREA_TIME_SERIES",
"BAR_TIME_SERIES",
"HORIZONTAL_BAR",
"VERTICAL_BAR",
"PIE",
"NUMBER",
"HISTOGRAM",
"PIVOT_TABLE"
]
},
"row_limit": {
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 1000
},
"show_value_labels": {
"type": "boolean"
},
"bins": {
"type": "integer",
"minimum": 1,
"maximum": 100
},
"defaultSort": {
"type": "object",
"properties": {
"column": {
"type": "string"
},
"order": {
"type": "string",
"enum": [
"ASC",
"DESC"
]
}
},
"required": [
"column",
"order"
],
"additionalProperties": false
}
},
"additionalProperties": false
}
},
"required": [
"name",
"view",
"dimensions",
"metrics",
"filters",
"chartType"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "createDashboardWidget",
"arguments": {
"chartType": "LINE_TIME_SERIES",
"dimensions": [
{
"field": "string"
}
],
"filters": [
{
"column": "string",
"operator": "string",
"type": "string",
"key": "string",
"value": {}
}
],
"metrics": [
{
"agg": "sum",
"measure": "string"
}
],
"name": "string",
"view": "observations",
"chartConfig": {
"bins": 1,
"defaultSort": {
"column": "string",
"order": "ASC"
},
"row_limit": 1,
"show_value_labels": true,
"type": "LINE_TIME_SERIES"
},
"description": "string"
}
}
}getDashboardWidget
Get a dashboard widget by ID.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"widgetId": {
"type": "string"
}
},
"required": [
"widgetId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getDashboardWidget",
"arguments": {
"widgetId": "string"
}
}
}updateDashboardWidget
Partially update a dashboard widget.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"widgetId": {
"type": "string"
},
"name": {
"type": "string",
"minLength": 1
},
"description": {
"type": "string"
},
"view": {
"type": "string",
"enum": [
"observations",
"scores-numeric",
"scores-boolean",
"scores-categorical"
]
},
"dimensions": {
"type": "array",
"items": {
"type": "object",
"properties": {
"field": {
"type": "string"
}
},
"required": [
"field"
],
"additionalProperties": false
}
},
"metrics": {
"type": "array",
"items": {
"type": "object",
"properties": {
"measure": {
"type": "string"
},
"agg": {
"type": "string",
"enum": [
"sum",
"avg",
"count",
"max",
"min",
"p50",
"p75",
"p90",
"p95",
"p99",
"histogram",
"uniq"
]
}
},
"required": [
"measure",
"agg"
],
"additionalProperties": false
}
},
"filters": {
"type": "array",
"items": {
"type": "object",
"properties": {
"column": {
"type": "string"
},
"operator": {
"type": "string"
},
"type": {
"type": "string"
},
"value": {},
"key": {
"type": "string"
}
},
"required": [
"column",
"operator",
"type"
],
"additionalProperties": {}
}
},
"chartType": {
"type": "string",
"enum": [
"LINE_TIME_SERIES",
"AREA_TIME_SERIES",
"BAR_TIME_SERIES",
"HORIZONTAL_BAR",
"VERTICAL_BAR",
"PIE",
"NUMBER",
"HISTOGRAM",
"PIVOT_TABLE"
]
},
"chartConfig": {
"type": "object",
"properties": {
"type": {
"type": "string",
"enum": [
"LINE_TIME_SERIES",
"AREA_TIME_SERIES",
"BAR_TIME_SERIES",
"HORIZONTAL_BAR",
"VERTICAL_BAR",
"PIE",
"NUMBER",
"HISTOGRAM",
"PIVOT_TABLE"
]
},
"row_limit": {
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 1000
},
"show_value_labels": {
"type": "boolean"
},
"bins": {
"type": "integer",
"minimum": 1,
"maximum": 100
},
"defaultSort": {
"type": "object",
"properties": {
"column": {
"type": "string"
},
"order": {
"type": "string",
"enum": [
"ASC",
"DESC"
]
}
},
"required": [
"column",
"order"
],
"additionalProperties": false
}
},
"additionalProperties": false
}
},
"required": [
"widgetId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "updateDashboardWidget",
"arguments": {
"widgetId": "string",
"chartConfig": {
"bins": 1,
"defaultSort": {
"column": "string",
"order": "ASC"
},
"row_limit": 1,
"show_value_labels": true,
"type": "LINE_TIME_SERIES"
},
"chartType": "LINE_TIME_SERIES",
"description": "string",
"dimensions": [
{
"field": "string"
}
],
"filters": [
{
"column": "string",
"operator": "string",
"type": "string",
"key": "string",
"value": {}
}
],
"metrics": [
{
"agg": "sum",
"measure": "string"
}
],
"name": "string",
"view": "observations"
}
}
}deleteDashboardWidget
Delete a dashboard widget. It must first be removed from every dashboard placement.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"widgetId": {
"type": "string"
}
},
"required": [
"widgetId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "deleteDashboardWidget",
"arguments": {
"widgetId": "string"
}
}
}listDashboards
List editable dashboards in the current project.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"page": {
"default": 1,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
},
"limit": {
"default": 50,
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 100
}
},
"required": [
"page",
"limit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listDashboards",
"arguments": {
"limit": 50,
"page": 1
}
}
}getDashboard
Get an editable dashboard by ID, including its current layout: definition.widgets lists every placement with 12-column-grid coordinates (x/y top-left cell, width/height in cells).
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"dashboardId": {
"type": "string"
}
},
"required": [
"dashboardId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getDashboard",
"arguments": {
"dashboardId": "string"
}
}
}createDashboard
Create an editable dashboard.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"name": {
"type": "string",
"minLength": 1
},
"description": {
"type": "string"
},
"filters": {
"type": "array",
"items": {
"type": "object",
"properties": {},
"additionalProperties": {}
}
},
"definition": {
"type": "object",
"properties": {
"widgets": {
"type": "array",
"items": {
"type": "object",
"properties": {},
"additionalProperties": {}
}
}
},
"required": [
"widgets"
],
"additionalProperties": false
}
},
"required": [
"name"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "createDashboard",
"arguments": {
"name": "string",
"definition": {
"widgets": [
{
"property": {}
}
]
},
"description": "string",
"filters": [
{
"property": {}
}
]
}
}
}updateDashboard
Partially update dashboard metadata, filters, or its complete definition.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"dashboardId": {
"type": "string"
},
"name": {
"type": "string",
"minLength": 1
},
"description": {
"type": "string"
},
"filters": {
"type": "array",
"items": {
"type": "object",
"properties": {},
"additionalProperties": {}
}
},
"definition": {
"type": "object",
"properties": {
"widgets": {
"type": "array",
"items": {
"type": "object",
"properties": {},
"additionalProperties": {}
}
}
},
"required": [
"widgets"
],
"additionalProperties": false
}
},
"required": [
"dashboardId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "updateDashboard",
"arguments": {
"dashboardId": "string",
"definition": {
"widgets": [
{
"property": {}
}
]
},
"description": "string",
"filters": [
{
"property": {}
}
],
"name": "string"
}
}
}deleteDashboard
Delete an editable dashboard.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"dashboardId": {
"type": "string"
}
},
"required": [
"dashboardId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "deleteDashboard",
"arguments": {
"dashboardId": "string"
}
}
}addDashboardPlacement
Add a widget or preset placement to a dashboard's 12-column grid. Prefer omitting id and position: the server generates an id and appends the tile below existing ones at the default 6x6 size. Explicit positions are not checked for overlap. After adding, call getDashboard to verify the full grid arrangement; use updateDashboardPlacement to move or resize the new tile when needed. Returns the created placement.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"dashboardId": {
"type": "string"
},
"type": {
"type": "string",
"enum": [
"widget",
"preset"
]
},
"id": {
"type": "string"
},
"widgetId": {
"type": "string"
},
"presetId": {
"type": "string"
},
"x": {
"type": "integer",
"minimum": 0,
"maximum": 9007199254740991
},
"y": {
"type": "integer",
"minimum": 0,
"maximum": 9007199254740991
},
"width": {
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
},
"height": {
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
}
},
"required": [
"dashboardId",
"type"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "addDashboardPlacement",
"arguments": {
"dashboardId": "string",
"type": "widget",
"height": 1,
"id": "string",
"presetId": "string",
"widgetId": "string",
"width": 1,
"x": 1,
"y": 1
}
}
}updateDashboardPlacement
Move or resize an existing dashboard placement on the 12-column grid. Pass any of x, y (top-left cell), width, height (in cells); omitted fields keep their current value. The placement's content and id cannot change. Use getDashboard to read the current layout first. Overlaps are not checked. Returns the updated placement.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"dashboardId": {
"type": "string"
},
"placementId": {
"type": "string"
},
"x": {
"type": "integer",
"minimum": 0,
"maximum": 9007199254740991
},
"y": {
"type": "integer",
"minimum": 0,
"maximum": 9007199254740991
},
"width": {
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
},
"height": {
"type": "integer",
"exclusiveMinimum": 0,
"maximum": 9007199254740991
}
},
"required": [
"dashboardId",
"placementId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "updateDashboardPlacement",
"arguments": {
"dashboardId": "string",
"placementId": "string",
"height": 1,
"width": 1,
"x": 1,
"y": 1
}
}
}deleteDashboardPlacement
Remove a placement from a dashboard without deleting the underlying widget.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"dashboardId": {
"type": "string"
},
"placementId": {
"type": "string"
}
},
"required": [
"dashboardId",
"placementId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "deleteDashboardPlacement",
"arguments": {
"dashboardId": "string",
"placementId": "string"
}
}
}submitFeedback
Submit explicit user-approved feedback to the Langfuse team about Langfuse skills, MCP tools, CLI, docs, or public API. Before calling, ask the user for permission and show the exact feedback payload, including any optional goal/use-case context. If the user wants a reply, ask them to include their email address in the feedback text; only use an address they explicitly provide and show it in the exact payload preview. Do not include secrets, credentials, customer/project data, trace payloads, or unrelated context; the only contact detail to include is an explicitly provided reply email.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"targetType": {
"type": "string",
"enum": [
"skill",
"mcp-tool",
"cli",
"docs",
"public-api",
"other"
],
"description": "Category of the thing the feedback is about."
},
"target": {
"type": "string",
"minLength": 1,
"maxLength": 200,
"description": "The specific instance within targetType: the skill name, MCP tool name, CLI command, API endpoint path, or docs page path (e.g. 'queryMetrics', '/docs/mcp'). An identifier, not a sentence."
},
"feedback": {
"type": "string",
"minLength": 1,
"maxLength": 3000,
"description": "The concise feedback text approved by the user."
},
"goal": {
"description": "Optional user-approved goal or use case they were trying to achieve. Do not infer or add secrets, customer data, trace payloads, or broad unrelated context.",
"type": "string",
"minLength": 1,
"maxLength": 1500
},
"referenceUrl": {
"description": "Optional URL reference. Langfuse stores it as text only.",
"type": "string",
"maxLength": 2048,
"format": "uri"
}
},
"required": [
"targetType",
"target",
"feedback"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "submitFeedback",
"arguments": {
"feedback": "string",
"target": "string",
"targetType": "skill",
"goal": "string",
"referenceUrl": "https://example.com"
}
}
}listExperiments
Requires v4List experiments in the current Langfuse project with cursor-based pagination. Use this to find experiment IDs, inspect experiment summaries, and optionally include metadata or experiment-level scores. Results are sorted newest first by the latest event for each experiment, not by the returned experiment startTime. fromStartTime is required. Time filters and cursor bounds are applied before experiments are grouped, so a time range can return partial experiment aggregates.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"fields": {
"description": "Response field groups to include. Available groups: core, metadata, scores.",
"default": [
"core"
],
"type": "array",
"items": {
"type": "string",
"enum": [
"core",
"metadata",
"scores"
]
}
},
"limit": {
"default": 50,
"type": "integer",
"minimum": 1,
"maximum": 100
},
"scoreLimit": {
"default": 50,
"type": "integer",
"minimum": 1,
"maximum": 50
},
"cursor": {
"type": "string",
"description": "Base64url-encoded cursor for pagination"
},
"fromStartTime": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
},
"toStartTime": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
},
"id": {
"type": "array",
"items": {
"type": "string"
}
},
"name": {
"type": "array",
"items": {
"type": "string"
}
},
"datasetId": {
"type": "array",
"items": {
"type": "string"
}
},
"filter": {
"description": "Advanced experiment filters as objects with column, operator, value, and type. Supported columns: id, name, datasetId.",
"type": "array",
"items": {
"type": "object",
"properties": {
"column": {
"type": "string"
},
"operator": {
"type": "string"
},
"value": {},
"type": {
"type": "string"
},
"key": {
"type": "string"
}
},
"required": [
"column",
"operator",
"value",
"type"
],
"additionalProperties": false
}
}
},
"required": [
"fields",
"limit",
"scoreLimit",
"fromStartTime"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listExperiments",
"arguments": {
"fields": [
"core"
],
"fromStartTime": "2026-05-15T12:00:00.000Z",
"limit": 50,
"scoreLimit": 50,
"cursor": "string",
"datasetId": [
"string"
],
"filter": [
{
"column": "string",
"operator": "string",
"type": "string",
"value": {},
"key": "string"
}
],
"id": [
"string"
],
"name": [
"string"
],
"toStartTime": "2026-05-15T12:00:00.000Z"
}
}
}listExperimentItems
Requires v4List experiment items in the current Langfuse project with cursor-based pagination. Use this to inspect experiment item inputs, outputs, expected outputs, metadata, and optionally item or trace scores. Results are sorted newest first by experiment item startTime. fromStartTime is required. Request io and metadata fields only when needed because they can be large.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"fields": {
"description": "Response field groups to include. Available groups: core, dataset, io, metadata, itemMetadata, experimentMetadata, scores.",
"default": [
"core",
"dataset"
],
"type": "array",
"items": {
"type": "string",
"enum": [
"core",
"dataset",
"io",
"metadata",
"itemMetadata",
"experimentMetadata",
"scores"
]
}
},
"limit": {
"default": 50,
"type": "integer",
"minimum": 1,
"maximum": 100
},
"scoreLimit": {
"default": 50,
"type": "integer",
"minimum": 1,
"maximum": 50
},
"cursor": {
"type": "string",
"description": "Base64url-encoded cursor for pagination"
},
"fromStartTime": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
},
"toStartTime": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
},
"experimentId": {
"type": "array",
"items": {
"type": "string"
}
},
"experimentName": {
"type": "array",
"items": {
"type": "string"
}
},
"experimentItemId": {
"type": "array",
"items": {
"type": "string"
}
},
"datasetId": {
"type": "array",
"items": {
"type": "string"
}
},
"filter": {
"description": "Advanced experiment item filters as objects with column, operator, value, and type. Supported columns: experimentId, experimentName, experimentItemId, datasetId.",
"type": "array",
"items": {
"type": "object",
"properties": {
"column": {
"type": "string"
},
"operator": {
"type": "string"
},
"value": {},
"type": {
"type": "string"
},
"key": {
"type": "string"
}
},
"required": [
"column",
"operator",
"value",
"type"
],
"additionalProperties": false
}
}
},
"required": [
"fields",
"limit",
"scoreLimit",
"fromStartTime"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listExperimentItems",
"arguments": {
"fields": [
"core",
"dataset"
],
"fromStartTime": "2026-05-15T12:00:00.000Z",
"limit": 50,
"scoreLimit": 50,
"cursor": "string",
"datasetId": [
"string"
],
"experimentId": [
"string"
],
"experimentItemId": [
"string"
],
"experimentName": [
"string"
],
"filter": [
{
"column": "string",
"operator": "string",
"type": "string",
"value": {},
"key": "string"
}
],
"toStartTime": "2026-05-15T12:00:00.000Z"
}
}
}listAlerts
List alerts, optionally filtered by severity or tags and ordered by alert properties.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"page": {
"default": 1,
"type": "number",
"minimum": 0
},
"limit": {
"default": 50,
"type": "integer",
"minimum": 1,
"maximum": 100
},
"orderBy": {
"type": "object",
"properties": {
"column": {
"type": "string",
"enum": [
"name",
"status",
"severity",
"severityChangedAt",
"alertedAt",
"createdAt",
"updatedAt"
]
},
"order": {
"type": "string",
"enum": [
"ASC",
"DESC"
]
}
},
"required": [
"column",
"order"
],
"additionalProperties": false
},
"filter": {
"description": "Filter alerts by severity or tags.",
"type": "array",
"items": {
"type": "object",
"properties": {
"column": {
"type": "string"
},
"operator": {
"type": "string"
},
"value": {},
"type": {
"type": "string"
},
"key": {
"type": "string"
}
},
"required": [
"column",
"operator",
"value",
"type"
],
"additionalProperties": false
}
}
},
"required": [
"page",
"limit"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "listAlerts",
"arguments": {
"limit": 50,
"page": 1,
"filter": [
{
"column": "string",
"operator": "string",
"type": "string",
"value": {},
"key": "string"
}
],
"orderBy": {
"column": "name",
"order": "ASC"
}
}
}
}getAlert
Get an alert by ID.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"monitorId": {
"type": "string",
"description": "ID of the alert to retrieve."
}
},
"required": [
"monitorId"
],
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getAlert",
"arguments": {
"monitorId": "string"
}
}
}getV4MigrationData
Get project-specific evidence for upgrading to Langfuse v4, including SDK versions and compatibility, experiment instrumentation, legacy integrations, deprecated API usage, and trace-level evaluators. Use this before giving v4 migration guidance.
Input schema and generated requestExpandCollapse
Input schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {},
"additionalProperties": false
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getV4MigrationData",
"arguments": {}
}
}Langfuse Docs MCP
Unauthenticated MCP server for Langfuse documentation search and retrieval.
https://langfuse.com/api/mcpClient setup
Cursor mcp.json
json
{
"mcpServers": {
"langfuse-docs": {
"url": "https://langfuse.com/api/mcp"
}
}
}Tools
submitFeedback
Submit explicit user-approved feedback to the Langfuse team. Before calling, ask permission and show the exact payload. If the user wants a reply, ask them to include their email address in the feedback text; only use an address they explicitly provide and show it in the exact payload preview. Do not include secrets, credentials, customer/project data, trace payloads, or unrelated context; the only contact detail to include is an explicitly provided reply email.
Input schema and generated requestExpandCollapse
Input schema
{
"type": "object",
"properties": {
"targetType": {
"type": "string",
"enum": [
"skill",
"mcp-tool",
"cli",
"docs",
"public-api",
"other"
],
"description": "Category of the thing the feedback is about."
},
"target": {
"type": "string",
"minLength": 1,
"maxLength": 200,
"description": "The specific instance within targetType: the skill name, MCP tool name, CLI command, API endpoint path, or docs page path (e.g. 'queryMetrics', '/docs/mcp'). An identifier, not a sentence."
},
"feedback": {
"type": "string",
"minLength": 1,
"maxLength": 3000
},
"goal": {
"type": "string",
"minLength": 1,
"maxLength": 1500
},
"referenceUrl": {
"type": "string",
"format": "uri",
"maxLength": 2048
}
},
"required": [
"targetType",
"target",
"feedback"
],
"additionalProperties": false,
"$schema": "http://json-schema.org/draft-07/schema#"
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "submitFeedback",
"arguments": {
"feedback": "string",
"target": "string",
"targetType": "skill",
"goal": "string",
"referenceUrl": "https://example.com"
}
}
}searchLangfuseDocs
Semantic search (RAG) over the Langfuse documentation. Use this whenever the user asks a broader question that cannot be answered by a specific single page. Returns a concise answer synthesized from relevant docs. The raw provider response is included in _meta. Prefer this before guessing. If a specific page is needed call getLangfuseDocsPage first.
Input schema and generated requestExpandCollapse
Input schema
{
"type": "object",
"properties": {
"query": {
"type": "string",
"description": "The user's question in natural language. Include helpful context like SDK/language (e.g., Python v3, JS v4), self-hosted vs cloud, and short error messages (trim long stack traces). Keep under ~600 characters."
}
},
"required": [
"query"
],
"additionalProperties": false,
"$schema": "http://json-schema.org/draft-07/schema#"
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "searchLangfuseDocs",
"arguments": {
"query": "string"
}
}
}getLangfuseDocsPage
Fetch the raw Markdown for a single Langfuse docs page. Accepts a docs path (e.g., /docs/observability/overview) or a full https://langfuse.com URL. Returns the exact Markdown (may include front matter). Use when you need a specific page content (Integration, Features, API, etc.) or code samples. Prefer searchLangfuseDocs for broader questions where there is not one specific page about it. Changelog pages (/changelog/...) are historical release notes: use them only to confirm that a feature exists or when it shipped, not as an implementation reference. Their code samples reflect the SDK/API at release time and may be outdated, so for implementation follow the current docs and the API/SDK reference instead.
Input schema and generated requestExpandCollapse
Input schema
{
"type": "object",
"properties": {
"pathOrUrl": {
"type": "string",
"description": "Docs path starting with \"/\" (e.g., /docs/observability/overview) or a full URL on https://langfuse.com. Do not include anchors (#...) or queries (?foo=bar) — they will be ignored."
}
},
"required": [
"pathOrUrl"
],
"additionalProperties": false,
"$schema": "http://json-schema.org/draft-07/schema#"
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getLangfuseDocsPage",
"arguments": {
"pathOrUrl": "string"
}
}
}getLangfuseOverview
Get a high-level, machine-readable index by downloading https://langfuse.com/llms.txt. Use this at the start of a session when needed to discover key docs endpoints or to seed follow-up calls to searchLangfuseDocs or getLangfuseDocsPage. Returns the plain text contents of llms.txt. Avoid repeated calls within the same session.
Input schema and generated requestExpandCollapse
Input schema
{
"type": "object",
"properties": {},
"additionalProperties": false,
"$schema": "http://json-schema.org/draft-07/schema#"
}Generated request
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getLangfuseOverview",
"arguments": {}
}
}