> ## Documentation Index > Fetch the complete documentation index at: https://docs.langchain.com/llms.txt > Use this file to discover all available pages before exploring further. # Query Single Thread Stats > **Alpha:** The request and response contract may change; Compute aggregate stats for a single thread (turn count, latency percentiles, token/cost sums, and detail breakdowns) within a project. ## OpenAPI ````yaml /langsmith/langsmith-platform-openapi.json get /v2/threads/{thread_id}/stats openapi: 3.1.0 info: title: LangSmith description: >+ The LangSmith API is used to programmatically create and manage LangSmith resources. ## Host https://api.smith.langchain.com ## Authentication To authenticate with the LangSmith API, set the `X-Api-Key` header to a valid [LangSmith API key](https://docs.langchain.com/langsmith/create-account-api-key#create-an-api-key). version: 0.1.0 servers: - url: / security: [] tags: - name: run x-group: Tracing - name: runs x-group: Tracing - name: sessions x-group: Tracing - name: tracer-sessions x-group: Tracing - name: datasets x-group: Datasets - name: examples x-group: Datasets - name: evaluators x-group: Evaluation - name: experiment-view-overrides x-group: Evaluation - name: experiments x-group: Evaluation - name: annotation-queues x-group: Feedback & Annotation - name: annotation_queues x-group: Feedback & Annotation - name: feedback x-group: Feedback & Annotation - name: feedback-configs x-group: Feedback & Annotation - name: alert_rules x-group: Monitoring - name: bulk-exports x-group: Monitoring - name: charts x-group: Monitoring - name: commits x-group: Prompts & Playground - name: directories x-group: Prompts & Playground - name: hub_environments x-group: Prompts & Playground - name: playground-settings x-group: Prompts & Playground - name: prompt-webhooks x-group: Prompts & Playground - name: prompts x-group: Prompts & Playground - name: tag-transitions x-group: Prompts & Playground - name: comments x-group: Prompt Hub - name: likes x-group: Prompt Hub - name: optimization-jobs x-group: Prompt Hub - name: ownerships x-group: Prompt Hub - name: repos x-group: Prompt Hub - name: settings x-group: Prompt Hub - name: tags x-group: Prompt Hub - name: integrations x-group: Integrations & Tools - name: mcp x-group: Integrations & Tools - name: mcp_vendors x-group: Integrations & Tools - name: oauth x-group: Integrations & Tools - name: tools x-group: Integrations & Tools - name: gateway-policies x-group: LLM Gateway - name: sandboxes x-group: Sandboxes - name: issues x-group: Issues - name: issues-agent x-group: Issues - name: Organizations x-group: Administration - name: SCIM Tokens x-group: Administration - name: TTL Settings x-group: Administration - name: access_policies x-group: Administration - name: api-key x-group: Administration - name: audit-logs x-group: Administration - name: auth x-group: Administration - name: aws_marketplace x-group: Administration - name: data_planes x-group: Administration - name: me x-group: Administration - name: orgs x-group: Administration - name: service-accounts x-group: Administration - name: tenant x-group: Administration - name: ttl-settings x-group: Administration - name: usage-limits x-group: Administration - name: workspaces x-group: Administration - name: ace x-group: System - name: backfills x-group: System - name: features x-group: System - name: info x-group: System - name: model-price-map x-group: System - name: public x-group: System - name: threads x-group: System - name: agents x-hidden: true - name: beacon x-hidden: true - name: engine-trial - name: fleet - name: fleet auth x-hidden: true - name: fleet credentials x-hidden: true - name: fleet github-app x-hidden: true - name: fleet integrations x-hidden: true - name: fleet mcp x-hidden: true - name: fleet threads x-hidden: true - name: fleet trigger-templates x-hidden: true - name: fleet triggers x-hidden: true - name: fleet usage x-hidden: true - name: fleet_webhooks x-hidden: true - name: health - name: internal x-hidden: true - name: metrics x-hidden: true - name: nps x-hidden: true - name: sandboxes-internal x-hidden: true - name: skills x-hidden: true paths: /v2/threads/{thread_id}/stats: get: tags: - threads summary: Query Single Thread Stats description: >- **Alpha:** The request and response contract may change; Compute aggregate stats for a single thread (turn count, latency percentiles, token/cost sums, and detail breakdowns) within a project. parameters: - description: Thread ID name: thread_id in: path required: true schema: type: string - example: - TURNS - LATENCY_P50 description: >- `selects` lists which aggregate stats to compute and return (repeatable query parameter). At least one value is required. Accepts any value of `SingleThreadStatsSelectField`. name: selects in: query style: form explode: true schema: items: enum: - TURNS - FIRST_START_TIME - LAST_START_TIME - LAST_END_TIME - LATENCY_P50 - LATENCY_P99 - PROMPT_TOKENS - PROMPT_COST - COMPLETION_TOKENS - COMPLETION_COST - TOTAL_TOKENS - TOTAL_COST - PROMPT_TOKEN_DETAILS - COMPLETION_TOKEN_DETAILS - PROMPT_COST_DETAILS - COMPLETION_COST_DETAILS type: string type: array title: Selects - description: '`session_id` is the tracing project (session) UUID (required).' name: session_id in: query required: true schema: type: string format: uuid title: Session Id responses: '200': description: aggregate stats for the thread content: application/json: schema: $ref: >- #/components/schemas/threads.QuerySingleThreadStatsResponseBody '400': description: bad request (missing or invalid query parameters) content: application/json: schema: $ref: '#/components/schemas/shared.ProblemDetails' '401': description: missing or invalid authentication content: application/json: schema: $ref: '#/components/schemas/shared.ProblemDetails' '403': description: forbidden (insufficient permission) content: application/json: schema: $ref: '#/components/schemas/shared.ProblemDetails' '404': description: session not found content: application/json: schema: $ref: '#/components/schemas/shared.ProblemDetails' '422': description: unprocessable entity (e.g. invalid project UUID) content: application/json: schema: $ref: '#/components/schemas/shared.ProblemDetails' '500': description: internal server error content: application/json: schema: $ref: '#/components/schemas/shared.ProblemDetails' '503': description: service unavailable content: application/json: schema: $ref: '#/components/schemas/shared.ProblemDetails' '504': description: gateway timeout or deadline exceeded content: application/json: schema: $ref: '#/components/schemas/shared.ProblemDetails' security: - API Key: [] Tenant ID: [] - Bearer Auth: [] Tenant ID: [] components: schemas: threads.QuerySingleThreadStatsResponseBody: type: object properties: completion_cost: description: >- `completion_cost` is the sum of per-trace completion costs across the thread, in USD. Populated when `COMPLETION_COST` is selected. type: number completion_cost_details: description: >- `completion_cost_details` is the per-sub-category sum of completion cost details across the thread. Populated when `COMPLETION_COST_DETAILS` is selected. allOf: - $ref: '#/components/schemas/query.RunCompletionCostDetails' completion_token_details: description: >- `completion_token_details` is the per-sub-category sum of completion token details across the thread. Populated when `COMPLETION_TOKEN_DETAILS` is selected. allOf: - $ref: '#/components/schemas/query.RunCompletionTokenDetails' completion_tokens: description: >- `completion_tokens` is the sum of per-trace completion token counts across the thread. Populated when `COMPLETION_TOKENS` is selected. type: integer first_start_time: description: >- `first_start_time` is the earliest trace start time in the thread (RFC3339). Populated when `FIRST_START_TIME` is selected. type: string format: date-time last_end_time: description: >- `last_end_time` is the latest trace end time in the thread (RFC3339). Populated when `LAST_END_TIME` is selected. type: string format: date-time last_start_time: description: >- `last_start_time` is the latest trace start time in the thread (RFC3339). Populated when `LAST_START_TIME` is selected. type: string format: date-time latency_p50_seconds: description: >- `latency_p50_seconds` is the approximate p50 of trace latency across the thread, in seconds. Populated when `LATENCY_P50` is selected. type: number latency_p99_seconds: description: >- `latency_p99_seconds` is the approximate p99 of trace latency across the thread, in seconds. Populated when `LATENCY_P99` is selected. type: number prompt_cost: description: >- `prompt_cost` is the sum of per-trace prompt costs across the thread, in USD. Populated when `PROMPT_COST` is selected. type: number prompt_cost_details: description: >- `prompt_cost_details` is the per-sub-category sum of prompt cost details across the thread. Populated when `PROMPT_COST_DETAILS` is selected. allOf: - $ref: '#/components/schemas/query.RunPromptCostDetails' prompt_token_details: description: >- `prompt_token_details` is the per-sub-category sum of prompt token details across the thread. Populated when `PROMPT_TOKEN_DETAILS` is selected. allOf: - $ref: '#/components/schemas/query.RunPromptTokenDetails' prompt_tokens: description: >- `prompt_tokens` is the sum of per-trace prompt token counts across the thread. Populated when `PROMPT_TOKENS` is selected. type: integer total_cost: description: >- `total_cost` is the sum of per-trace total costs across the thread, in USD. Populated when `TOTAL_COST` is selected. type: number total_tokens: description: >- `total_tokens` is the sum of per-trace total token counts across the thread. Populated when `TOTAL_TOKENS` is selected. type: integer turns: description: >- `turns` is the number of distinct traces (turns) in the thread. Populated when `TURNS` is selected. type: integer shared.ProblemDetails: description: RFC 7807 problem details returned on V2 API errors. type: object properties: detail: type: string instance: type: string remedy: description: Remedy is a LangSmith extension for user-recoverable errors. type: string status: type: integer title: type: string type: type: string query.RunCompletionCostDetails: type: object properties: raw: description: '`raw` maps each category name to its estimated USD cost.' type: object additionalProperties: type: number format: float64 query.RunCompletionTokenDetails: type: object properties: raw: description: '`raw` maps each category name to its completion-token count.' type: object additionalProperties: type: integer format: int64 query.RunPromptCostDetails: type: object properties: raw: description: '`raw` maps each category name to its estimated USD cost.' type: object additionalProperties: type: number format: float64 query.RunPromptTokenDetails: type: object properties: raw: description: '`raw` maps each category name to its prompt-token count.' type: object additionalProperties: type: integer format: int64 securitySchemes: API Key: type: apiKey in: header name: X-API-Key Tenant ID: type: apiKey in: header name: X-Tenant-Id Bearer Auth: type: http description: >- Bearer tokens are used to authenticate from the UI. Must also specify x-tenant-id or x-organization-id (for org scoped apis). scheme: bearer ````