---
title: "Query Single Thread Stats"
method: GET
path: "/v2/threads/{thread_id}/stats"
tags: ["threads"]
---

# Query Single Thread Stats

`GET /v2/threads/{thread_id}/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.

## Path parameters

- `thread_id` string, required

## Query parameters

- `selects` string[]
- `session_id` string, uuid, required

## Response `200`

aggregate stats for the thread

- ThreadsQuerySingleThreadStatsResponseBody
  - `completion_cost` number — `completion_cost` is the sum of per-trace completion costs across the thread, in USD. Populated when `COMPLETION_COST` is selected.
  - `completion_cost_details` QueryRunCompletionCostDetails
    - `raw` object — `raw` maps each category name to its estimated USD cost.
  - `completion_token_details` QueryRunCompletionTokenDetails
    - `raw` object — `raw` maps each category name to its completion-token count.
  - `completion_tokens` integer — `completion_tokens` is the sum of per-trace completion token counts across the thread. Populated when `COMPLETION_TOKENS` is selected.
  - `first_start_time` string, date-time — `first_start_time` is the earliest trace start time in the thread (RFC3339). Populated when `FIRST_START_TIME` is selected.
  - `last_end_time` string, date-time — `last_end_time` is the latest trace end time in the thread (RFC3339). Populated when `LAST_END_TIME` is selected.
  - `last_start_time` string, date-time — `last_start_time` is the latest trace start time in the thread (RFC3339). Populated when `LAST_START_TIME` is selected.
  - `latency_p50_seconds` number — `latency_p50_seconds` is the approximate p50 of trace latency across the thread, in seconds. Populated when `LATENCY_P50` is selected.
  - `latency_p99_seconds` number — `latency_p99_seconds` is the approximate p99 of trace latency across the thread, in seconds. Populated when `LATENCY_P99` is selected.
  - `prompt_cost` number — `prompt_cost` is the sum of per-trace prompt costs across the thread, in USD. Populated when `PROMPT_COST` is selected.
  - `prompt_cost_details` QueryRunPromptCostDetails
    - `raw` object — `raw` maps each category name to its estimated USD cost.
  - `prompt_token_details` QueryRunPromptTokenDetails
    - `raw` object — `raw` maps each category name to its prompt-token count.
  - `prompt_tokens` integer — `prompt_tokens` is the sum of per-trace prompt token counts across the thread. Populated when `PROMPT_TOKENS` is selected.
  - `total_cost` number — `total_cost` is the sum of per-trace total costs across the thread, in USD. Populated when `TOTAL_COST` is selected.
  - `total_tokens` integer — `total_tokens` is the sum of per-trace total token counts across the thread. Populated when `TOTAL_TOKENS` is selected.
  - `turns` integer — `turns` is the number of distinct traces (turns) in the thread. Populated when `TURNS` is selected.

## Other responses

- `400` — bad request (missing or invalid query parameters)
- `401` — missing or invalid authentication
- `403` — forbidden (insufficient permission)
- `404` — session not found
- `422` — unprocessable entity (e.g. invalid project UUID)
- `500` — internal server error
- `503` — service unavailable
- `504` — gateway timeout or deadline exceeded

---

[API](https://skmtc.net/langchain-ai/apis/langsmith.md) · [All operations](https://skmtc.net/langchain-ai/apis/langsmith/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/langchain-ai/langsmith/revisions/a0acb3a6a101/schema)