---
title: "Get a single run"
method: GET
path: "/api/v2/runs/{run_id}"
tags: ["runs"]
---

# Get a single run

`GET /api/v2/runs/{run_id}`

## Request

- Base URL: `https://api.smith.langchain.com`
- URL: `https://api.smith.langchain.com/api/v2/runs/{run_id}`
- Auth: one of:
  - API key in header `X-API-Key` and API key in header `X-Tenant-Id`
  - HTTP bearer and API key in header `X-Tenant-Id`

Returns one run by ID for the given session. Use the `selects` query parameter (repeatable) to select fields to return.

Self-hosted deployments require LangSmith `v0.16` or later.

## Path parameters

- `run_id` string, uuid, required

## Query parameters

- `project_id` string, uuid, required
- `selects` string[]
- `start_time` string, date-time

## Headers

- `Accept` string

## Response `200`

OK

- QueryRunResponse
  - `app_path` string: `app_path` identifies the application code location that produced this run, if recorded.
  - `attachments` QueryRunAttachmentURLs
  - `completion_cost` number: `completion_cost` is estimated USD cost for the completion.
  - `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 completion-side token count.
  - `dotted_order` string: `dotted_order` is the hierarchical ordering key for trace trees.
  - `end_time` string, date-time: `end_time` is when the run ended (RFC3339 date-time). JSON null if the run has not finished yet.
  - `error` string: `error` is the error message when `status` indicates failure.
  - `error_preview` string: `error_preview` is a truncated plain-text error snippet.
  - `events` QueryRunEvent[]: `events` is the ordered list of run events (for example streaming tokens).
    - `kwargs` object: `kwargs` is the event payload — an opaque JSON object whose shape depends on `name` and on the emitting SDK. For example LangChain emits `{"token": {...}}` for `new_token` events, tool-call start/end details for tool events, and arbitrary user-defined payloads for custom events. Clients should treat `kwargs` as untyped JSON: do not assume specific keys exist for a given `name`, and tolerate additional unknown keys appearing over time.
    - `name` string: `name` is the event kind. Common values emitted by the LangChain/LangSmith tracer SDKs include `"start"`, `"end"`, and `"new_token"`, but applications may emit arbitrary strings for their own instrumentation.
    - `time` string, date-time: `time` is when the event occurred (RFC3339 date-time with millisecond precision).
  - `extra` object: `extra` is additional runtime JSON attached to the run.
  - `feedback_stats` QueryRunFeedbackStats
  - `first_token_time` string, date-time: `first_token_time` is when the first output token was produced (RFC3339 date-time), when recorded for streamed runs.
  - `id` string, uuid: `id` is this run's UUID.
  - `inputs` object: `inputs` is the run input payload (arbitrary JSON object).
  - `inputs_preview` string: `inputs_preview` is a truncated plain-text preview of inputs.
  - `is_in_dataset` boolean: `is_in_dataset` is true when this run is linked to a dataset example.
  - `is_root` boolean: `is_root` is true when this run has no parent (it is the trace root).
  - `last_queued_at` string, date-time: `last_queued_at` is the most recent time this run was added to an annotation queue.
  - `latency_seconds` number: `latency_seconds` is wall-clock duration from start to end in seconds.
  - `ls_user_id` string, uuid: `ls_user_id` identifies the LangSmith user whose credential traced the run. It is absent for runs traced with a service-account API key, which has no associated user.
  - `manifest` object: `manifest` is the serialized configuration of the traced component (for example the model parameters, prompt template, or pipeline definition), when recorded.
  - `metadata` object: `metadata` is arbitrary user-defined JSON metadata.
  - `name` string: `name` is a human-readable label for the run (for example the model name, function name, or step name chosen when the run was traced).
  - `outputs` object: `outputs` is the run output payload (arbitrary JSON object).
  - `outputs_preview` string: `outputs_preview` is a truncated plain-text preview of outputs.
  - `parent_run_ids` string[]: `parent_run_ids` lists ancestor run UUIDs from the trace root down to the direct parent.
  - `price_model_id` string, uuid: `price_model_id` identifies the pricing model UUID used for cost estimates, when recorded.
  - `project_id` string, uuid: `project_id` is the tracing project UUID this run was logged to.
  - `prompt_cost` number: `prompt_cost` is estimated USD cost for the prompt.
  - `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 prompt-side token count.
  - `query_metadata` object, nullable: `query_metadata` describes this query result, including `sem_filter_score` when a semantic filter is used. Returned automatically by run queries, or null when unavailable.
  - `reference_dataset_id` string, uuid: `reference_dataset_id` is the dataset UUID for the reference example, if any.
  - `reference_example_id` string, uuid: `reference_example_id` is the dataset example UUID this run was compared against, if any.
  - `run_type` 'TOOL' | 'CHAIN' | 'LLM' | 'RETRIEVER' | 'EMBEDDING' | 'PROMPT' | 'PARSER'
  - `share_url` string: `share_url` is the fully-qualified URL of this run's public view, rooted at the deployment's LangSmith app origin (for example `https://smith.langchain.com/public/4f7a1b2c-8d9e-4a0b-9c1d-2e3f4a5b6c7d/r`). It is returned only when `SHARE_URL` is included in `selects`, and only when the run has been explicitly shared; the URL remains stable until the run is unshared. Anyone with this URL can view the run anonymously, so treat it as a secret and do not log it.
  - `start_time` string, date-time: `start_time` is when the run started (RFC3339 date-time).
  - `status` 'SUCCESS' | 'ERROR' | 'PENDING'
  - `tags` string[]: `tags` lists user-defined tags on this run.
  - `thread_evaluation_time` string, date-time: `thread_evaluation_time` is thread-level evaluation timing (RFC3339 date-time), when recorded.
  - `thread_id` string, uuid: `thread_id` is the conversation thread UUID this run belongs to, if any.
  - `total_cost` number: `total_cost` is total estimated USD cost (prompt plus completion).
  - `total_tokens` integer: `total_tokens` is prompt plus completion tokens.
  - `trace_id` string, uuid: `trace_id` is the root trace UUID; for a root run it matches `id`.

## Other responses

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

## Changes

- **2026-10-16** `1a8ee9358d81`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/langchain-ai/apis/langsmith/changes/api/v2/runs/:run_id/get.md)

---

[API](https://skmtc.dev/langchain-ai/apis/langsmith.md) - [All operations](https://skmtc.dev/langchain-ai/apis/langsmith/llms.txt) - [OpenAPI document](https://skmtc.dev/langchain-ai/apis/langsmith/revisions/7a01c01f75e8?raw)