---
title: "Get the LangSmith UI URL for a run"
method: GET
path: "/api/v2/runs/{run_id}/url"
tags: ["runs"]
---

# Get the LangSmith UI URL for a run

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

## Request

- Base URL: `https://api.smith.langchain.com`
- URL: `https://api.smith.langchain.com/api/v2/runs/{run_id}/url`
- 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 the URL to view a specific run in the LangSmith UI. The caller must supply the
run's project_id and trace_id as query parameters; start_time is optional.

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

## Path parameters

- `run_id` string, uuid, required

## Query parameters

- `project_id` string, required
- `trace_id` string, required
- `start_time` string

## Response `200`

OK

- QueryRunURLResponse
  - `url` string

## Other responses

- `400`: missing or invalid query parameters
- `401`: missing or invalid authentication
- `403`: forbidden
- `404`: project not found or does not belong to this workspace

## Changes

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

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