runs

Query traces

Changed on

Returns a paginated list of traces (root runs) for a single tracing project. Each item carries the trace's root run plus optional trace-wide aggregates (total_tokens, total_cost, first_token_time) under trace_aggregates, so clients never have to merge by trace_id.

Traces are scanned within a start_time window: min_start_time defaults to 24 hours before the request, max_start_time defaults to the request time. Set either explicitly to widen or narrow the window.

Supports filters (trace_filter, tree_filter), cursor pagination (cursor), and field projection (selects).

When ai_search is set, Accept: text/event-stream is required; requests without it return 406. AI search is unavailable on deployments that route queries to the v1 backend and returns 501 there.

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

post/api/v2/traces/query

Request

  • Base URL
    https://api.smith.langchain.com
  • URL
    https://api.smith.langchain.com/api/v2/traces/query
  • Auth
    • API key in header X-API-Key and API key in header X-Tenant-Id
    • or HTTP bearer and API key in header X-Tenant-Id

Headers

Acceptstring

application/json, or text/event-stream (required when ai_search is set)

Content-Typestring

application/json (required for JSON body)

Request body

ai_searchstring

ai_search is a plain-language criterion evaluated against the messages from the agent trajectory scoped to the trace. AND-ed with the ordinary filters. Requires semantic filtering enabled for the deployment. Must contain nonempty text of at most 2000 UTF-8 bytes.

cursorstring

cursor is the opaque string returned in a previous response's next_cursor.

max_feedback_modified_atstring date-time

max_feedback_modified_at is the exclusive upper bound (RFC3339) on feedback modified_at, applied to the feedback conditions in trace_filter or tree_filter (for example eq(feedback_key, "correctness")). Requires at least one feedback condition. Root runs must still fall within the start_time window.

max_start_timestring date-time

max_start_time is the exclusive upper bound for the root-run start time scan (RFC3339). Defaults to the request time when omitted.

min_feedback_modified_atstring date-time

min_feedback_modified_at is the inclusive lower bound (RFC3339) on feedback modified_at, applied to the feedback conditions in trace_filter or tree_filter (for example eq(feedback_key, "correctness")). Requires at least one feedback condition. Root runs must still fall within the start_time window.

min_start_timestring date-time

min_start_time is the inclusive lower bound for the root-run start time scan (RFC3339). Defaults to 24 hours before the request when omitted.

page_sizeinteger

page_size is the maximum number of traces to return per page. Defaults to 20; must be between 1 and 100 when set.

project_idstring uuid

project_id is the UUID of the tracing project that owns the traces. Required.

selectsQueryRunSelectField[]

selects lists which properties to include on each returned trace. Properties listed here are routed to the appropriate sub-object on each item: total_tokens, total_cost, and first_token_time appear under trace_aggregates; everything else appears under root_run. If omitted, only id is returned on root_run.

trace_filterstring

trace_filter narrows results to traces whose root run matches this LangSmith filter expression. This filter targets root runs only — is_root = true is implied. See https://docs.langchain.com/langsmith/trace-query-syntax#filter-query-language for syntax.

trace_idsstring[]

trace_ids is an optional fast-path restriction to a known set of trace UUIDs. Equivalent in result to including each UUID in a trace_filter, but more efficient at scale.

tree_filterstring

tree_filter narrows results to traces containing at least one run anywhere in the run tree (root or descendant) that matches this LangSmith filter expression.

Example request

{
  "ai_search": "A run that contains a billing dispute",
  "max_feedback_modified_at": "2024-12-31T23:59:59Z",
  "max_start_time": "2024-12-31T23:59:59Z",
  "min_feedback_modified_at": "2024-01-01T00:00:00Z",
  "min_start_time": "2024-01-01T00:00:00Z",
  "page_size": 20,
  "project_id": "018e4c7e-a9fb-7ef0-a5b6-6ea3a82e9327",
  "selects": [
    "ID",
    "NAME",
    "START_TIME",
    "STATUS",
    "TOTAL_TOKENS",
    "TOTAL_COST",
    "FIRST_TOKEN_TIME"
  ],
  "trace_filter": "eq(status, \"error\")",
  "tree_filter": "has(tags, \"production\")"
}

Response

OK

next_cursorstring

next_cursor is the opaque cursor for the next page. Null on the final page.

Example response

{
  "items": [
    {
      "root_run": {
        "app_path": "/app/chains/chat.py:invoke",
        "completion_cost": 0.0003,
        "completion_tokens": 150,
        "dotted_order": "20240115T103000000000Z018e4c7ea9fb7ef0a5b66ea3a82e9327.",
        "end_time": "2024-01-15T10:30:01.500Z",
        "error": "context deadline exceeded",
        "events": [
          {
            "name": "new_token",
            "time": "2024-01-15T10:30:00.312Z"
          }
        ],
        "first_token_time": "2024-01-15T10:30:00.312Z",
        "id": "018e4c7e-a9fb-7ef0-a5b6-6ea3a82e9327",
        "is_in_dataset": true,
        "is_root": true,
        "last_queued_at": "2024-01-15T10:31:00Z",
        "latency_seconds": 1.523,
        "ls_user_id": "f6a7b8c9-d0e1-4f2a-3b4c-5d6e7f8a9b0c",
        "name": "ChatOpenAI",
        "parent_run_ids": [
          "018e4c7e-a9fb-7ef0-a5b6-6ea3a82e9327",
          "a1b2c3d4-e5f6-4a5b-8c9d-0e1f2a3b4c5d"
        ],
        "price_model_id": "e5f6a7b8-c9d0-4e1f-2a3b-4c5d6e7f8a9b",
        "project_id": "018e4c7e-a9fb-7ef0-a5b6-6ea3a82e9327",
        "prompt_cost": 0.0002,
        "prompt_tokens": 200,
        "reference_dataset_id": "c3d4e5f6-a7b8-4c5d-0e1f-2a3b4c5d6e7f",
        "reference_example_id": "b2c3d4e5-f6a7-4b5c-9d0e-1f2a3b4c5d6e",
        "share_url": "https://smith.langchain.com/public/4f7a1b2c-8d9e-4a0b-9c1d-2e3f4a5b6c7d/r",
        "start_time": "2024-01-15T10:30:00.000Z",
        "tags": [
          "production",
          "gpt-4"
        ],
        "thread_id": "d4e5f6a7-b8c9-4d5e-1f2a-3b4c5d6e7f8a",
        "total_cost": 0.000525,
        "total_tokens": 350,
        "trace_id": "018e4c7e-a9fb-7ef0-a5b6-6ea3a82e9327"
      }
    }
  ]
}

Changes