> ## Documentation Index
> Fetch the complete documentation index at: https://langwatch.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Get trace details

> Get a single trace by ID.



## OpenAPI

````yaml GET /api/traces/{traceId}
openapi: 3.1.0
info:
  title: LangWatch API
  version: 1.0.0
  description: LangWatch openapi spec
servers:
  - url: https://app.langwatch.ai
security:
  - project_api_key: []
paths:
  /api/traces/{traceId}:
    get:
      description: Get a single trace by ID.
      operationId: getApiTracesByTraceId
      parameters:
        - name: traceId
          in: path
          description: >-
            The trace ID — either the full 32-char ID or a unique prefix (≥ 8
            chars). Prefix lookup is scoped to the authenticated project.
          required: true
          schema:
            type: string
        - name: format
          in: query
          description: >-
            Output format: 'digest' (default, AI-readable) or 'json' (full raw
            data)
          required: false
          schema:
            type: string
            enum:
              - digest
              - json
        - name: llmMode
          in: query
          description: 'Deprecated: use format=digest instead'
          required: false
          schema:
            type: string
            enum:
              - 'true'
              - 'false'
              - '1'
              - '0'
      responses:
        '200':
          description: Trace detail with spans, evaluations, and ASCII tree
          content:
            application/json:
              schema:
                type: object
                additionalProperties: true
        '400':
          description: Bad Request
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: string
                  message:
                    type: string
                required:
                  - error
        '401':
          description: Unauthorized
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: string
                  message:
                    type: string
                required:
                  - error
        '404':
          description: Trace not found
          content:
            application/json:
              schema:
                type: object
                properties:
                  message:
                    type: string
                required:
                  - message
        '409':
          description: Ambiguous trace ID prefix — the prefix matches more than one trace
          content:
            application/json:
              schema:
                type: object
                properties:
                  message:
                    type: string
                  candidateTraceIds:
                    type: array
                    items:
                      type: string
                required:
                  - message
                  - candidateTraceIds
        '422':
          description: Unprocessable Entity
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: string
                  message:
                    type: string
                required:
                  - error
        '500':
          description: Internal Server Error
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: string
                  message:
                    type: string
                required:
                  - error
components:
  securitySchemes:
    project_api_key:
      type: apiKey
      in: header
      name: X-Auth-Token
      description: >-
        Project API key for sending traces and accessing project-scoped
        resources. Format: sk-lw-... (no underscore). Obtain one by creating a
        project via the Admin API or the LangWatch UI.

````