Cognition Labs Sessions API

openapi: 3.0.3
info:
  title: Devin API (Cognition Labs) Attachments Sessions API
  description: The Devin API lets you create and drive Devin, Cognition's autonomous AI software engineer, programmatically. This document models the legacy v1 surface (api.devin.ai/v1, still live and documented, authenticated with apk_user_*/apk_* keys) in full - sessions, messages, attachments, knowledge, playbooks, and secrets - plus representative endpoints from the current v3 organizations/enterprise surface (api.devin.ai/v3, authenticated with cog_ service-user or personal access tokens) and the v2/v3 consumption (ACU usage) endpoints. The v2/v3 enterprise surface has additional organization, member, and API-key management endpoints not exhaustively modeled here; see the humanURL/APIReference links in apis.yml for the full documented set. All endpoints are transcribed from Cognition's public documentation at https://docs.devin.ai and have not been exercised against production credentials, which require an active paid Devin plan or Enterprise contract.
  version: '1.0'
  contact:
    name: Cognition
    url: https://cognition.ai
  license:
    name: Proprietary
    url: https://docs.devin.ai/admin/security
servers:
- url: https://api.devin.ai/v1
  description: Legacy v1 API (apk_user_*/apk_* keys)
- url: https://api.devin.ai/v3
  description: Current v3 organizations/enterprise API (cog_ keys)
security:
- bearerAuth: []
tags:
- name: Sessions
  description: Create and manage Devin sessions (v1 legacy surface).
paths:
  /sessions:
    post:
      operationId: createSession
      tags:
      - Sessions
      summary: Create a new Devin session
      description: Creates a new Devin session from a natural-language prompt, optionally seeded with a playbook, snapshot, knowledge, secrets, tags, and a max ACU cap.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CreateSessionInput'
      responses:
        '200':
          description: The created (or, if idempotent and matched, existing) session.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CreateSessionResponse'
        '422':
          $ref: '#/components/responses/ValidationError'
    get:
      operationId: listSessions
      tags:
      - Sessions
      summary: List sessions
      description: Lists sessions for the organization, with optional filters.
      parameters:
      - name: limit
        in: query
        schema:
          type: integer
          default: 100
      - name: offset
        in: query
        schema:
          type: integer
          default: 0
      - name: skip
        in: query
        schema:
          type: integer
      - name: tags
        in: query
        description: Filter sessions by tag.
        schema:
          type: array
          items:
            type: string
        style: form
        explode: true
      - name: user_email
        in: query
        description: Filter sessions by the creator's email address.
        schema:
          type: string
      responses:
        '200':
          description: A page of sessions.
          content:
            application/json:
              schema:
                type: object
                properties:
                  sessions:
                    type: array
                    items:
                      $ref: '#/components/schemas/SessionSummary'
        '422':
          $ref: '#/components/responses/ValidationError'
  /sessions/{session_id}:
    parameters:
    - $ref: '#/components/parameters/SessionId'
    get:
      operationId: getSession
      tags:
      - Sessions
      summary: Retrieve session details
      description: Retrieves full status, message history, and structured output for a session.
      responses:
        '200':
          description: The requested session.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SessionDetail'
        '422':
          $ref: '#/components/responses/ValidationError'
    delete:
      operationId: terminateSession
      tags:
      - Sessions
      summary: Terminate a session
      description: Terminates a running session. The session must not already be in an exited state.
      responses:
        '200':
          description: Termination confirmation.
          content:
            application/json:
              schema:
                type: object
                properties:
                  detail:
                    type: string
        '422':
          $ref: '#/components/responses/ValidationError'
  /sessions/{session_id}/tags:
    parameters:
    - $ref: '#/components/parameters/SessionId'
    put:
      operationId: updateSessionTags
      tags:
      - Sessions
      summary: Update session tags
      description: Replaces the tag list on a session (maximum 50 tags).
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
              - tags
              properties:
                tags:
                  type: array
                  maxItems: 50
                  items:
                    type: string
      responses:
        '200':
          description: Confirmation.
          content:
            application/json:
              schema:
                type: object
                properties:
                  detail:
                    type: string
        '422':
          $ref: '#/components/responses/ValidationError'
components:
  schemas:
    SessionStatusEnum:
      type: string
      enum:
      - working
      - blocked
      - expired
      - finished
      - suspend_requested
      - suspend_requested_frontend
      - resume_requested
      - resume_requested_frontend
      - resumed
    SessionSummary:
      type: object
      required:
      - session_id
      - status
      - created_at
      - updated_at
      properties:
        session_id:
          type: string
        status:
          type: string
        status_enum:
          $ref: '#/components/schemas/SessionStatusEnum'
        created_at:
          type: string
          format: date-time
        updated_at:
          type: string
          format: date-time
        title:
          type: string
        requesting_user_email:
          type: string
        playbook_id:
          type: string
        snapshot_id:
          type: string
        tags:
          type: array
          items:
            type: string
        pull_request:
          type: object
          properties:
            url:
              type: string
        structured_output:
          type: object
          additionalProperties: true
    CreateSessionInput:
      type: object
      required:
      - prompt
      properties:
        prompt:
          type: string
          description: The task prompt for Devin to work on.
        title:
          type: string
          description: Custom session name; auto-generated if omitted.
        snapshot_id:
          type: string
        playbook_id:
          type: string
        knowledge_ids:
          type: array
          items:
            type: string
          nullable: true
          description: Null uses all knowledge; empty array uses none.
        secret_ids:
          type: array
          items:
            type: string
          nullable: true
          description: Null uses all secrets; empty array uses none.
        session_secrets:
          type: array
          items:
            type: object
            properties:
              key:
                type: string
              value:
                type: string
              sensitive:
                type: boolean
        structured_output_schema:
          type: object
          description: JSON Schema (Draft 7) for validating structured output. Max 64KB.
          additionalProperties: true
        tags:
          type: array
          maxItems: 50
          items:
            type: string
        max_acu_limit:
          type: integer
          description: Maximum ACU allowance for the session.
        idempotent:
          type: boolean
          default: false
        unlisted:
          type: boolean
          default: false
    ValidationErrorBody:
      type: object
      properties:
        detail:
          type: array
          items:
            type: object
            properties:
              loc:
                type: array
                items:
                  type: string
              msg:
                type: string
              type:
                type: string
    CreateSessionResponse:
      type: object
      required:
      - session_id
      - url
      properties:
        session_id:
          type: string
        url:
          type: string
        is_new_session:
          type: boolean
    SessionDetail:
      allOf:
      - $ref: '#/components/schemas/SessionSummary'
      - type: object
        properties:
          messages:
            type: array
            default: []
            items:
              type: object
              additionalProperties: true
  parameters:
    SessionId:
      name: session_id
      in: path
      required: true
      description: The unique identifier of the session.
      schema:
        type: string
  responses:
    ValidationError:
      description: The request payload failed validation.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ValidationErrorBody'
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: 'v1/v2 keys are prefixed apk_user_* (personal) or apk_* (service). The current v3 API uses service-user or personal access tokens prefixed cog_. Passed as `Authorization: Bearer YOUR_API_KEY`.'