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

# Get a presigned upload URL

> Returns a presigned S3 PUT URL and the full S3 key for uploading a single file into the session's prefix. The caller should PUT the file bytes directly to `uploadUrl`, then call `/sessions/{sessionId}/files/sync-to-sandbox` with the returned `key`. Requires write access to the session.



## OpenAPI

````yaml /openapi/openapi.json post /sessions/{sessionId}/files/upload-sign
openapi: 3.1.0
info:
  title: IMP REST API
  version: 1.0.0
  description: >-
    REST endpoints of the IMP backend. GraphQL covers entity CRUD; REST covers
    agent runs, media, files, and system utilities. All requests require
    authentication unless the agent is public.
servers:
  - url: '{baseUrl}'
    variables:
      baseUrl:
        default: http://localhost:9001
        description: >-
          Base URL of your IMP backend. Self-hosted deployments typically run on
          port 9001.
security:
  - apiKey: []
  - bearer: []
tags:
  - name: Agents
    description: Endpoints for running, compacting, and querying agent instances.
  - name: Sessions
    description: Endpoints for managing files attached to agent sessions.
  - name: Media
    description: Transcription, speech synthesis, and image generation.
  - name: System
    description: Platform health and configuration utilities.
  - name: Budgets
    description: >-
      LiteLLM tag-budget management for users, roles, teams, projects, agents,
      and routines. Access requires `super_admin` or a role with
      `budget_management` write scope.
  - name: Skills
    description: >-
      Skills are versioned bundles of files (markdown, scripts, assets) mounted
      into the agent sandbox. These endpoints manage the skill registry and
      individual skill files.
  - name: Uploads
    description: >-
      Uppy-compatible S3 companion routes for single-part and multipart file
      uploads. Accept the standard API key. The `internal-key` header (set to
      `INTERNAL_SECRET`) is accepted only on `/s3/delete`, `/s3/download`,
      `/s3/list`, and `/s3/object` — it does **not** work on `/s3/sign` or the
      `/s3/multipart` routes.
  - name: Compliance
    description: >-
      GDPR / DSGVO operator endpoints for data-subject access (export) and
      erasure. Both require `super_admin`.
  - name: Artifacts
    description: >-
      Shareable artifact links — create, list, and revoke share links for files
      stored in S3.
paths:
  /sessions/{sessionId}/files/upload-sign:
    post:
      tags:
        - Sessions
      summary: Get a presigned upload URL
      description: >-
        Returns a presigned S3 PUT URL and the full S3 key for uploading a
        single file into the session's prefix. The caller should PUT the file
        bytes directly to `uploadUrl`, then call
        `/sessions/{sessionId}/files/sync-to-sandbox` with the returned `key`.
        Requires write access to the session.
      operationId: signSessionFileUpload
      parameters:
        - name: sessionId
          in: path
          required: true
          description: Agent session ID (UUID).
          schema:
            type: string
            format: uuid
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
                - filename
                - contentType
              properties:
                filename:
                  type: string
                  description: Desired filename. Path separators and `..` are rejected.
                contentType:
                  type: string
                  description: MIME type for the S3 object (e.g. `application/pdf`).
      responses:
        '200':
          description: Presigned upload URL and the resulting S3 key.
          content:
            application/json:
              schema:
                type: object
                properties:
                  uploadUrl:
                    type: string
                    description: Presigned S3 PUT URL.
                  key:
                    type: string
                    description: Full S3 object key to pass to sync-to-sandbox.
                required:
                  - uploadUrl
                  - key
        '400':
          description: >-
            Missing `filename` or `contentType`, or filename failed safety
            validation.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '401':
          description: Authentication failed or caller lacks write access to the session.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
components:
  schemas:
    Error:
      type: object
      properties:
        detail:
          type: string
          description: Human-readable error message.
        message:
          type: string
          description: Human-readable error message (alternate key used on some endpoints).
  securitySchemes:
    apiKey:
      type: apiKey
      in: header
      name: x-api-key
      description: >-
        Organisation API key. Format: `sk_<secret>/<keyname>` — the secret
        portion, a literal slash, and the human-readable key name. The header
        `exulu-api-key` is accepted as an alias. A `Bearer ` prefix is tolerated
        and stripped. Keys with an agent scope are only valid for the scoped
        agent instance.
    bearer:
      type: http
      scheme: bearer
      bearerFormat: JWT
      description: >-
        NextAuth session JWT (HS256, signed with `NEXTAUTH_SECRET`). This is the
        token the IMP frontend uses automatically.

````