Papercrate REST API
===================

Unless noted otherwise, endpoints below require a valid `Authorization: Bearer <token>` header.

Authentication
--------------
- POST /api/auth/login - Exchange username/password for an access token and refresh cookie (public). Returns the active tenant as `{ tenant: { id, slug } }`. When multiple tenants are available, the response contains an `access_token` (tenant-selector token) and tenant list instead.
- POST /api/auth/refresh - Rotate the refresh cookie and return a new access token (public, requires refresh cookie). Response also includes the current tenant `{ tenant: { id, slug } }`.
- POST /api/auth/logout - Revoke the caller's refresh tokens and clear the cookie.
- GET  /api/auth/me - Return the authenticated principal payload.

Health
------
- GET  /api/health - Lightweight liveness probe (no authentication required).

Documents
---------
- GET  /api/documents - List or search documents. Optional filters: `folder_id` (defaults to root when omitted), `include_deleted`, `include_descendants` (defaults to true unless explicitly set to `false` without filters), `query` (Quickwit full-text), `tags` (comma-separated tag UUIDs), and `correspondents` (comma-separated correspondent UUIDs). Each entry includes tags, correspondent assignments, and current version info.
- GET  /api/documents/check?checksum=<sha256> - Lightweight checksum preflight. Returns `exists=false` when no document with the supplied SHA-256 checksum is present; otherwise returns `exists=true` plus the current document metadata.
- POST /api/documents - Upload a document via multipart form-data. Required field: `file`. Optional fields: `title`, `folder_id`, JSON `metadata`, JSON array `tag_ids`, JSON array `correspondents` (each with `correspondent_id` and `role`), and `issued_at` (RFC3339). When `title` is supplied, the stored filename becomes `<title><original_extension>`. Include `skip_existing=true` to receive `204 No Content` instead of reusing a matching document.
- POST /api/documents/bulk/move - Move multiple documents to a target folder.
- POST /api/documents/bulk/tags - Add or remove tags across multiple documents.
- POST /api/documents/bulk/correspondents - Bulk correspondent actions. Default `action=add` replaces existing assignments for the provided roles before adding the supplied correspondents; `action=remove` drops the specified correspondent/role pairs.
- POST /api/documents/bulk/reanalyze - Queue re-analysis jobs for selected documents.
- GET  /api/documents/:id - Retrieve metadata and current version details for a document.
- PATCH /api/documents/:id - Update document metadata (currently title).
- DELETE /api/documents/:id - Soft-delete a document.
- GET  /api/documents/:id/download - Create a pre-signed download URL for the current version.
- PATCH /api/documents/:id/folder - Move a document to another folder.
- POST /api/documents/:id/tags - Assign one or more tags to a document.
- DELETE /api/documents/:id/tags/:tag_id - Remove a single tag from a document.
- POST /api/documents/:id/correspondents - Assign correspondents to roles (`assignments[]` with `correspondent_id` and `role`; optional `replace=true` overwrites existing assignments for those roles). Valid roles: `sender`, `receiver`, `other`.
- DELETE /api/documents/:id/correspondents/:correspondent_id - Remove a correspondent assignment (requires `role` query string).

Document Assets
---------------
- GET  /api/documents/:id/assets - List generated assets for the current version.
- POST /api/documents/:id/assets - Request (re)generation of document assets; accepts optional `force` query flag.
- GET  /api/assets/:asset_id - Fetch asset metadata plus a presigned URL for a range of objects (query params: `start` and `limit`, defaulting to the first object).

Downloads
---------
- GET  /download/:token - Follow a one-time download token; redirects to a pre-signed URL (public token required).

Folders
-------
- POST /api/folders - Create a folder (optionally under a parent).
- POST /api/folders/path - Ensure a nested folder path exists, creating missing segments.
- GET  /api/folders/:id - Fetch folder metadata.
- GET  /api/folders/:id/contents - List subfolders and documents inside a folder; use `root` for the workspace root.
- DELETE /api/folders/:id - Soft-delete a folder.
- PATCH /api/folders/:id - Update a folder's parent (`parent_id`) and/or rename it (`name`).
- GET  /api/docs/openapi.json - Generated OpenAPI specification (JSON).

Tags
----
- GET  /api/tags - List all tags with usage counts.
- POST /api/tags - Create a new tag.
- PATCH /api/tags/:id - Update a tag's label or color.
- DELETE /api/tags/:id - Remove a tag; fails with 400 if still assigned to any document.

Correspondents
--------------
- GET  /api/correspondents - List correspondents with usage totals and per-role counts (roles: `sender`, `receiver`, `other`).
- POST /api/correspondents - Create a correspondent (name + optional metadata JSON).
- PATCH /api/correspondents/:id - Update name and/or metadata.
- DELETE /api/correspondents/:id - Remove a correspondent; fails with 400 if referenced by any document.