Appwrite

Appwrite provides the full backend stack — auth, database, file storage, functions, and real-time — in a self-hostable Docker image, with Appwrite Cloud as the managed option. For agents: the server-side REST API enables user management, CRUD on database collections with role-based permissions, file uploads and retrieval, and invocation of serverless functions. Document-oriented collections with indexing. Storage with bucket-based file management. Strong Firebase/Supabase alternative for teams wanting self-hosted control. Confidence is docs-derived.

REST API at {hostname}/v1 (Cloud: cloud.appwrite.io/v1). Resources: account, users, databases, collections, documents, storage, functions, teams, messaging. GET /databases/{id}/collections/{id}/documents lists documents. POST /databases/{id}/collections/{id}/documents creates a document (documentId, data, permissions). GET /storage/buckets/{id}/files/{id}/download downloads file bytes. POST /functions/{id}/executions triggers a function. Collections support typed attributes with rich query operators: equal, notEqual, lessThan, greaterThan, contains, startsWith, orderAsc/Desc, limit, offset, cursor.

Two auth modes: (1) API Key (server-side): X-Appwrite-Key header with project API key, scope-based permissions (databases.read, documents.write, etc.). (2) JWT (client-side): user authenticates, receives JWT, passes in Authorization: Bearer header. HTTPS enforced. Projects isolated by project ID (X-Appwrite-Project header required). Granular document-level permissions via Appwrite permission system (role:all, user:${id}, team:${id}, etc.).

Standard HTTP status codes with JSON error objects ({message, code, type, version}). 401 for invalid API key, 400 for validation errors, 404 for missing document, 409 if documentId already exists. Rate limiting: Appwrite Cloud enforces per-project limits; self-hosted limits configurable. Function execution: sync returns output in response; async returns execution ID for polling. Appwrite Cloud uptime at status.appwrite.io. Self-hosted reliability is operator-managed.

appwrite.io/docs is comprehensive — REST API reference, platform SDKs for Web, Flutter, Android, iOS, Node.js, Python, PHP, Ruby, .NET, Dart, Kotlin, Swift, Deno. Getting started: Docker Compose one-liner for self-hosted, or Appwrite Cloud with free tier. Appwrite Console for visual collection/bucket/function management. Active community via Appwrite Discord (50k+ members) and GitHub. Open source (BSD 3-Clause).