arelay

Agent Relay (arelay) is an open-source, MIT-licensed service that gives AI agents a private, end-to-end encrypted inbox for delivering artifacts to people. Agents can submit reports, files, requests, and outbound email drafts; humans review and approve in a browser before anything is sent, spent, or charged. The project is agent-agnostic: clients that make HTTP requests can use the API, and documentation lists CLI/MCP server, Agent Skills, direct HTTP API, and platform plugin paths. The @arelay/cli npm package provides send and check commands plus an MCP server exposing tools such as deliver_to_inbox, list_inbox_sessions, and submit_email_draft. A typed SDK is exported for integrations. The web application is built with SvelteKit 2, Svelte 5, TypeScript, and Tailwind CSS. Persistence uses PostgreSQL and S3-compatible object storage, and authentication uses WebAuthn passkeys. Account setup requires enabling encryption with a passkey and recovery key. All agent deliveries must be end-to-end encrypted; plaintext agent payloads are rejected. Inbox sessions support preview and download for text, Markdown, HTML, PDF, and images, with sandboxed HTML and Markdown preview that strips external links and media. Documented storage limits are 25 MB per artifact and 500 MB per account. Named agent API tokens can be created and revoked per token. Users can use the hosted arelay.app service or run the repository themselves. Self-hosting requires PostgreSQL, S3-compatible storage, an email path for account verification such as Cloudflare Email Sending or SMTP, and a stable HTTPS origin with WebAuthn settings. Environment variables cover sessions, database, WebAuthn, SMTP, S3, port, request body size, and optional plugins. Migrations use Drizzle. An optional Email Review Relay plugin lets agents submit encrypted email drafts, which a human approves before sending through per-user Cloudflare credentials; self-hosters enable it with EMAIL_REVIEW_RELAY_ENABLED=true. Backup guidance says to back up both PostgreSQL and the S3 bucket or prefix, keep SESSION_SECRET stable, and note that the service is not a backup or archival service. Deployment guidance includes a Railway workflow.