Content
# Agent Relay
[](https://github.com/mmmikael/arelay/actions/workflows/ci.yml)
[](https://github.com/mmmikael/arelay/actions/workflows/github-code-scanning/codeql)
[](LICENSE)
[](https://nodejs.org/)
[](https://www.typescriptlang.org/)
[](https://svelte.dev/)
[](https://arelay.app)
Agent Relay is where your AI agents ask permission. Agents draft emails, request spend, and
deliver finished work into a private, end-to-end encrypted inbox; nothing leaves, sends, or
charges until you approve it. Anything that can make HTTP requests can use it — Cursor,
Codex, Claude Code, cron jobs, webhooks, or your own backend — and it is open source under
MIT, so you can run it yourself.
An optional **Email Review Relay** plugin adds a human-in-the-loop outbound email path: agents submit
encrypted drafts, you preview them in the same inbox, then approve or reject before anything
is sent. It is enabled on [arelay.app](https://arelay.app); self-hosters can turn it on with
`EMAIL_REVIEW_RELAY_ENABLED=true` ([setup](#email-review-relay)).
**Two ways to use it:**
- **[arelay.app](https://arelay.app)** — hosted service; sign up and connect your agents
(no deployment).
- **Self-host** — run this repo on your own infrastructure under the MIT license.
## Contents
### Using [arelay.app](https://arelay.app)
- [Get started](#get-started)
- [Connect your AI agent](#connect-your-ai-agent)
- [Encryption (required)](#encryption-required)
- [Email Review Relay](#email-review-relay)
- [Features](#features)
### Self-hosting
- [Development setup](#development-setup)
- [Environment variables](#environment-variables)
- [Deploy to production](#deploy-to-production)
- [Plugins](#plugins)
- [Tech stack](#tech-stack)
### Reference
- [Contributing & help wanted](#contributing--help-wanted)
- [Security model](#security-model)
- [Terms of Service](https://arelay.app/terms) · [Privacy Policy](https://arelay.app/privacy)
- [Contributing](./CONTRIBUTING.md)
- [License](#license)
---
## Using [arelay.app](https://arelay.app)
The hosted service at [arelay.app](https://arelay.app) handles deployment, database,
storage, backups, TLS, and updates. The security model is the same as self-hosting:
encrypted deliveries are decrypted in your browser, not on the server. The one exception is
approving an email draft: the decrypted email is sent to the server in that request so it can
be delivered, and is never stored as plaintext. Email itself is not end-to-end encrypted, so
the recipient's mail provider sees the same content permanently.
### Get started
1. Open **[arelay.app](https://arelay.app)** and create an account with a passkey.
2. Accept the [Terms of Service](https://arelay.app/terms) and
[Privacy Policy](https://arelay.app/privacy) during signup (required on the hosted
service).
3. Complete **Set up encryption** on first portal visit (passkey + recovery key).
4. In the portal, open **Account → Agent tokens** and create a named token for each agent
or integration.
5. Copy the token once — it is shown only at creation time.
6. Your inbox updates automatically when agents send deliveries (refresh every few seconds).
Sign-in uses passkeys (WebAuthn), not passwords or social login. No Google, Apple, or
Microsoft account is required. If terms or privacy are updated later, existing accounts are
prompted to accept the new versions before continuing.
### Connect your AI agent
Agent Relay is agent-agnostic: any client that speaks HTTP and follows the
[E2EE envelope format](#encryption-required) can deliver. Pick the path that fits your setup:
| Integration path | Best for |
| ------------------------------------- | -------------------------------------------------------------------------------------------------------------- |
| [CLI & MCP server](#cli--mcp-server) | Fastest start: one command from any shell, or native MCP tools in Claude Code, Cursor, and Claude Desktop |
| [Agent skill](#agent-skill) | Cursor, Codex, Claude Code, Hermes Agent, and other [Agent Skills](https://agentskills.io/specification) hosts |
| [Direct HTTP API](#direct-http-api) | Custom scripts, backends, webhooks, scheduled jobs |
| [Platform plugins](#platform-plugins) | Platform-specific hooks, e.g. Hermes cron delivery |
Whichever path you choose, set these where your agent runs — **never commit tokens**:
| Variable | Value for [arelay.app](https://arelay.app) |
| -------------- | ------------------------------------------ |
| `ARELAY_URL` | `https://arelay.app` |
| `ARELAY_TOKEN` | Token from Account → Agent tokens |
Every request uses `Authorization: Bearer <ARELAY_TOKEN>`.
#### CLI & MCP server
The [`@arelay/cli`](./packages/arelay) npm package wraps the API and all envelope encryption.
Deliver from any shell:
```bash
export ARELAY_TOKEN=ar_... # from Account → Agent tokens
npx -y @arelay/cli send report.md --title "Q2 revenue report"
```
Or register it as an MCP server so agents can deliver work natively
(`deliver_to_inbox`, `list_inbox_sessions`, `submit_email_draft` tools):
```bash
# Claude Code
claude mcp add arelay --env ARELAY_TOKEN=ar_... -- npx -y @arelay/cli mcp
```
`npx -y @arelay/cli check` verifies the token and encryption setup. The package also exports a
typed SDK (`import { ArelayClient } from '@arelay/cli'`) — see its
[README](./packages/arelay/README.md). Self-hosters point it at their deployment with
`ARELAY_URL`.
#### Agent skill
Install the [`agent-relay`](https://github.com/mmmikael/arelay-skills/tree/main/skills/agent-relay) skill (requires
[portal E2EE setup](#encryption-required)):
```bash
npx skills add mmmikael/arelay-skills --skill agent-relay -g -y
```
Hermes Agent:
```bash
hermes skills tap add mmmikael/arelay-skills
hermes skills install mmmikael/arelay-skills/agent-relay
```
#### Direct HTTP API
Anything that can POST JSON can deliver: fetch the public key from
`GET /api/agent/e2ee/config`, encrypt locally, create a session, and upload artifacts. See
the [API reference](https://github.com/mmmikael/arelay-skills/blob/main/skills/agent-relay/references/api-reference.md)
and the bundled Node reference scripts in the skill for working encryption code.
#### Platform plugins
**Hermes cron** (`--deliver arelay`) needs [arelay-hermes-plugin](https://github.com/mmmikael/arelay-hermes-plugin).
Cron runs in the **gateway**, not the interactive CLI — put credentials in
`~/.hermes/.env` (including `AGENT_RELAY_HOME_CHANNEL=https://arelay.app`), install the
plugin, then restart the gateway:
```bash
hermes plugins install mmmikael/arelay-hermes-plugin --enable
# ~/.hermes/.env: AGENT_API_TOKEN, AGENT_RELAY_URL, AGENT_RELAY_HOME_CHANNEL
# (the Hermes plugin reads its own variables, not the CLI's ARELAY_* ones)
hermes gateway start
/cron add "0 9 * * *" "Your prompt. Never use [SILENT]." --deliver arelay
```
### Encryption (required)
All agent deliveries must be end-to-end encrypted. Complete **Set up encryption** during
[Get started](#get-started); unlock in the browser when viewing the inbox. Agents fetch your
public key from `GET /api/agent/e2ee/config` and upload encrypted sessions and artifacts.
Plaintext agent payloads return `400` (`plaintext_not_allowed`); unconfigured accounts get
`428` (`e2ee_required`).
### Email Review Relay
On [arelay.app](https://arelay.app), agents POST encrypted email drafts; each appears as an
inbox session you **Approve** (send via your Cloudflare credentials) or **Reject**.
1. **Account → Email sending (Cloudflare API)** — save your Cloudflare Account ID and API
token (encrypted server-side; used only when you approve).
2. Use the **agent-relay** skill — drafts use the same E2EE envelopes as file deliveries.
API details and self-host setup: [Plugins](#plugins).
### Features
- Mobile-friendly email-style inbox
- Email Review Relay: agents draft outbound mail; you approve before send
- Artifact preview and download (text, Markdown, HTML, PDF, images)
- Sandboxed HTML/Markdown preview (external links and media stripped)
- End-to-end encrypted deliveries only
- Passkey sign-in (one passkey per account)
- Named agent API tokens with per-token revoke
- Storage limits: 25 MB per artifact, 500 MB per account
---
## Self-hosting
Run Agent Relay on your own PostgreSQL and S3-compatible storage. Useful when you need full
data residency control or a private deployment.
### Development setup
```bash
npm install
cp .env.example .env
npm run db:migrate:local
npm run dev
```
Open [http://127.0.0.1:5173](http://127.0.0.1:5173) and create an account with a passkey.
Without Cloudflare or SMTP configured, verification codes are printed to the server
console.
Database schema changes are managed with Drizzle migrations. Edit the Drizzle schema,
generate a migration with `npm run db:generate`, review the generated SQL, then apply it
with `npm run db:migrate:local`.
Run unit tests:
```bash
npm test
```
To test migrations against a disposable empty database, set `TEST_DATABASE_URL` and run:
```bash
npm run db:smoke
```
### Environment variables
| Variable | Description |
| ---------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `SESSION_SECRET` | Secret for signing human session cookies. Generate with `openssl rand -hex 32`. |
| `SESSION_VERSION` | Bump this to invalidate existing human sessions. |
| `ORIGIN` | Public site URL for CSRF checks and absolute links. In production, set to your canonical URL, for example `https://arelay.app`. |
| `WEBAUTHN_RP_NAME` | Passkey relying party display name. Defaults to `Agent Relay`. |
| `WEBAUTHN_RP_ID` | Passkey relying party ID. For production on arelay.app, use `arelay.app`. |
| `WEBAUTHN_ORIGIN` | Expected passkey origin, for example `https://arelay.app`. |
| `DATABASE_URL` | PostgreSQL connection string. |
| `CLOUDFLARE_ACCOUNT_ID` | Cloudflare account ID for [Email Sending](https://developers.cloudflare.com/email-service/). Use when your sending domain is on Cloudflare DNS. |
| `CLOUDFLARE_API_TOKEN` | Cloudflare API token with Email Sending permission. |
| `EMAIL_FROM` | Required when Cloudflare or SMTP is configured. Sender address for verification emails, for example `Agent Relay <no-reply@yourdomain.com>`. |
| `SMTP_HOST` | SMTP host for account email verification. Used when Cloudflare Email Sending is not configured. |
| `SMTP_PORT` | SMTP port. Defaults to `587`, or `465` when `SMTP_SECURE=true`. |
| `SMTP_SECURE` | Set to `true` for implicit TLS SMTP. |
| `SMTP_USER` | SMTP username, if your provider requires authentication. |
| `SMTP_PASSWORD` | SMTP password, if your provider requires authentication. |
| `S3_ENDPOINT` | S3-compatible endpoint URL. |
| `S3_BUCKET` | S3 bucket name. |
| `S3_PREFIX` | Object key prefix. Defaults to `agent-relay`. |
| `S3_ACCESS_KEY` | S3 access key. |
| `S3_SECRET_KEY` | S3 secret key. |
| `S3_REGION` | S3 region. Defaults to `us-east-1`. |
| `PORT` | HTTP port for `npm start`. Defaults to `3000`. Railway sets this automatically. |
| `BODY_SIZE_LIMIT` | Max HTTP request body size for adapter-node. Required for encrypted artifact uploads (a 25 MB file needs ~37 MB of JSON; the Pro plan's 100 MB needs ~140 MB). Defaults to `140M` when using `npm start`. |
| `NODE_ENV` | Set to `production` in production so session and WebAuthn cookies use `Secure`. |
| `EMAIL_REVIEW_RELAY_ENABLED` | Optional plugin. Set to `true` to enable Email Review Relay (off by default). |
When both Cloudflare Email Sending and SMTP are configured, Cloudflare is used.
### Deploy to production
**Requirements:**
- PostgreSQL
- S3-compatible object storage (see `scripts/iam-agent-relay-s3-policy.json` for a minimal
AWS IAM policy scoped to the `agent-relay/` prefix)
- Email delivery for account verification ([Cloudflare Email Sending](https://developers.cloudflare.com/email-service/) or SMTP)
- A stable HTTPS origin with correct WebAuthn RP settings
**Build and run:**
```bash
npm run db:migrate:local
npm run build
npm start
```
For a fresh production database, run migrations before starting the app. If you are moving
early account/auth records from an old database, copy only `users`, `webauthn_credentials`,
`e2ee_config`, and `agent_api_tokens`; leave inbox/content/plugin tables empty.
**Railway:**
1. Create a new service from [github.com/mmmikael/arelay](https://github.com/mmmikael/arelay).
2. Add PostgreSQL and link `DATABASE_URL`.
3. Add S3-compatible storage credentials.
4. Set `SESSION_SECRET`.
5. Set `WEBAUTHN_RP_ID` and `WEBAUTHN_ORIGIN` for your domain.
6. Configure email delivery: Cloudflare Email Sending (`CLOUDFLARE_ACCOUNT_ID`, `CLOUDFLARE_API_TOKEN`, `EMAIL_FROM`) or SMTP.
7. Set `NODE_ENV=production`.
8. Set `BODY_SIZE_LIMIT=140M` (or rely on `npm start`, which defaults to `140M` when unset). A value pinned to the old `40M` rejects the 100 MB artifacts the Pro plan allows.
9. Migrations run automatically on each deploy via `railway.toml` (`preDeployCommand: npm run db:migrate`).
10. Use `npm run build` as the build command and `npm start` as the start command.
**Existing production database (legacy `ensureSchema` → Drizzle):** on the first Drizzle deploy,
`npm run db:migrate` detects an existing `users` table, records the baseline migration in
`drizzle.__drizzle_migrations` without re-running `CREATE TABLE`, then applies any newer
migrations. No manual cutover is required for arelay.app-style databases that already match
the current schema. For a truly fresh host, run migrations on an empty database instead; if
you are rebuilding from scratch, copy only `users`, `webauthn_credentials`, `e2ee_config`, and
`agent_api_tokens` from the old database.
Point agents at your deployment URL: `ARELAY_URL=https://your-domain.example`.
### Backup and restore (self-hosting)
Agent Relay is not a backup or archival service — keep independent copies of important
content. Self-hosted operators are responsible for backups (see [SECURITY.md](SECURITY.md)).
Back up **both** stores; restoring only one leaves the deployment broken:
| Store | Contents |
| ------------------------------ | --------------------------------------------------------------------------------- |
| PostgreSQL | Accounts, passkeys, E2EE config, API tokens, inbox session metadata, email drafts |
| S3 (`S3_BUCKET` / `S3_PREFIX`) | Encrypted artifact blobs referenced by `inbox_artifacts.storage_key` |
**Backup**
```bash
# PostgreSQL (custom format; adjust connection string)
pg_dump "$DATABASE_URL" -Fc -f agent-relay-$(date +%Y%m%d).dump
# S3 prefix (AWS CLI example; use your provider's equivalent)
aws s3 sync "s3://${S3_BUCKET}/${S3_PREFIX}/" "./agent-relay-s3-$(date +%Y%m%d)/"
```
Use your host's managed snapshots (Railway Postgres, S3 versioning, etc.) when available.
**Restore**
1. Restore PostgreSQL, then object storage under the same `S3_BUCKET` and `S3_PREFIX`.
2. Keep the same `SESSION_SECRET` — encrypted Cloudflare credentials in the database cannot
be decrypted after restore if this value changes.
3. Run `npm run db:migrate` before starting the app (applies any migrations newer than the dump).
4. Spot-check: sign in with a passkey, open a session, download an artifact.
Delivered content stays E2EE-encrypted in backups. Recovery still requires the account
passkey and portal unlock; backups do not grant server-side plaintext access.
### Plugins
Optional features ship as plugins so minimal self-hosts stay lean. Plugin tables are
included in the Drizzle migrations; enable each plugin with an environment variable to
turn on its APIs and UI.
#### Email Review Relay
Agents submit outbound email drafts for human review before send. On [arelay.app](https://arelay.app)
the plugin is enabled by default; self-hosters set `EMAIL_REVIEW_RELAY_ENABLED=true`. When
disabled, plugin APIs return `404` and the portal UI is hidden.
**Account setup (portal):** open **Account** (`/portal/account`) → **Email sending (Cloudflare API)**
and paste your Cloudflare Account ID and API token.
These per-user credentials are encrypted server-side and used only when you approve a draft.
System `CLOUDFLARE_*` env vars remain for signup verification only.
**Agent API:** authenticated agents POST encrypted drafts to `/api/agent/email-drafts`
(`encrypted: true` with envelope fields). Plaintext drafts are rejected.
```json
{
"encrypted": true,
"encrypted_to": { "v": 1, "alg": "P-256-ECDH-A256GCM", "...": "..." },
"encrypted_from_email": { "...": "..." },
"encrypted_subject": { "...": "..." },
"encrypted_html": { "...": "..." },
"idempotency_key": "optional-stable-key"
}
```
The response includes the inbox session and draft (`status: pending`). Poll draft status
with `GET /api/agent/email-drafts/{id}` or `GET /api/agent/sessions/{id}` (includes
`email_draft` when applicable).
**Human review (portal):** open the session, decrypt and preview the HTML, then **Approve**
(sends via your Cloudflare credentials) or **Reject** (no send). Approve sends decrypted
fields in the request body so mail can be sent without storing plaintext server-side.
Approve requires Cloudflare Email Sending to be configured on the account.
Base64 `data:image/...` sources in approved HTML are converted in the browser to CID inline
attachments before sanitization and send. This keeps the encrypted portal preview
self-contained while making embedded images compatible with Gmail and other email clients.
### Tech stack
- SvelteKit 2, Svelte 5, TypeScript, Tailwind CSS
- PostgreSQL, S3-compatible object storage
- WebAuthn/passkeys
---
## Contributing & help wanted
Agent Relay is open source (MIT) and built in the open — contributions of all sizes are
welcome, and there's real room to have an impact while the project is young.
The fastest way in is to **build an integration**. Most integrations talk to the HTTP API
through the [`@arelay/cli`](./packages/arelay) SDK and never touch the core app, so you can
ship something useful without learning the whole codebase or the encryption internals. The
[**Building integrations guide**](./docs/building-integrations.md) walks through four levels
— from a dozen-line delivery script to a full server-side feature plugin — with working
examples.
A few things that would genuinely help:
- Delivery bridges and notifiers (Slack, Discord, Telegram)
- A GitHub Action for delivering CI artifacts
- Platform plugins for more agent runners
- An additional email backend (e.g. SMTP) for Email Review Relay
See [CONTRIBUTING.md](./CONTRIBUTING.md) for dev setup and conventions. Rough ideas are
welcome — open an issue to start a conversation.
---
## Security model
The hosted service publishes a plain-language [security page](https://arelay.app/security):
what is encrypted, what the server can see, the one exception at approval time, the
credentials it holds, subprocessors, and known limits. In brief:
- Human login uses passkeys and signed session cookies.
- Agent access uses named bearer tokens; only hashes are stored server-side.
- Agent tokens require E2EE setup; an encrypted copy of each token is stored for reveal in the browser.
- All agent content uses P-256 ECDH and AES-256-GCM envelopes; decryption happens client-side.
- Server preview/download/archive APIs return `e2ee_only`; the portal decrypts via ciphertext endpoints.
- HTML and Markdown previews render in sandboxed iframes; external URLs are stripped. Users can optionally open HTML artifacts or email drafts in a new browser tab to view unsanitized content they trust.
- Artifact uploads are capped at 25 MB per file and 500 MB per account.
- Download and preview URLs are short-lived.
Report security issues privately as described in [SECURITY.md](./SECURITY.md).
## License
Agent Relay is released under the [MIT License](./LICENSE).
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