notifyd

The notification service your agent can send through and run.
Email, SMS, WhatsApp, push, in-app inbox. One Rust binary. Postgres only. No dashboard: a digest endpoint and an MCP server instead.

Quick Start • Agent operations • API Reference • Architecture • Benchmarks • llms.txt • Contributing

What it is

Every product needs to send email, texts and in-app notifications. The usual options are a hosted SaaS billed per notification, or a self-hosted stack with MongoDB, Redis and four containers behind a React dashboard.

notifyd is the third option: a single 10 MB binary with PostgreSQL as its only dependency, that sends through the providers you already have (Resend, Cloudflare Email Service, any SMTP, AgentMail, Telnyx, Twilio, Web Push, FCM), with a real delivery engine (priorities, pacing, retries with Retry-After, provider failover, send windows, one-click unsubscribe) and no admin UI at all. Operating it is an API call or an MCP tool, so the person on call can be an AI agent.

your app / your agent ──POST /v1/send──▶ notifyd ──▶ email · sms · whatsapp · push · in-app (SSE)
your agent            ──POST /mcp─────▶ notifyd ──▶ digest · jobs · retries · suppressions · settings

Three instances run in production today, one per company, operated this way.

_{60 s explainer, invented data. MP4 · Remotion source}

Send in one call

curl -X POST https://notifyd.example.com/v1/send \
  -H "X-Api-Key: sk_myapp_xxx" \
  -H "Content-Type: application/json" \
  -d '{
    "channels": ["email", "in_app"],
    "subscriber_id": "user-1",
    "subject": "Your report is ready",
    "body": "Hey {{first_name}}, the analysis you requested is complete.",
    "vars": {"first_name": "Alice"},
    "priority": "normal",
    "idempotency_key": "report-42-ready"
  }'

Flat REST, curl is the SDK. Retries are safe (idempotency_key), scheduling is a field (scheduled_at), a marketing campaign is POST /v1/batch with thousands of subscribers per call and it lands in the bulk lane so it never delays a password reset. Follow any send with GET /v1/jobs/:id.

Let your agent run it

Most notification tools were designed for a human clicking through a dashboard. notifyd exposes the operator's job as tools, with the detail a human operator would need:

1. One call says what needs attention. GET /v1/admin/digest ranks findings and tells you the action for each one, in JSON or Markdown:

# notifyd digest — last 1d
Instance: commit e14e6f3, up 3d, email resend (+ smtp fallback), sms telnyx

## Findings
- **warning** — Primary email provider `resend` is resting for 47s after refusing messages; `smtp` is delivering.
  _Nothing lost. Check the primary provider's status page; if it repeats, lower EMAIL_RATE_PER_SEC or move the primary role to the other provider._
- **warning** — Bounce rate 5.3 % over the window (14 bounced / 263 delivered).
  _Above 5 % providers throttle or suspend the sender. Clean the recipient list; suppressions are applied automatically._
- **warning** — 3 job(s) failed in the last 1d (0.1 % of terminal jobs). Top cause: 422 unverified sender domain.
  _Inspect with list_jobs(status=failed); permanent errors need a fix on the caller side, then retry_job._

## Queue          pending 0, retry 2, processing 0
## Outcomes       email/resend 4 812 sent, 3 failed · in_app 1 203 sent
## Latency        email p50 0.6s, p95 2.1s (scheduled → accepted by provider)
## Deliverability delivered 4 790, bounced 14, complained 0, unsubscribed 9

2. The same operations as MCP tools. POST /mcp is a Streamable HTTP MCP server (current spec revision, legacy initialize kept). Add it to Claude Code, Claude Desktop, Cursor or your own agent:

{ "mcpServers": { "notifyd": {
  "type": "http", "url": "https://notifyd.example.com/mcp",
  "headers": { "Authorization": "Bearer ${NOTIFYD_ADMIN_API_KEY}" } } } }

Every tool carries readOnlyHint / destructiveHint annotations and an outputSchema. A read-only operator key (READONLY_API_KEY) exposes only the read tools, for an agent that reports but must not act. Every MCP call is audited.

3. Everything an agent needs to integrate is in the repo. docs/llms.txt is the whole API in plain text for a context window; three Agent Skills ship in skills/ (notifyd-operate, notifyd-integrate, notifyd-deploy):

npx skills add rmzlb/notifyd

Published on the official MCP registry as mcp-name: io.github.rmzlb/notifyd (server.json). Full operator guide: docs/AGENT.md.

Features

Channels

• Email — Resend, Cloudflare Email Service, AgentMail, any SMTP (lettre), attachments, per-project sender identity
• SMS — Telnyx or Twilio, swap with one variable
• WhatsApp — Telnyx
• Push — Web Push (VAPID) or FCM
• In-app inbox — REST + realtime SSE (EventSource), read / archive / star, unread badge, multi-replica through Postgres NOTIFY

Delivery engine

• Priorities — critical, normal, bulk lanes; /v1/batch and campaign tags land in bulk
• Pacing — token bucket per channel (EMAIL_RATE_PER_SEC); a provider 429 pauses that channel for Retry-After without consuming an attempt, other channels keep flowing, and when it resumes the claim order puts critical first
• Retries — 30 s → 2 m → 10 m → 30 m → 2 h with jitter, 4xx fail fast, rejected batches fall back item by item
• Failover — second email provider with a circuit breaker (EMAIL_FALLBACK_PROVIDER)
• Send windows — quiet hours per project, evaluated in each subscriber's timezone
• Scheduling, idempotency, stuck-job reaper, batch idempotency

Governance

• Unsubscribe — RFC 8058 List-Unsubscribe one-click on every marketing email, suppression scopes all / marketing
• Preferences — per-subscriber opt-in / opt-out
• Multi-project — one instance, many projects, isolated by API key, key rotation with a grace period
• PII masking in logs, audit log of every mutation, per-project rate limit

Operations

• Digest, MCP server, Agent Skills, llms.txt
• Metrics — /v1/metrics, /v1/metrics/prometheus, per-template metrics
• Webhooks — delivery events to your endpoints
• Workflows — event-triggered multi-step sequences, state in Postgres
• Templates — {{variable}} substitution, stored per project

Quick Start

Docker (recommended)

The image reads its configuration from environment variables; no config file to mount.

git clone https://github.com/rmzlb/notifyd.git && cd notifyd
cat > .env <<'EOF'
JWT_SECRET=change-me-32-random-chars-minimum
ADMIN_API_KEY=change-me-32-random-chars-minimum
RESEND_API_KEY=re_xxx
EMAIL_FROM=notifications@yourdomain.com
EOF
docker compose up -d          # notifyd + Postgres 16, http://localhost:3400

Create a project and get its API key: