ntfy-mcp-server

Overview

Push notifications to your phone or desktop through ntfy. Publish, update, and manage notifications, poll a topic's recent history, and look up emoji short codes for tags.

Tools

Resources

ntfy_fetch_messages covers the same topic data with custom windows and filters when the resource's fixed defaults aren't enough.

Skills

Plugin, npm, Docker, and MCPB installs ship it from skills/; MCP clients that support the Skills extension read it as skill://ntfy-guide/SKILL.md.

Related MCP server: ntfy-me-mcp

Capability reference

ntfy_publish_message tool

• Topics are created on first publish — treat the topic name as a secret; anyone who knows it can publish or subscribe

• Takes title, priority (1–5), tags, click, attach, icon, filename, markdown, delay, email, call, cache, firebase, and up to three action buttons (view, broadcast, http, copy); body capped at 4096 bytes, empty body defaults to triggered; pass the original sequence_id to update a sent message

• Publishes with email, call, or a broadcast/http button ask the user to confirm the target before sending; declining fails with consent_declined

• A per-call base_url gets credentials only if it matches a registered server (NTFY_BASE_URL or an NTFY_SERVERS entry); otherwise the request is unauthenticated

• Failures carry typed reasons: payload_too_large (body, attachment, title, or combined tags over ntfy's limits), invalid_delay, invalid_attachment (malformed attach URL), and unverified_contact (email/call without a verified address or number, or without auth), alongside the shared reasons under Features

ntfy_manage_message tool

• operation: clear marks the notification read and dismisses it (subscribers see message_clear); delete removes it from the drawer (subscribers see message_delete)

• Every call asks the user to confirm the topic, sequence_id, and operation first; declining fails with consent_declined

• The original message stays in cache, and repeating an operation is safe; ntfy.sh accepts an unknown sequence_id, stricter deployments return not_found

ntfy_fetch_messages tool

• Returns a snapshot, not a live stream; accepts comma-separated topics (e.g. alerts,backups, each 1–64 characters) and filters since (duration / timestamp / message ID / all / latest), priority, tags, id, title, message, plus scheduled to include delayed messages

• Default window 10m, default limit 20, at most 100 per call; a larger window returns the newest limit messages with totalCount and a nextCursor to pass back as cursor. Bodies truncate at ~500 chars (messageTruncated gives the dropped count); refetch with id for the full text. upstreamTruncated flags a replay ntfy capped

• Failures carry typed reasons: invalid_since (malformed since value), cursor_not_found (the cursor's message expired, or came from a call with different topics, since, or filters), and upstream_malformed (the response wasn't an ntfy message stream), alongside the shared reasons under Features

ntfy_search_emoji_tags tool

• Case-insensitive substring match on tag names; omit query to list the reference in order

• limit default 25, at most 200 per call; page with offset using totalCount

• Returned tag strings go straight into ntfy_publish_message's tags

• On by default; set NTFY_ENABLE_EMOJI_TAGS=false to remove it from tools/list

ntfy://{topic} resource

• Fixed snapshot: latest 20 messages from the past hour plus the topic's browser URL, in the same shape as ntfy_fetch_messages (including upstreamTruncated)

• For custom windows or filters, use ntfy_fetch_messages

Features

Built on @cyanheads/mcp-ts-core: stdio and Streamable HTTP transports, pluggable auth (none / jwt / oauth), swappable storage (in-memory, filesystem, Supabase, Cloudflare KV/R2/D1), structured logging with optional OpenTelemetry tracing.

ntfy-specific:

• Retrying ntfy client with a per-attempt timeout, and each call capped at 50 s so it settles before an MCP client's 60 s default

• Per-server auth: credentials bind to each registered base URL (NTFY_BASE_URL or an NTFY_SERVERS entry), with bearer-token and basic-auth modes mutually exclusive

• User confirmation before a clear/delete, or a publish with email, call, or a broadcast/http button, on both stdio and Streamable HTTP

• Optional SSRF guard on base_url overrides (NTFY_BLOCK_PRIVATE_HOSTS); registered servers are exempt

• Bundled emoji-tag reference, regenerated from upstream docs/ntfy/emojis.md via scripts/build-emoji-tags.ts

Agent-friendly output:

• Publish and manage echo the resolved topic, ID, and timestamp; fetch also echoes the resolved since and applied filters

• Typed reason codes let callers branch on failure mode. Shared across the tools and the resource: forbidden_topic (ntfy refused the topic with 401/403: missing or insufficient credentials), rate_limited (429 after retries), upstream_unreachable (network failure, a 5xx that outlasted retries or whose Retry-After the call can't wait out, or no complete answer within the 50 s call deadline; carries retryAfter when ntfy sent one), upstream_malformed (a reply that isn't ntfy's message format or couldn't be read in full; publish and manage don't retry it, since the event may already be out). consent_declined, not_found, and the rest are listed per entry

• Fetch and emoji search report truncated, totalCount, and a notice naming the next step (pass nextCursor as cursor, advance offset)

Getting started

Add it to Claude Code:

claude mcp add ntfy-mcp-server -- npx -y ntfy-mcp-server

For other clients, add this to the MCP config file:

{
  "mcpServers": {
    "ntfy-mcp-server": {
      "command": "npx",
      "args": ["-y", "ntfy-mcp-server"]
    }
  }
}

Public ntfy.sh works without an account. Set NTFY_DEFAULT_TOPIC so calls can omit topic; for protected topics, add NTFY_AUTH_TOKEN (generate one at https://ntfy.sh/account). With claude mcp add, pass each as -e NAME=value after the server name; in JSON, put them under env. For Docker, a source build, or Streamable HTTP, see Running the server.

Configuration

See .env.example for the full list of optional overrides.

Running the server

Local development

Requires Bun v1.4.0 or higher (or Node.js v24+) and a topic on an ntfy server. Public ntfy.sh needs no account; self-hosted instances and protected topics may need a bearer token or basic-auth credentials.

• Clone and install:

  git clone https://github.com/cyanheads/ntfy-mcp-server.git
  cd ntfy-mcp-server && bun install
  cp .env.example .env   # set NTFY_DEFAULT_TOPIC (and auth, if needed)

• Build and run:

  # One-time build
  bun run rebuild
  
  # Run the built server
  bun run start:stdio
  # or
  bun run start:http

  For Streamable HTTP:

  MCP_TRANSPORT_TYPE=http MCP_HTTP_PORT=3010 NTFY_DEFAULT_TOPIC=your-topic bun run start:http
  # Server listens at http://127.0.0.1:3010/mcp

• Run checks and tests:

  bun run devcheck     # Lint, format, typecheck, security, changelog sync
  bun run test         # Vitest test suite
  bun run lint:mcp     # Validate MCP definitions against spec

Docker

docker run --rm -e NTFY_DEFAULT_TOPIC=your-topic -p 3010:3010 ghcr.io/cyanheads/ntfy-mcp-server:latest

The image defaults to HTTP transport, stateful session mode, and logs to /var/log/ntfy-mcp-server. To run it over stdio from an MCP client, use "command": "docker" with "args": ["run", "-i", "--rm", "-e", "MCP_TRANSPORT_TYPE=stdio", "-e", "NTFY_DEFAULT_TOPIC=your-topic", "ghcr.io/cyanheads/ntfy-mcp-server:latest"]. To build locally, docker build -t ntfy-mcp-server .. OpenTelemetry peer dependencies are installed by default — build with --build-arg OTEL_ENABLED=false to omit them.

Project structure

Development guide

See CLAUDE.md for development guidelines and architectural rules. The short version:

• Handlers throw, framework catches — no try/catch in tool logic

• Use ctx.log for request-scoped logging, ctx.state for tenant-scoped storage

• Wrap external API calls: validate raw → normalize to domain type → return output schema; never fabricate missing fields

• Per-tool errors[] contracts stay inline — repetition is intended for locality

Contributing

Issues are welcome. Run checks and tests before submitting:

bun run devcheck
bun run test

License

Apache-2.0 — see LICENSE for details.