Ntfy MCP Server

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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

Tool	Description
ntfy_publish_message	Send or update a push notification on an ntfy topic.
ntfy_manage_message	Clear or delete a previously-sent notification by sequence_id.
ntfy_fetch_messages	Poll cached messages from one or more topics with optional filters.
ntfy_search_emoji_tags	Look up ntfy emoji tag short codes for use in tags.

Resources

Resource	Description
ntfy://{topic}	Snapshot of a topic — latest 20 messages from the past hour, plus the topic's browser URL.

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

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
• 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

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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

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ntfy_fetch_messages _tool

• Returns a snapshot, not a live stream; accepts comma-separated topics (e.g. alerts,backups) and filters since (duration / timestamp / message ID / all / latest), priority, tags, id, title, message, scheduled-only
• 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
• Flags upstreamTruncated when ntfy capped the replay, and fails with upstream_malformed if the server doesn't return an ntfy message stream

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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

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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 (consent_declined, forbidden_topic, rate_limited, not_found, payload_too_large, and more) let callers branch on failure mode
• Fetch and emoji search report truncated, totalCount, and a notice naming the next step (pass nextCursor as cursor, advance offset)

Getting started

Add the following to your MCP client configuration file. Public ntfy.sh works out of the box without an account; for protected topics, generate an access token at https://ntfy.sh/account.

{
  "mcpServers": {
    "ntfy-mcp-server": {
      "type": "stdio",
      "command": "bunx",
      "args": ["ntfy-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info",
        "NTFY_DEFAULT_TOPIC": "your-topic-name"
      }
    }
  }
}

Or with npx (no Bun required):

{
  "mcpServers": {
    "ntfy-mcp-server": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "ntfy-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info",
        "NTFY_DEFAULT_TOPIC": "your-topic-name"
      }
    }
  }
}

Or with Docker:

{
  "mcpServers": {
    "ntfy-mcp-server": {
      "type": "stdio",
      "command": "docker",
      "args": [
        "run", "-i", "--rm",
        "-e", "MCP_TRANSPORT_TYPE=stdio",
        "-e", "NTFY_DEFAULT_TOPIC=your-topic-name",
        "ghcr.io/cyanheads/ntfy-mcp-server:latest"
      ]
    }
  }
}

For Streamable HTTP, set the transport and start the server:

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

Prerequisites

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

Installation

1. Clone the repository:

git clone https://github.com/cyanheads/ntfy-mcp-server.git

2. Navigate into the directory:

cd ntfy-mcp-server

3. Install dependencies:

bun install

4. Configure environment:

cp .env.example .env
# edit .env and set NTFY_DEFAULT_TOPIC (and auth, if needed)

Configuration

Variable	Description	Default
NTFY_SERVERS	JSON array of { baseUrl, authToken? | authUsername?+authPassword? } entries, one per ntfy server; the first is the default. Takes precedence over the single-server vars below.	—
NTFY_BASE_URL	Single-server shorthand — base URL of the ntfy server (no trailing slash). Used when NTFY_SERVERS is unset.	https://ntfy.sh
NTFY_DEFAULT_TOPIC	Topic used when a tool call omits topic.	—
NTFY_AUTH_TOKEN	Bearer access token (tk_…) for the single-server shorthand. Mutually exclusive with NTFY_AUTH_USERNAME / NTFY_AUTH_PASSWORD.	—
NTFY_AUTH_USERNAME	Basic-auth username for the single-server shorthand — required together with NTFY_AUTH_PASSWORD.	—
NTFY_AUTH_PASSWORD	Basic-auth password for the single-server shorthand — required together with NTFY_AUTH_USERNAME.	—
NTFY_REQUEST_TIMEOUT_MS	Per-attempt HTTP timeout in milliseconds. Each call is also capped at 50 s across all attempts.	15000
NTFY_MAX_RETRIES	Max retry attempts for transient upstream failures (5xx, network, 429).	3
NTFY_BLOCK_PRIVATE_HOSTS	When true, a per-call base_url override must resolve to a public address and redirects are not followed. Registered servers are exempt. Turn it on where callers you don't control can reach the server.	false
NTFY_ENABLE_EMOJI_TAGS	Set to false to disable ntfy_search_emoji_tags. An unrecognized value fails startup.	true
MCP_TRANSPORT_TYPE	Transport: stdio or http.	stdio
MCP_SESSION_MODE	HTTP session model: auto, stateful, or stateless. Over HTTP this server requires stateful (auto resolves to it); stateless is refused at start. Ignored on stdio.	stateful
MCP_HTTP_HOST	HTTP host.	127.0.0.1
MCP_HTTP_PORT	HTTP port.	3010
MCP_HTTP_ENDPOINT_PATH	HTTP endpoint path.	/mcp
MCP_AUTH_MODE	Auth mode: none, jwt, or oauth.	none
MCP_REQUEST_STATE_KEY	Recommended for HTTP. Key (≥ 32 bytes, e.g. openssl rand -base64 32, the same on every instance) that seals the consent requestState for 900 s; an invalid or expired state is rejected with -32602 invalid_request_state.	—
STORAGE_PROVIDER_TYPE	Where consent records live (600 s TTL). Multi-instance HTTP needs shared storage: filesystem (shared volume), supabase, or cloudflare-d1, not cloudflare-kv.	in-memory
MCP_LOG_LEVEL	Log level (RFC 5424).	info
LOGS_DIR	Directory for file-based logs (Node only; ignored on Workers).	./logs
LOG_TOOL_FAILURE_PAYLOADS	Log each failed tool call's arguments and result, redacted by key name and capped at LOG_TOOL_FAILURE_PAYLOAD_MAX_BYTES (default 16384). A secret inside a free-form value is not redacted.	false
OTEL_ENABLED	Enable OpenTelemetry instrumentation (spans, metrics, completion logs).	false

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

Running the server

Local development

• Build and run:

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

• 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 build -t ntfy-mcp-server .
docker run --rm -e NTFY_DEFAULT_TOPIC=your-topic -p 3010:3010 ntfy-mcp-server

The Dockerfile defaults to HTTP transport, stateful session mode, and logs to /var/log/ntfy-mcp-server. OpenTelemetry peer dependencies are installed by default — build with --build-arg OTEL_ENABLED=false to omit them.

Project structure

Directory	Purpose
src/index.ts	createApp() entry point — registers tools and resources, initializes services.
src/config	Server-specific environment variable parsing (NTFY_*) with Zod.
src/mcp-server/tools	Tool definitions (*.tool.ts).
src/mcp-server/resources	Resource definitions (*.resource.ts).
src/services/ntfy	ntfy HTTP client, types, and error classifier.
src/services/emoji-tags	Bundled emoji short-code reference and lookup service.
docs/ntfy	Mirrored upstream ntfy API docs (pinned commit in SOURCES.md).
tests/	Unit and integration tests mirroring src/.

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.