mcp-zmq
Click on "Install Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type
@followed by the MCP server name and your instructions, e.g., "@mcp-zmqPublish 'hello' to topic 'test' on tcp://localhost:5555"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
mcp-zmq — MCP server for ZMQ messaging
mcp-name: io.github.daedalus/mcp-zmq
Install
pip install mcp-zmqRelated MCP server: Sentinel-MCP
Usage
MCP Server
mcp-zmqPython API
from mcp_zmq import zmq_publish, zmq_subscribe, zmq_send_request, zmq_listen_replyAvailable Tools
zmq_publish: Publish a message to a ZMQ PUB socketzmq_subscribe: Subscribe to messages from a ZMQ SUB socketzmq_send_request: Send a request via ZMQ REQ socketzmq_listen_reply: Listen for requests and reply via ZMQ REP socketzmq_pair_connect: Connect to a ZMQ PAIR socketzmq_pair_bind: Bind a ZMQ PAIR socketzmq_status: Get ZMQ server status
Development
git clone https://github.com/daedalus/mcp-zmq.git
cd mcp-zmq
pip install -e ".[test]"
# run tests
pytest
# format
ruff format src/ tests/
# lint
ruff check src/ tests/
# type check
mypy src/Available Tools
6 toolszmq_listen_replyA
Listen for requests and reply via ZMQ REP socket.
| Name | Required | Description | Default |
|---|---|---|---|
| bind_address | No | Address to bind REP socket. Defaults to "tcp://127.0.0.1:5556". | tcp://127.0.0.1:5556 |
| reply_message | No | Message to send in response to requests. Defaults to "OK". | OK |
| timeout_ms | No | Listen timeout in milliseconds. Defaults to 5000. |
Output Schema
| Name | Required | Description |
|---|---|---|
No output parameters | ||
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must disclose behavioral traits. It does not mention that this tool blocks until a request is received, how timeout affects the behavior (e.g., returns null or throws), or whether concurrent requests are handled. This leaves critical execution semantics undocumented.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single sentence that front-loads the core action ('Listen for requests and reply') and specifies the underlying protocol ('via ZMQ REP socket'). No unnecessary words; it is appropriately concise.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Although the input schema is fully covered and an output schema exists, the description omits important behavioral context such as the blocking nature of listening, timeout behavior, and error conditions. For a tool that modifies state (listens/replies), these gaps reduce completeness.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so the input schema already documents all three parameters (bind_address, reply_message, timeout_ms) with defaults and descriptions. The description adds no additional semantic meaning beyond the schema, meeting the baseline expectation.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states that the tool listens for requests and replies using a ZMQ REP socket, which is a specific verb+resource pattern. It distinguishes from sibling tools like zmq_publish (PUB), zmq_subscribe (SUB), zmq_send_request (REQ), and zmq_pair (PAIR) by focusing on the REP/REQ pattern.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description implies this tool is for request-reply server-side usage but does not explicitly state when to avoid it (e.g., for one-way messaging) or mention prerequisites like ZMQ context initialization. However, the context is clear given the naming and sibling tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
zmq_pair_bindB
Bind a ZMQ PAIR socket for bi-directional communication.
| Name | Required | Description | Default |
|---|---|---|---|
| bind_address | No | Address to bind PAIR socket. Defaults to "tcp://127.0.0.1:5557". | tcp://127.0.0.1:5557 |
| message | No | Optional message to send after binding. | |
| timeout_ms | No | Timeout in milliseconds. Defaults to 5000. |
Output Schema
| Name | Required | Description |
|---|---|---|
No output parameters | ||
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries full burden but only adds 'bi-directional communication' beyond the name. It does not disclose behaviors like blocking, error handling, or that binding creates a listening socket.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, concise sentence with no unnecessary words. It efficiently conveys the core action and purpose.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool has an output schema (so return values need not be detailed) and 3 optional parameters, the description is minimalist. It lacks context about typical usage (e.g., binding as server-side) or interaction with siblings like zmq_pair_connect.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% with clear descriptions and defaults for all 3 parameters. The tool description adds no additional parameter meaning, but the schema already suffices, so baseline 3 is appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the action ('Bind') and the resource ('ZMQ PAIR socket'), with the purpose ('for bi-directional communication'). It distinguishes from sibling tools like zmq_pair_connect, which connects instead of binds.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided on when to use this tool versus alternatives like zmq_pair_connect, zmq_publish, etc. There is no mention of prerequisites, typical workflow, or scenarios where binding is appropriate.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
zmq_pair_connectB
Connect to a ZMQ PAIR socket for bi-directional communication.
| Name | Required | Description | Default |
|---|---|---|---|
| connect_address | No | Address to connect PAIR socket. Defaults to "tcp://127.0.0.1:5557". | tcp://127.0.0.1:5557 |
| message | No | Optional message to send after connecting. | |
| timeout_ms | No | Timeout in milliseconds. Defaults to 5000. |
Output Schema
| Name | Required | Description |
|---|---|---|
No output parameters | ||
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries full burden but only states 'Connect' and 'bi-directional communication'. It fails to disclose blocking behavior, connection failure handling, state management, or disconnection procedures, leaving critical behavioral traits undocumented.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, concise sentence that is front-loaded. It is not verbose, but could potentially include more information without sacrificing conciseness, earning a 4.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool has three parameters (all documented), an output schema, and no annotations, the description lacks context about when to use it, prerequisites (e.g., need a bind endpoint), and behavior details like timeout handling, making it incomplete for an AI agent.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so baseline is 3. The description does not add meaning beyond the schema's parameter descriptions, but it is acceptable as the schema already handles parameter semantics adequately.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the action ('Connect') and the resource ('ZMQ PAIR socket'), with the phrase 'bi-directional communication' distinguishing it from siblings like zmq_pair_bind (bind vs connect) and zmq_publish/zmq_subscribe (pub/sub pattern).
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description does not provide guidance on when to use this tool versus alternatives such as zmq_pair_bind, nor does it explain that connecting requires a corresponding bind or the implications of using a PAIR pattern over others.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
zmq_publishB
Publish a message to a ZMQ PUB socket.
| Name | Required | Description | Default |
|---|---|---|---|
| topic | Yes | Message topic/topic filter for subscribers. | |
| message | Yes | Message payload to publish. | |
| bind_address | No | Address to bind PUB socket. Defaults to "tcp://127.0.0.1:5555". | tcp://127.0.0.1:5555 |
Output Schema
| Name | Required | Description |
|---|---|---|
No output parameters | ||
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must disclose behavioral traits like blocking, socket state requirements, or failure modes. It only states 'Publish a message', omitting whether the send is fire-and-forget or what happens if no subscribers are connected.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single concise sentence that gets to the point. It could benefit from slightly more context, but it is well-structured and front-loaded.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Despite having an output schema and complete parameter coverage, the description leaves out important context such as whether the socket must already be bound or if the publish is synchronous. It is not sufficiently complete for an agent to confidently use the tool without additional knowledge.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, with each parameter already described (topic, message, bind_address with default). The description adds no additional meaning beyond the schema, so baseline 3 is appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the verb 'publish' and resource 'message to a ZMQ PUB socket', which conveys the core purpose. However, it does not explicitly differentiate from sibling tools like zmq_send_request or zmq_subscribe, though the socket type 'PUB' hints at publish-subscribe pattern.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
No explicit guidance on when to use this tool vs. alternatives such as zmq_subscribe or zmq_send_request. The socket type (PUB) implies a broadcast pattern, but the description does not articulate use cases or exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
zmq_send_requestC
Send a request via ZMQ REQ socket.
| Name | Required | Description | Default |
|---|---|---|---|
| message | Yes | Request payload to send. | |
| connect_address | No | Address to connect REQ socket. Defaults to "tcp://127.0.0.1:5556". | tcp://127.0.0.1:5556 |
| timeout_ms | No | Request timeout in milliseconds. Defaults to 5000. |
Output Schema
| Name | Required | Description |
|---|---|---|
No output parameters | ||
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description should fully disclose behavior. It only says 'send a request' but does not state that the REQ socket blocks until a reply is received, or that timeout_ms controls this wait. The existence of an output schema partially compensates for return value, but the blocking nature is critical and omitted.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single sentence, efficiently conveying the core action. It could include more detail without becoming verbose, so it is concise but not overly terse.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a messaging tool with 3 parameters and an output schema, the description is incomplete. It does not explain the request-reply pattern, the need for a listener, or the blocking behavior. The schema and output schema fill some gaps, but the high-level interaction model is missing.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so each parameter is documented. The tool description adds only the context of 'via ZMQ REQ socket', which is marginally useful but not essential. Baseline 3 is appropriate as the description adds little beyond the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the verb 'Send' and the resource 'a request via ZMQ REQ socket', which distinguishes it from siblings like zmq_listen_reply (listening) or zmq_publish (publish). However, it does not explicitly differentiate from other request-based tools or mention the one-shot nature.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance on when to use this tool vs. alternatives. It does not mention that it requires a corresponding reply listener (e.g., zmq_listen_reply) or that it is for request-reply pattern only.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
zmq_subscribeB
Subscribe to messages from a ZMQ SUB socket.
| Name | Required | Description | Default |
|---|---|---|---|
| topic_filter | No | Topic to subscribe to. Empty string subscribes to all topics. | |
| connect_address | No | Address to connect SUB socket. Defaults to "tcp://127.0.0.1:5555". | tcp://127.0.0.1:5555 |
| timeout_ms | No | Receive timeout in milliseconds. Defaults to 5000. |
Output Schema
| Name | Required | Description |
|---|---|---|
No output parameters | ||
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of disclosing behavioral traits. It fails to mention whether the call blocks, handles timeouts, or requires persistent connections, leaving critical runtime behavior unspecified.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, focused sentence that immediately conveys the purpose. There is no extraneous information, and every word contributes to understanding.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Despite the presence of an output schema, the description lacks context about invocation behavior (e.g., blocking vs. non-blocking, message retrieval pattern) and does not compensate for the absence of annotations, leaving the definition incomplete for reliable tool selection.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so the baseline is 3. The tool description adds no additional meaning beyond the schema's parameter descriptions, which are already informative.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the specific verb 'subscribe' and resource 'messages from a ZMQ SUB socket'. It effectively distinguishes this tool from its siblings (e.g., zmq_publish, zmq_send_request) by focusing on the subscription pattern.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided on when to use this tool over alternatives, nor are there any prerequisites or context for use. The description only states the basic action, leaving the agent unaware of appropriate scenarios.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
TDQS
Each tool targets a distinct ZMQ socket type or role (REP, PAIR bind/connect, PUB, REQ, SUB), with no overlap in purpose. Agents can clearly distinguish them.
All tools follow a consistent zmq_verb_noun pattern using snake_case, making the naming predictable and uniform across the set.
With 6 tools covering essential ZMQ socket types (REQ/REP, PUB/SUB, PAIR), the count is well-scoped and each tool serves a clear purpose.
The set covers fundamental ZMQ patterns but lacks support for PUSH/PULL, DEALER/ROUTER, and cleanup actions like disconnect. Minor gaps exist but core workflows are addressed.
Maintenance
Resources
Unclaimed servers have limited discoverability.
Looking for Admin?
If you are the server author, to access and configure the admin panel.
Related MCP Connectors
Broad, OAuth-protected provider and financial-domain API tools for research agents.
Anonymous public tools for ZacharyR0th. See the published agent boundary before use.
Publish, search, and promote time-sensitive news and messages through a public remote MCP server.
Agent communication platform for agent to agent messaging via MCP. Messages, channels, skills.
Related MCP Servers
- AlicenseNot gradedqualityFmaintenanceProvides utilities to help maintain MCP repositories, including testing tools, parameter type support, and multiple transports (STDIO, SSE, Streamable HTTP).169MIT
- AlicenseAqualityCmaintenanceExtensible trading-intelligence MCP server with diagnostic tools, structured logging, and tool registration; currently provides server info tool with plans for market data adapters.113Unlicense - libtelnet variant
- AlicenseNot gradedqualityAmaintenanceMinimal MCP server allowing Python functions to be served as MCP tools over stdio or HTTP, with a built-in client for connecting to MCP servers.2Apache 2.0
- AlicenseNot gradedqualityBmaintenanceA shared MCP hub that enables multiple coding-agent CLIs to register, discover, and communicate asynchronously via a standalone daemon. It provides MCP tools for agent registration, session management, non-blocking messaging, and cursor-based event reading.141MIT
Latest Blog Posts
- Who's Calling? MCP Hosts Are an Identity Blind Spot (And the Spec Knows It)By Om-Shree-0709 on .mcpAgent IdentityOAuth 2.1
- Your AI Chatbot Just Exposed Your CEO's Salary to an InternBy Om-Shree-0709 on .Agent IdentityMCP SecurityOAuth Delegation
- Why MCP Servers Need Execution Sandboxing (And Why Your Current Stack Isn't Enough)By Om-Shree-0709 on .Agentic AiPrompt InjectionWebAssembly
MCP directory API
We provide all the information about MCP servers via our MCP API.
curl -X GET 'https://glama.ai/api/mcp/v1/servers/daedalus/mcp-zmq'
If you have feedback or need assistance with the MCP directory API, please join our Discord server