io.github.a4a-network/a4a-mcp
A4A (Agent-for-Agent Network)
Is the A4A (Agent-for-Agent Network) MCP server down? No. It answered initialize and tools/list in the probe of 2026-11-04.
Open E2EE messaging protocol and MCP server so AI agents of different people can talk directly.
alive probed 2026-11-14 · unchanged since 2026-11-04
- Run it
- uvx a4a-mcp@0.4.0.post1 (stdio, probed in a container with the network off)
- Host
- pypi.org
- Reports itself as
- a4a 0.4.0.post1
- Capabilities
- prompts, resources, tools
- Instructions
- 3 523 characters
- Of a 1M window
- 1.5 % of a 1M context window
- Count
- 15k tokens in Claude Opus 5.5, exact, measured 2026-11-04. With the Claude Code prefix mcp__…__ on each tool name: 16k. The o200k_base estimate is 9.1k. Counted again when the tool definitions change. Method.
- Repository
- https://github.com/a4a-network/a4a
- Website
- https://a4a.network
- Registry
- active, updated 2026-10-23 · registry entry
Most expensive tools
The Claude column scales the o200k estimate of each tool by this server's ratio of exact to estimate, 1.70×.
| Tool | ≈ Claude tokens | o200k estimate | Share of this server |
|---|---|---|---|
| a4a_publish_intent | 965 | 567 | 6 % |
| a4a_get_reputation | 691 | 406 | 4 % |
| a4a_make_agreement | 678 | 398 | 4 % |
| a4a_deliver | 644 | 378 | 4 % |
| a4a_open_file | 562 | 330 | 4 % |
Compare this server with others, or with the servers that share its tool set.
Same tool set as 1 other server
These registry entries have the same tool names and the same schema sizes.
- network.a4a/a4a-mcp pypi.org
More servers
Other registry entries on pypi.org, the ones next to this name; all of them.
- mcp-telegram-agent io.github.a19901201/mcp-telegram-agent · alive
- A2CR io.github.a2cr/a2cr-mcp · needs network
- Taiwan Patent MCP io.github.aa0101181514/tw-patent-mcp · alive
- UnrealMCP — AI Bridge for Unreal Engine 5 io.github.aadeshrao123/unreal-mcp · alive
- AkTools MCP Server io.github.aahl/mcp-aktools · alive
- Notify MCP Server io.github.aahl/mcp-notify · needs env
- STM32 GDB Debugger io.github.Zeraissh/stm32-gdb-mcp · alive
- Discrete Structures io.github.ZohaibCodez/discrete-structures · needs mcp<2
Servers that mention network.
- ac.snag/snag · needs auth
- UGC, the Human Ad Network africa.ugc/ugc · needs auth
- 69.ai ai.69ai/69ai · no DNS
- AgentMesh ai.agentmesh/mesh · needs auth
- Agentic Fabrication Network (AFN) ai.agenticfabricationnetwork/ufp · alive
- Affiliate Networks MCP ai.agenticaffiliate/affiliate-networks-mcp · needs auth
- Caulo ai.caulo/caulo · needs auth
- cnpj.ai ai.cnpj/mcp · needs auth
Badge for the README
The result of the latest probe, the tool count and the token cost. The feed has an entry for every probe that changed them.
A mail when this server changes
Stops answering, comes back, tool set or cost changes. One confirmation mail first, a stop link in every mail.
For the publisher
- The server answers initialize and tools/list. Nothing to fix.