Tool federation
Tool federation lets one participant publish a tool as a capability and lets applications on other machines discover and invoke it at runtime. The provider keeps its credentials and executes the operation locally.
provider announces a typed tool
→ caller discovers it by capability
→ authority is evaluated
→ provider executes locally
→ caller receives the permitted resultWhat federation adds
Live discovery. Providers announce tools through the capability fold. A watch reports when tools appear, change, or disappear, so callers do not maintain a static server list.
Provider-local authority. The provider decides who may invoke the tool and keeps any API keys or device credentials required to execute it.
Scoped visibility. A tool may be public, visible only to its owner organization, or encrypted for organizations holding a discovery grant. Callers outside the audience do not receive the descriptor.
Portable schemas. Tool descriptors carry input and output schemas. A caller can inspect or generate bindings for a tool it discovered at runtime.
The pieces
| Piece | Role | Documentation |
|---|---|---|
| Capability announcements | publish what a provider offers | Capabilities |
serve_tool, call_tool, list_tools, watch_tools | serve, discover, and invoke tools | Discover and invoke |
| nRPC | typed request/response and streaming transport | nRPC |
| Organization authority | control discovery and invocation | Private capabilities |
| MCP bridge | publish MCP tools on Net or expose Net to an MCP host | Net and MCP |
| A2A | delegate a longer job to another agent | Agent-to-agent |
| Agent identity | identify the principal an agent represents | Agent identity |
MCP tools and native capabilities
net-mesh wrap publishes tools from an existing stdio MCP server. net-mesh mcp serve exposes mesh capabilities to a local MCP host.
Bridged tools retain request/response semantics and carry
compat_tier: "mcp_bridge". Native Net capabilities can additionally define
streams, artifact movement, migration, and Net task state. Choose native semantics
when the operation needs them; the bridge is sufficient for ordinary MCP calls.
When federation is unnecessary
Use MCP directly when tools are fixed, local, and known to one host. Federation is useful when providers change at runtime, capabilities span machines or organizations, or credentials must remain on the provider.
See also: