stdio Transport

The stdio binding carries ANIP over JSON-RPC 2.0 on stdin/stdout. An agent launches the ANIP service as a subprocess and communicates without opening a network port.

When to use stdio

• Agent spawns a local service as a subprocess (like MCP's stdio transport)
• No network port is desirable (sandboxed environments, CLI tools)
• IDE integrations where the editor manages the process lifecycle

Wire format

Messages are JSON-RPC 2.0 objects, one per line, on stdin (client→server) and stdout (server→client):

{"jsonrpc": "2.0", "id": 1, "method": "anip.discovery", "params": {}}

{"jsonrpc": "2.0", "id": 1, "result": {"anip_discovery": {"version": "0.11.0", ...}}}

Method mapping

Each ANIP operation maps to a JSON-RPC method:

ANIP Operation	JSON-RPC Method
Discovery	anip.discovery
Manifest	anip.manifest
JWKS	anip.jwks
Issue token	anip.tokens
Permissions	anip.permissions
Invoke	anip.invoke
Audit	anip.audit
Checkpoints	anip.checkpoints

Authentication

Since there's no HTTP header in stdio, auth is passed in the request params:

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "anip.invoke",
  "params": {
    "capability": "search_flights",
    "parameters": {"origin": "SEA", "destination": "SFO"},
    "auth": {"bearer": "demo-key"}
  }
}

Runtime support

Available in all five runtimes: TypeScript (@anip/stdio), Python (anip-stdio), Java (anip-stdio), Go (stdioapi), C# (Anip.Stdio).