@a2a-compliance/schemas

Zod schemas for the A2A (Agent2Agent) protocol. Lets you parse and validate Agent Cards, JSON-RPC envelopes, Tasks, and Messages without depending on a full runtime.

npm i @a2a-compliance/schemas

What's in the box

Export	Description
`AgentCardSchema`	Zod schema for `/.well-known/agent-card.json`
`AgentCard`	TypeScript type inferred from the schema
`AGENT_CARD_WELL_KNOWN_PATH`	`'/.well-known/agent-card.json'`
`JsonRpcRequestSchema` / `JsonRpcResponseSchema`	JSON-RPC 2.0 envelopes
`JsonRpcErrorCode`, `A2AErrorCode`	Numeric constants for error taxonomy
`MessageSchema`, `PartSchema`	A2A Message + Part (text/file/data) union
`TaskSchema`, `TaskStateSchema`	A2A Task and its state enum
`makeProbeMessage(text)`	UUID-keyed valid Message for smoke testing
`isErrorResponse(r)`	Type guard — narrows a response to the error variant

Usage

import { AgentCardSchema } from '@a2a-compliance/schemas';

const res = await fetch('https://agent.example.com/.well-known/agent-card.json');
const parsed = AgentCardSchema.safeParse(await res.json());
if (!parsed.success) {
  console.error(parsed.error.issues);
  return;
}

console.log(parsed.data.name, '→', parsed.data.skills.length, 'skills');

Schemas are defined with Zod 4 and have zero runtime dependencies other than Zod. They run equally well in Node, Bun, Deno, the browser, and edge runtimes — no Node built-ins touched.

Spec version

Targets A2A protocol spec v0.3 and v1.0. Unknown fields are tolerated so cards from future minor versions still parse; missing required fields fail as expected.

@a2a-compliance/core — assertion engine that uses these schemas
@a2a-compliance/cli — command-line tool

License

MIT.