feat(runtime): add Agent Document contracts

.changeset/agent-document-contracts.md

@@ -0,0 +1,7 @@
+---
+"@agent-bundle/runtime": minor
+---
+
+Add the versioned immutable Agent Document, bounded sequence-numbered render
+events, the protocol-oriented `Agent.*` vocabulary, and discriminated render
+invocation props while retaining the existing synchronous MCP and hook lowerers.

packages/rsc-runtime/README.md

@@ -24,11 +24,19 @@ const result = lowerMcpResult(
 );
 ```
 
-The package exports `Hook`, `Mcp`, `lowerHookResult`, `lowerMcpResult`,
-`createRscRequestContext`, `agent`, `runAgentRequest`, `available`,
-`unavailable`, and `AgentRequestError`. It does not own an
-RSC renderer, application state, transport, persistence, or host packaging.
-React 19 is a peer dependency and Node 22.19 or newer is required.
+The package also exports the protocol-oriented `Agent.*` vocabulary and the
+versioned `AgentDocument`/`AgentRenderEvent` contracts. `createAgentDocument`
+detaches and freezes a v1 document, enforcing finite depth, node-count, and
+byte limits. `createAgentRenderEventSequence` assigns monotonic sequence
+numbers to `shell | progress | replace | error | complete`, applies event
+bounds, and rejects post-completion writes with a typed `handoff-required`
+error. These contracts land beside the existing `Hook`/`Mcp` lowerers; those
+synchronous compatibility APIs remain operative.
+
+The package exports `Hook`, `Mcp`, `Agent`, both lowerers, the request-store
+APIs, and the Agent Document contracts. It does not yet own application state,
+transport, persistence, or host packaging. React 19 is a peer dependency and
+Node 22.19 or newer is required.
 
 Async server utilities and Server Components read the framework request store
 with `const context = await agent()`. The store is a versioned realm singleton

packages/rsc-runtime/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@agent-bundle/runtime",
   "version": "0.0.0",
-  "description": "React-element result primitives (an MCP result DSL) for Agent Bundle hook and MCP protocol results.",
+  "description": "Versioned Agent Document contracts and React protocol primitives for Agent Bundle runtimes.",
   "license": "MIT",
   "keywords": [
     "agent-bundle",