feat(runtime): complete ADR-002 bridge migration to BridgeProtocol

docs/adr/002-bridge-protocol.md

@@ -2,16 +2,16 @@
 
 ## Status
 
-**In Progress** (Core infrastructure complete, bridge migration pending)
+**Accepted** (Fully implemented)
 
 ### Implementation Progress
 
 - ✅ Phase 1: SafeCodec (TypeScript + Python)
 - ✅ Phase 2: Transport interface + ProcessIO, HttpIO, PyodideIO
-- ✅ Phase 3: WorkerPool
+- ✅ Phase 3: WorkerPool (PooledTransport)
 - ✅ BridgeProtocol base class
-- ⏳ Phase 4: Bridge migration (NodeBridge, HttpBridge, PyodideBridge)
-- ⏳ Phase 5: Cleanup and deprecations
+- ✅ Phase 4: Bridge migration (NodeBridge, HttpBridge, PyodideBridge)
+- ✅ Phase 5: Cleanup and documentation
 
 ## Context
 

examples/living-app/src/index.ts

@@ -124,14 +124,7 @@ async function main(): Promise<void> {
   setRuntimeBridge(bridge);
 
   if (codec === 'arrow') {
-    const info = await bridge.getBridgeInfo();
-    if (!info.arrowAvailable) {
-      // Why: fail fast with a clear message; otherwise the bridge will emit Arrow envelopes and the
-      // caller will see confusing decode errors.
-      throw new Error(
-        'Arrow mode requested but pyarrow is not installed in the Python environment. Install pyarrow or run with --json.'
-      );
-    }
+    // Enable Arrow decoder - will fail at decode time if pyarrow is not installed
     await enableArrowDecoder();
   }
 

src/index.ts

@@ -17,13 +17,15 @@ export { BridgeProtocol, type BridgeProtocolOptions } from './runtime/bridge-pro
 export { SafeCodec, type CodecOptions } from './runtime/safe-codec.js';
 // Transport - abstract I/O channel interface
 export type { Transport, TransportOptions, ProtocolMessage, ProtocolResponse } from './runtime/transport.js';
-export { isTransport, isProtocolMessage, isProtocolResponse } from './runtime/transport.js';
+export { PROTOCOL_ID, isTransport, isProtocolMessage, isProtocolResponse } from './runtime/transport.js';
 // Transport implementations
 export { ProcessIO, type ProcessIOOptions } from './runtime/process-io.js';
 export { HttpIO, type HttpIOOptions } from './runtime/http-io.js';
 export { PyodideIO, type PyodideIOOptions } from './runtime/pyodide-io.js';
 // WorkerPool - concurrent transport management
 export { WorkerPool, type WorkerPoolOptions, type PooledWorker } from './runtime/worker-pool.js';
+// PooledTransport - Transport adapter that wraps WorkerPool
+export { PooledTransport, type PooledTransportOptions } from './runtime/pooled-transport.js';
 export type { Disposable } from './runtime/disposable.js';
 export { isDisposable, safeDispose, disposeAll } from './runtime/disposable.js';
 export {
@@ -60,10 +62,10 @@ export {
 } from './runtime/errors.js';
 export { getRuntimeBridge, setRuntimeBridge, clearRuntimeBridge } from './runtime/index.js';
 
-// Runtime-specific exports
-export { NodeBridge } from './runtime/node.js';
-export { PyodideBridge } from './runtime/pyodide.js';
-export { HttpBridge } from './runtime/http.js';
+// Runtime-specific exports (Bridges using new BridgeProtocol architecture)
+export { NodeBridge, type NodeBridgeOptions } from './runtime/node.js';
+export { PyodideBridge, type PyodideBridgeOptions } from './runtime/pyodide.js';
+export { HttpBridge, type HttpBridgeOptions } from './runtime/http.js';
 
 // Core types
 export type {

src/runtime/bridge-protocol.ts

@@ -18,7 +18,7 @@
 
 import { BoundedContext, type ExecuteOptions } from './bounded-context.js';
 import { SafeCodec, type CodecOptions } from './safe-codec.js';
-import type { Transport, ProtocolMessage } from './transport.js';
+import { PROTOCOL_ID, type Transport, type ProtocolMessage } from './transport.js';
 
 // =============================================================================
 // TYPES
@@ -143,12 +143,13 @@ export class BridgeProtocol extends BoundedContext {
    * @throws BridgeTimeoutError if the operation times out
    */
   protected async sendMessage<T>(
-    message: Omit<ProtocolMessage, 'id'>,
+    message: Omit<ProtocolMessage, 'id' | 'protocol'>,
     options?: ExecuteOptions<T>
   ): Promise<T> {
     const fullMessage: ProtocolMessage = {
       ...message,
       id: this.generateId(),
+      protocol: PROTOCOL_ID,
     };
 
     return this.execute(async () => {
@@ -182,12 +183,13 @@ export class BridgeProtocol extends BoundedContext {
    * @throws BridgeTimeoutError if the operation times out
    */
   protected async sendMessageAsync<T>(
-    message: Omit<ProtocolMessage, 'id'>,
+    message: Omit<ProtocolMessage, 'id' | 'protocol'>,
     options?: ExecuteOptions<T>
   ): Promise<T> {
     const fullMessage: ProtocolMessage = {
       ...message,
       id: this.generateId(),
+      protocol: PROTOCOL_ID,
     };
 
     return this.execute(async () => {
@@ -209,12 +211,11 @@ export class BridgeProtocol extends BoundedContext {
   /**
    * Generate a unique request ID.
    *
-   * Format: req_{timestamp}_{counter}
-   * The combination of timestamp and monotonically increasing counter
-   * ensures uniqueness within a process lifetime.
+   * Returns a monotonically increasing integer that ensures uniqueness
+   * within a process lifetime.
    */
-  private generateId(): string {
-    return `req_${Date.now()}_${++this.requestId}`;
+  private generateId(): number {
+    return ++this.requestId;
   }
 
   // ===========================================================================
@@ -237,11 +238,13 @@ export class BridgeProtocol extends BoundedContext {
     kwargs?: Record<string, unknown>
   ): Promise<T> {
     return this.sendMessageAsync<T>({
-      type: 'call',
-      module,
-      functionName,
-      args,
-      kwargs,
+      method: 'call',
+      params: {
+        module,
+        functionName,
+        args,
+        kwargs,
+      },
     });
   }
 
@@ -261,11 +264,13 @@ export class BridgeProtocol extends BoundedContext {
     kwargs?: Record<string, unknown>
   ): Promise<T> {
     return this.sendMessageAsync<T>({
-      type: 'instantiate',
-      module,
-      className,
-      args,
-      kwargs,
+      method: 'instantiate',
+      params: {
+        module,
+        className,
+        args,
+        kwargs,
+      },
     });
   }
 
@@ -285,11 +290,13 @@ export class BridgeProtocol extends BoundedContext {
     kwargs?: Record<string, unknown>
   ): Promise<T> {
     return this.sendMessageAsync<T>({
-      type: 'call_method',
-      handle,
-      methodName,
-      args,
-      kwargs,
+      method: 'call_method',
+      params: {
+        handle,
+        methodName,
+        args,
+        kwargs,
+      },
     });
   }
 
@@ -303,9 +310,10 @@ export class BridgeProtocol extends BoundedContext {
    */
   async disposeInstance(handle: string): Promise<void> {
     await this.sendMessageAsync<void>({
-      type: 'dispose_instance',
-      handle,
-      args: [],
+      method: 'dispose_instance',
+      params: {
+        handle,
+      },
     });
   }
 }