feat(coding-agent): emit bash_execution_update events (#6971)

packages/coding-agent/docs/rpc.md

@@ -23,7 +23,7 @@ Common options:
 - **Responses**: JSON objects with `type: "response"` indicating command success/failure
 - **Events**: Agent events streamed to stdout as JSON lines
 
-All commands support an optional `id` field for request/response correlation. If provided, the corresponding response will include the same `id`.
+All commands support an optional `id` field for request/response correlation. If provided, the corresponding response will include the same `id`. `bash_execution_update` events also include the `id` of their originating `bash` command.
 
 ### Framing
 
@@ -455,15 +455,18 @@ Response:
 
 #### bash
 
-Execute a shell command and add output to conversation context.
+Execute a shell command and add output to conversation context. Output streams as `bash_execution_update` events while the command runs; the response contains the final result.
 
 ```json
-{"type": "bash", "command": "ls -la"}
+{"id": "req-1", "type": "bash", "command": "ls -la"}
 ```
 
+Include an `id` to associate streamed `bash_execution_update` events with this command.
+
 Response:
 ```json
 {
+  "id": "req-1",
   "type": "response",
   "command": "bash",
   "success": true,
@@ -494,7 +497,7 @@ If output was truncated, includes `fullOutputPath`:
 
 **How bash results reach the LLM:**
 
-The `bash` command executes immediately and returns a `BashResult`. Internally, a `BashExecutionMessage` is created and stored in the agent's message state. This message does NOT emit an event.
+The `bash` command executes immediately and returns a `BashResult`. Internally, a `BashExecutionMessage` is created and stored in the agent's message state.
 
 When the next `prompt` command is sent, all messages (including `BashExecutionMessage`) are transformed before being sent to the LLM. The `BashExecutionMessage` is converted to a `UserMessage` with this format:
 
@@ -509,7 +512,6 @@ drwxr-xr-x ...
 This means:
 1. Bash output is included in the LLM context on the **next prompt**, not immediately
 2. Multiple bash commands can be executed before a prompt; all outputs will be included
-3. No event is emitted for the `BashExecutionMessage` itself
 
 #### abort_bash
 
@@ -829,7 +831,7 @@ Each command has:
 
 ## Events
 
-Events are streamed to stdout as JSON lines during agent operation. Events do NOT include an `id` field (only responses do).
+Events are streamed to stdout as JSON lines during agent operation. Events do not generally include an `id` field; `bash_execution_update` includes the `id` of its originating `bash` command when one was provided.
 
 ### Event Types
 
@@ -843,6 +845,7 @@ Events are streamed to stdout as JSON lines during agent operation. Events do NO
 | `message_start` | Message begins |
 | `message_update` | Streaming update (text/thinking/toolcall deltas) |
 | `message_end` | Message completes |
+| `bash_execution_update` | Direct RPC bash command output chunk |
 | `tool_execution_start` | Tool begins execution |
 | `tool_execution_update` | Tool execution progress (streaming output) |
 | `tool_execution_end` | Tool completes |
@@ -951,6 +954,20 @@ Example streaming a text response:
 {"type":"message_update","message":{...},"assistantMessageEvent":{"type":"text_end","contentIndex":0,"content":"Hello world","partial":{...}}}
 ```
 
+### bash_execution_update
+
+Emitted once for each output chunk from a direct `bash` command. `id` matches the command's `id`, allowing clients to associate output with the correct command.
+
+Events stream all output while the command runs, even if the final `bash` response's `output` is truncated.
+
+```json
+{
+  "type": "bash_execution_update",
+  "id": "req-1",
+  "delta": "total 48\n"
+}
+```
+
 ### tool_execution_start / tool_execution_update / tool_execution_end
 
 Emitted when a tool begins, streams progress, and completes execution.

packages/coding-agent/src/core/agent-session.ts

@@ -176,7 +176,9 @@ export type AgentSessionEvent =
 			source: "compaction";
 			reason: "manual" | "threshold" | "overflow";
 	  }
-	| { type: "summarization_retry_finished" };
+	| { type: "summarization_retry_finished" }
+	| { type: "auto_retry_end"; success: boolean; attempt: number; finalError?: string }
+	| { type: "bash_execution_update"; id?: string; delta: string };
 
 /** Listener function for agent session events */
 export type AgentSessionEventListener = (event: AgentSessionEvent) => void;
@@ -2760,12 +2762,13 @@ export class AgentSession {
 	 * @param command The bash command to execute
 	 * @param onChunk Optional streaming callback for output
 	 * @param options.excludeFromContext If true, command output won't be sent to LLM (!! prefix)
+	 * @param options.id Optional identifier included in bash execution update events
 	 * @param options.operations Custom BashOperations for remote execution
 	 */
 	async executeBash(
 		command: string,
 		onChunk?: (chunk: string) => void,
-		options?: { excludeFromContext?: boolean; operations?: BashOperations },
+		options?: { excludeFromContext?: boolean; id?: string; operations?: BashOperations },
 	): Promise<BashResult> {
 		this._bashAbortController = new AbortController();
 
@@ -2780,7 +2783,10 @@ export class AgentSession {
 				this.sessionManager.getCwd(),
 				options?.operations ?? createLocalBashOperations({ shellPath }),
 				{
-					onChunk,
+					onChunk: (delta) => {
+						onChunk?.(delta);
+						this._emit({ type: "bash_execution_update", id: options?.id, delta });
+					},
 					signal: this._bashAbortController.signal,
 				},
 			);

packages/coding-agent/src/modes/interactive/interactive-mode.ts

@@ -2985,6 +2985,10 @@ export class InteractiveMode {
 				this.ui.requestRender();
 				break;
 
+			case "bash_execution_update":
+				// The bash execution callback handles TUI output rendering.
+				break;
+
 			case "tool_execution_start": {
 				let component = this.pendingTools.get(event.toolCallId);
 				if (!component) {

packages/coding-agent/src/modes/rpc/rpc-mode.ts

@@ -558,6 +558,7 @@ export async function runRpcMode(runtimeHost: AgentSessionRuntime): Promise<neve
 			case "bash": {
 				const result = await session.executeBash(command.command, undefined, {
 					excludeFromContext: command.excludeFromContext,
+					id,
 				});
 				return success(id, "bash", result);
 			}

packages/coding-agent/test/suite/agent-session-bash-persistence.test.ts

@@ -239,4 +239,35 @@ describe("AgentSession bash and persistence characterization", () => {
 		expect(result.output).toContain("hello from custom ops");
 		expect(harness.session.messages[harness.session.messages.length - 1]?.role).toBe("bashExecution");
 	});
+
+	it("streams bash output to the callback and session events", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		const callbackDeltas: string[] = [];
+		const eventUpdates: Array<{ id: string | undefined; delta: string }> = [];
+		const unsubscribe = harness.session.subscribe((event) => {
+			if (event.type === "bash_execution_update") {
+				eventUpdates.push({ id: event.id, delta: event.delta });
+			}
+		});
+		const operations: BashOperations = {
+			exec: async (_command, _cwd, options) => {
+				options.onData(Buffer.from("hello "));
+				options.onData(Buffer.from("world"));
+				return { exitCode: 0 };
+			},
+		};
+
+		await harness.session.executeBash("custom", (delta) => callbackDeltas.push(delta), {
+			id: "bash-1",
+			operations,
+		});
+		unsubscribe();
+
+		expect(callbackDeltas).toEqual(["hello ", "world"]);
+		expect(eventUpdates).toEqual([
+			{ id: "bash-1", delta: "hello " },
+			{ id: "bash-1", delta: "world" },
+		]);
+	});
 });