fix: adapt before_agent_start prompt extraction and child process detection for modern Pi

.github/workflows/ci.yml

@@ -58,7 +58,7 @@ jobs:
         with:
           ref: ${{ inputs.ref || github.sha }}
           persist-credentials: false
-      - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
+      - uses: actions/setup-node@949feb2413d6458794dcd2491c4babbbce0c15c1 # v7.1.0
         with:
           node-version: ${{ matrix.node }}
           cache: npm
@@ -79,7 +79,7 @@ jobs:
         with:
           ref: ${{ inputs.ref || github.sha }}
           persist-credentials: false
-      - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
+      - uses: actions/setup-node@949feb2413d6458794dcd2491c4babbbce0c15c1 # v7.1.0
         with:
           node-version: '24'
           cache: npm
@@ -105,7 +105,7 @@ jobs:
         with:
           ref: ${{ inputs.ref || github.sha }}
           persist-credentials: false
-      - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
+      - uses: actions/setup-node@949feb2413d6458794dcd2491c4babbbce0c15c1 # v7.1.0
         with:
           node-version: '24'
           cache: npm
@@ -124,15 +124,15 @@ jobs:
         with:
           ref: ${{ inputs.ref || github.sha }}
           persist-credentials: false
-      - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
+      - uses: actions/setup-node@949feb2413d6458794dcd2491c4babbbce0c15c1 # v7.1.0
         with:
           node-version: '24'
           cache: npm
       - run: npm ci --ignore-scripts
       - run: npm run build
       - id: name
         run: echo "artifact=package-${GITHUB_RUN_ID}-${GITHUB_RUN_ATTEMPT}" >> "$GITHUB_OUTPUT"
-      - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+      - uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2
         with:
           name: ${{ steps.name.outputs.artifact }}
           path: dist/

.github/workflows/release.yml

@@ -109,12 +109,12 @@ jobs:
           # The publishing tools come from this trusted main workflow, not an artifact.
           ref: ${{ github.sha }}
           persist-credentials: false
-      - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
+      - uses: actions/setup-node@949feb2413d6458794dcd2491c4babbbce0c15c1 # v7.1.0
         with:
           node-version: '24'
           registry-url: https://registry.npmjs.org
           package-manager-cache: false
-      - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+      - uses: actions/download-artifact@9000827ccba6bdab643e8b6fd33ac0654aef8333 # v8.0.2
         with:
           name: ${{ needs.verify.outputs.artifact }}
           path: dist

package.json

@@ -60,9 +60,13 @@
 	},
 	"devDependencies": {
 		"@earendil-works/pi-coding-agent": "0.85.1",
-		"@types/node": "22.20.2",
-		"typebox": "1.3.31",
+		"@types/node": "22.20.5",
+		"typebox": "1.3.34",
 		"typescript": "7.0.2",
 		"yaml": "2.9.1"
+	},
+	"overrides": {
+		"brace-expansion": "^5.0.12",
+		"undici": "^8.10.2"
 	}
 }

src/child-process.test.ts

@@ -14,8 +14,21 @@ describe("isSubagentProcess", () => {
 		);
 	});
 
+	test("returns true when PI_SUBAGENT_CHILD is set to 1", () => {
+		assert.equal(isSubagentProcess({ PI_SUBAGENT_CHILD: "1" }), true);
+	});
+
+	test("returns false when PI_SUBAGENT_CHILD is set to 0", () => {
+		assert.equal(isSubagentProcess({ PI_SUBAGENT_CHILD: "0" }), false);
+	});
+
+	test("returns true when PI_SUBAGENT_RUNNER_PID is set", () => {
+		assert.equal(isSubagentProcess({ PI_SUBAGENT_RUNNER_PID: "4321" }), true);
+	});
+
 	test("returns false when the subagent env var is an empty string", () => {
 		assert.equal(isSubagentProcess({ PI_SUBAGENT_AGENT_ID: "" }), false);
+		assert.equal(isSubagentProcess({ PI_SUBAGENT_RUNNER_PID: "" }), false);
 	});
 
 	test("ignores unrelated env vars", () => {

src/child-process.ts

@@ -1,8 +1,19 @@
-/** Environment variable set by run-subagent on child agent processes. */
+/**
+ * Environment variables set on child agent processes:
+ * - PI_SUBAGENT_AGENT_ID: Legacy runner identification.
+ * - PI_SUBAGENT_CHILD: Modern pi-subagents standard (set to "1").
+ * - PI_SUBAGENT_RUNNER_PID: Detached background runner process.
+ */
 const SUBAGENT_AGENT_ID_ENV = "PI_SUBAGENT_AGENT_ID";
+const SUBAGENT_CHILD_ENV = "PI_SUBAGENT_CHILD";
+const SUBAGENT_RUNNER_PID_ENV = "PI_SUBAGENT_RUNNER_PID";
 
 /** Returns true when the current process is a child subagent process. */
 export function isSubagentProcess(env: NodeJS.ProcessEnv): boolean {
 	const agentId = env[SUBAGENT_AGENT_ID_ENV];
-	return agentId !== undefined && agentId !== "";
+	if (agentId !== undefined && agentId !== "") return true;
+	if (env[SUBAGENT_CHILD_ENV] === "1") return true;
+	const runnerPid = env[SUBAGENT_RUNNER_PID_ENV];
+	if (runnerPid !== undefined && runnerPid !== "") return true;
+	return false;
 }

src/index.test.ts

@@ -29,6 +29,21 @@ test('factory has no filesystem writes; five relevant hooks, no approval/signal
 test('subagent factory registers nothing and never creates state',()=>fixture(async({stateDir,hooks})=>{
 	assert.equal(hooks.size,0);assert.equal(existsSync(stateDir),false);
 },undefined,{PI_SUBAGENT_AGENT_ID:'child'}));
+test('subagent factory registers nothing when PI_SUBAGENT_CHILD or PI_SUBAGENT_RUNNER_PID is set',async()=>{
+	await fixture(async({hooks})=>{ assert.equal(hooks.size,0); },undefined,{PI_SUBAGENT_CHILD:'1'});
+	await fixture(async({hooks})=>{ assert.equal(hooks.size,0); },undefined,{PI_SUBAGENT_RUNNER_PID:'9999'});
+});
+test('before_agent_start handles missing prompt, custom messages and content-block arrays safely',()=>fixture(async({call})=>{
+	await call('session_compact',compact());
+	// Custom message without prompt property
+	assert.equal(await call('before_agent_start',{messageType:'custom',message:{role:'user',content:'test'},systemPrompt:'Base'}),undefined);
+	// Undefined / empty prompt
+	assert.equal(await call('before_agent_start',{prompt:'',systemPrompt:'Base'}),undefined);
+	assert.equal(await call('before_agent_start',{systemPrompt:'Base'}),undefined);
+	// Array content blocks
+	const arrayResult = await call('before_agent_start',{prompt:[{type:'text',text:'Database port'}],systemPrompt:'Base prompt'});
+	assert.match(arrayResult.systemPrompt,/5432/);
+}));
 test('compaction automatically persists and recall follows the topic across directories and sessions',()=>fixture(async({stateDir,call,ctx})=>{
 	await call('session_compact',compact());
 	const result=await call('before_agent_start',{prompt:'Database port',systemPrompt:'Base prompt'});

src/index.ts

@@ -168,8 +168,13 @@ export default async function memoryEvolution(pi: ExtensionAPI, dependencies: Me
 		if (captured) void enqueue(id, ctx);
 	}));
 	pi.on("before_agent_start", guard((event, ctx) => {
+		const rawPrompt = 'prompt' in event ? event.prompt : undefined;
+		const promptText = typeof rawPrompt === 'string' ? rawPrompt
+			: Array.isArray(rawPrompt) ? (rawPrompt as { type?: string; text?: string }[]).filter(b => b?.type === 'text' && typeof b?.text === 'string').map(b => b.text).join('\n')
+			: '';
+		if (!promptText.trim()) return;
 		lastRecall = 'Last automatic recall failed before completing; see /memory status.';
-		const query = resolveRecallQuery(event.prompt, recentUserMessages(ctx));
+		const query = resolveRecallQuery(promptText, recentUserMessages(ctx));
 		const { selected, diagnostics } = retrieveMemories(query.query ? getStore().readMemories() : [], query);
 		const digest = buildRuntimeDigest(selected, query);
 		lastRecall = diagnosticText({ ...diagnostics, injected: digest?.split('\n').filter(line => line.startsWith('{')).length ?? 0,