fix(plugin): normalize event session ids

Handle OpenCode session events that carry the session ID under properties.info.id or properties.info.sessionID so background tasks and continuation hooks do not miss idle/error/delete events.

Add regression coverage for nested session.idle events completing background tasks and waking continuation hooks.

src/hooks/ralph-loop/index.test.ts

@@ -304,6 +304,25 @@ describe("ralph-loop", () => {
       expect(state?.iteration).toBe(2)
     })
 
+    test("should inject continuation when idle event carries session id in info", async () => {
+      // given - active loop state and nested session event shape
+      const hook = createRalphLoopHook(createMockPluginInput())
+      hook.startLoop("session-info-idle", "Build a feature", { maxIterations: 10 })
+
+      // when - session goes idle with id under info
+      await hook.event({
+        event: {
+          type: "session.idle",
+          properties: { info: { id: "session-info-idle" } },
+        },
+      })
+
+      // then - continuation should be injected for that session
+      expect(promptCalls.length).toBe(1)
+      expect(promptCalls[0].sessionID).toBe("session-info-idle")
+      expect(promptCalls[0].text).toContain("RALPH LOOP")
+    })
+
     test("should settle idle before injecting continuation", async () => {
       // given - active loop state with a configured idle settle delay
       const hook = createRalphLoopHook(createMockPluginInput(), { idleSettleMs: 25 })

src/hooks/ralph-loop/non-abort-error-continuation.test.ts

@@ -213,6 +213,77 @@ describe("ralph-loop non-abort error continuation", () => {
 		expect(hook.getState()?.iteration).toBe(3)
 	})
 
+	test("continues after retry run activity from legacy message.part.updated part session id", async () => {
+		// given - an active loop retries a recoverable runtime error
+		const hook = createRalphLoopHook({
+			directory: testDirectory,
+			project: testDirectory,
+			worktree: testDirectory,
+			serverUrl: "http://localhost:4096",
+			$: async () => ({}),
+			client: {
+				session: {
+					messages: async (options: { path: { id: string } }) => {
+						messagesCalls.push({ sessionID: options.path.id })
+						return { data: [] }
+					},
+					promptAsync: async (options: {
+						path: { id: string }
+						body: { parts: Array<{ type: string; text: string }> }
+					}) => {
+						promptCalls.push({
+							sessionID: options.path.id,
+							text: options.body.parts[0]?.text ?? "",
+						})
+						return {}
+					},
+					prompt: async () => ({}),
+				},
+				tui: {
+					showToast: async () => ({}),
+				},
+			},
+		} as never)
+
+		hook.startLoop("session-123", "Keep working", {
+			messageCountAtStart: 0,
+			maxIterations: 5,
+		})
+
+		await hook.event({
+			event: {
+				type: "session.error",
+				properties: {
+					sessionID: "session-123",
+					error: { name: "RuntimeError" },
+				},
+			},
+		})
+
+		// when - the retried run emits legacy assistant activity before any stale idle
+		await hook.event({
+			event: {
+				type: "message.part.updated",
+				properties: {
+					part: {
+						id: "part-1",
+						messageID: "msg-1",
+						sessionID: "session-123",
+						type: "text",
+						text: "working",
+					},
+				},
+			},
+		})
+		await hook.event({
+			event: { type: "session.idle", properties: { sessionID: "session-123" } },
+		})
+
+		// then - the real idle is allowed to continue the loop
+		expect(promptCalls).toHaveLength(2)
+		expect(hook.getState()?.iteration).toBe(3)
+	})
+
 	test("skips immediate runtime retry while background tasks are running", async () => {
 		// given - an active loop owns running background work
 		const hook = createRalphLoopHook({

src/hooks/ralph-loop/ralph-loop-event-handler.ts

@@ -1,5 +1,6 @@
 import type { PluginInput } from "@opencode-ai/plugin"
 import { log } from "../../shared/logger"
+import { resolveMessageEventSessionID, resolveSessionEventID } from "../../shared/event-session-id"
 import type { RalphLoopOptions, RalphLoopState } from "./types"
 import { HOOK_NAME } from "./constants"
 import { handleDetectedCompletion } from "./completion-handler"
@@ -36,12 +37,6 @@ function hasRunningBackgroundTasks(
 		: false
 }
 
-function getInfoSessionID(props: Record<string, unknown> | undefined): string | undefined {
-	const info = props?.info as Record<string, unknown> | undefined
-	const sessionID = info?.sessionID
-	return typeof sessionID === "string" ? sessionID : undefined
-}
-
 function getRuntimeRetryActivitySessionID(
 	eventType: string,
 	props: Record<string, unknown> | undefined,
@@ -49,20 +44,19 @@ function getRuntimeRetryActivitySessionID(
 	if (eventType === "message.updated") {
 		const info = props?.info as Record<string, unknown> | undefined
 		const role = info?.role
-		return role === "assistant" ? getInfoSessionID(props) : undefined
+		return role === "assistant" ? resolveMessageEventSessionID(props) : undefined
 	}
 
 	if (eventType === "message.part.updated") {
-		if (typeof props?.sessionID === "string") return props.sessionID
-		return getInfoSessionID(props)
+		return resolveMessageEventSessionID(props)
 	}
 
 	if (eventType === "message.part.delta") {
-		return typeof props?.sessionID === "string" ? props.sessionID : undefined
+		return resolveMessageEventSessionID(props)
 	}
 
 	if (eventType === "tool.execute.before" || eventType === "tool.execute.after") {
-		return typeof props?.sessionID === "string" ? props.sessionID : undefined
+		return resolveMessageEventSessionID(props)
 	}
 
 	return undefined
@@ -198,7 +192,7 @@ export function createRalphLoopEventHandler(
 		}
 
 		if (event.type === "session.idle") {
-			const sessionID = props?.sessionID as string | undefined
+			const sessionID = resolveSessionEventID(props)
 			if (!sessionID) return
 
 			if (inFlightSessions.has(sessionID)) {
@@ -389,7 +383,7 @@ export function createRalphLoopEventHandler(
 		}
 
 		if (event.type === "session.error") {
-			const sessionID = props?.sessionID as string | undefined
+			const sessionID = resolveSessionEventID(props)
 			const error = props?.error
 			if (!sessionID || isAbortError(error)) {
 				handleErroredLoopSession(props, options.loopState)

src/hooks/ralph-loop/session-event-handler.ts

@@ -1,4 +1,5 @@
 import { log } from "../../shared/logger"
+import { resolveSessionEventID } from "../../shared/event-session-id"
 import { HOOK_NAME } from "./constants"
 import type { RalphLoopState } from "./types"
 
@@ -11,13 +12,13 @@ export function handleDeletedLoopSession(
 	props: Record<string, unknown> | undefined,
 	loopState: LoopStateController,
 ): boolean {
-	const sessionInfo = props?.info as { id?: string } | undefined
-	if (!sessionInfo?.id) return false
+	const sessionID = resolveSessionEventID(props)
+	if (!sessionID) return false
 
 	const state = loopState.getState()
-	if (state?.session_id === sessionInfo.id) {
+	if (state?.session_id === sessionID) {
 		loopState.clear()
-		log(`[${HOOK_NAME}] Session deleted, loop cleared`, { sessionID: sessionInfo.id })
+		log(`[${HOOK_NAME}] Session deleted, loop cleared`, { sessionID })
 	}
 	return true
 }
@@ -26,7 +27,7 @@ export function handleErroredLoopSession(
 	props: Record<string, unknown> | undefined,
 	loopState: LoopStateController,
 ): boolean {
-	const sessionID = props?.sessionID as string | undefined
+	const sessionID = resolveSessionEventID(props)
 	const error = props?.error as { name?: string } | undefined
 
 	if (error?.name === "MessageAbortedError") {