From 49aa5162bbe87feb27c7a1029b1ba10aeb6f6a84 Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Sat, 21 Feb 2026 02:41:57 +0900
Subject: [PATCH] fix(session-recovery): harden unavailable tool recovery flow

---
 .../detect-error-type.test.ts                 | 22 +++++++++++++++
 .../session-recovery/detect-error-type.ts     |  3 +-
 src/hooks/session-recovery/hook.ts            |  5 ----
 .../recover-unavailable-tool.ts               | 28 +++++++++++--------
 4 files changed, 40 insertions(+), 18 deletions(-)

diff --git a/src/hooks/session-recovery/detect-error-type.test.ts b/src/hooks/session-recovery/detect-error-type.test.ts
index 350ad11b7..de5765c05 100644
--- a/src/hooks/session-recovery/detect-error-type.test.ts
+++ b/src/hooks/session-recovery/detect-error-type.test.ts
@@ -124,6 +124,17 @@ describe("detectErrorType", () => {
     expect(result).toBe("unavailable_tool")
   })
 
+  it("#given a NoSuchToolError token #when detecting #then returns unavailable_tool", () => {
+    //#given
+    const error = { message: "NoSuchToolError: no such tool invalid" }
+
+    //#when
+    const result = detectErrorType(error)
+
+    //#then
+    expect(result).toBe("unavailable_tool")
+  })
+
   it("#given a dummy_tool token in nested error #when detecting #then returns unavailable_tool", () => {
     //#given
     const error = {
@@ -189,4 +200,15 @@ describe("extractUnavailableToolName", () => {
     //#then
     expect(result).toBeNull()
   })
+
+  it("#given no such tool error with colon format #when extracting #then returns tool name", () => {
+    //#given
+    const error = { message: "No such tool: invalid_tool" }
+
+    //#when
+    const result = extractUnavailableToolName(error)
+
+    //#then
+    expect(result).toBe("invalid_tool")
+  })
 })
diff --git a/src/hooks/session-recovery/detect-error-type.ts b/src/hooks/session-recovery/detect-error-type.ts
index 9282a0686..ea9af562a 100644
--- a/src/hooks/session-recovery/detect-error-type.ts
+++ b/src/hooks/session-recovery/detect-error-type.ts
@@ -47,7 +47,7 @@ export function extractMessageIndex(error: unknown): number | null {
 export function extractUnavailableToolName(error: unknown): string | null {
   try {
     const message = getErrorMessage(error)
-    const match = message.match(/unavailable tool ['"]?([^'".\s]+)['"]?/)
+    const match = message.match(/(?:unavailable tool|no such tool)[:\s'"]+([^'".\s]+)/)
     return match ? match[1] : null
   } catch {
     return null
@@ -90,6 +90,7 @@ export function detectErrorType(error: unknown): RecoveryErrorType {
       message.includes("unavailable tool") ||
       message.includes("model tried to call unavailable") ||
       message.includes("nosuchtoolarror") ||
+      message.includes("nosuchtoolerror") ||
       message.includes("no such tool")
     ) {
       return "unavailable_tool"
diff --git a/src/hooks/session-recovery/hook.ts b/src/hooks/session-recovery/hook.ts
index 7335c2dbc..a7a6420f7 100644
--- a/src/hooks/session-recovery/hook.ts
+++ b/src/hooks/session-recovery/hook.ts
@@ -110,11 +110,6 @@ export function createSessionRecoveryHook(ctx: PluginInput, options?: SessionRec
         success = await recoverToolResultMissing(ctx.client, sessionID, failedMsg)
       } else if (errorType === "unavailable_tool") {
         success = await recoverUnavailableTool(ctx.client, sessionID, failedMsg)
-        if (success && experimental?.auto_resume) {
-          const lastUser = findLastUserMessage(msgs ?? [])
-          const resumeConfig = extractResumeConfig(lastUser, sessionID)
-          await resumeSession(ctx.client, resumeConfig)
-        }
       } else if (errorType === "thinking_block_order") {
         success = await recoverThinkingBlockOrder(ctx.client, sessionID, failedMsg, ctx.directory, info.error)
         if (success && experimental?.auto_resume) {
diff --git a/src/hooks/session-recovery/recover-unavailable-tool.ts b/src/hooks/session-recovery/recover-unavailable-tool.ts
index e72eeefbc..193f61e68 100644
--- a/src/hooks/session-recovery/recover-unavailable-tool.ts
+++ b/src/hooks/session-recovery/recover-unavailable-tool.ts
@@ -7,6 +7,17 @@ import { isSqliteBackend } from "../../shared/opencode-storage-detection"
 
 type Client = ReturnType<typeof createOpencodeClient>
 
+interface ToolResultPart {
+  type: "tool_result"
+  tool_use_id: string
+  content: string
+}
+
+interface PromptWithToolResultInput {
+  path: { id: string }
+  body: { parts: ToolResultPart[] }
+}
+
 interface ToolUsePart {
   type: "tool_use"
   id: string
@@ -80,23 +91,16 @@ export async function recoverUnavailableTool(
   const toolResultParts = targetToolUses.map((part) => ({
     type: "tool_result" as const,
     tool_use_id: part.id,
-    content: {
-      status: "error",
-      error: "Tool not available. Please continue without this tool.",
-    },
+    content: '{"status":"error","error":"Tool not available. Please continue without this tool."}',
   }))
 
   try {
-    const promptAsyncKey = ["prompt", "Async"].join("")
-    const promptAsync = Reflect.get(client.session, promptAsyncKey)
-    if (typeof promptAsync !== "function") {
-      return false
-    }
-
-    await promptAsync({
+    const promptInput: PromptWithToolResultInput = {
       path: { id: sessionID },
       body: { parts: toolResultParts },
-    })
+    }
+    const promptAsync = client.session.promptAsync as (...args: never[]) => unknown
+    await Reflect.apply(promptAsync, client.session, [promptInput])
     return true
   } catch {
     return false