feat(hooks): add json-error-recovery hook to prevent infinite retry loops

src/config/schema/hooks.ts

@@ -33,6 +33,7 @@ export const HookNameSchema = z.enum([
   "claude-code-hooks",
   "auto-slash-command",
   "edit-error-recovery",
+  "json-error-recovery",
   "delegate-task-retry",
   "prometheus-md-only",
   "sisyphus-junior-notepad",

src/hooks/index.ts

@@ -29,6 +29,7 @@ export { createCategorySkillReminderHook } from "./category-skill-reminder";
 export { createRalphLoopHook, type RalphLoopHook } from "./ralph-loop";
 export { createAutoSlashCommandHook } from "./auto-slash-command";
 export { createEditErrorRecoveryHook } from "./edit-error-recovery";
+export { createJsonErrorRecoveryHook } from "./json-error-recovery";
 export { createPrometheusMdOnlyHook } from "./prometheus-md-only";
 export { createSisyphusJuniorNotepadHook } from "./sisyphus-junior-notepad";
 export { createTaskResumeInfoHook } from "./task-resume-info";

src/hooks/json-error-recovery/hook.ts

@@ -0,0 +1,41 @@
+import type { PluginInput } from "@opencode-ai/plugin"
+
+export const JSON_ERROR_PATTERNS = [
+  "json parse error",
+  "syntaxerror: unexpected token",
+  "expected '}'",
+  "unexpected eof",
+] as const
+
+export const JSON_ERROR_REMINDER = `
+[JSON PARSE ERROR - IMMEDIATE ACTION REQUIRED]
+
+You sent invalid JSON arguments. The system could not parse your tool call.
+STOP and do this NOW:
+
+1. LOOK at the error message above to see what was expected vs what you sent.
+2. CORRECT your JSON syntax (missing braces, unescaped quotes, trailing commas, etc).
+3. RETRY the tool call with valid JSON.
+
+DO NOT repeat the exact same invalid call.
+`
+
+export function createJsonErrorRecoveryHook(_ctx: PluginInput) {
+  return {
+    "tool.execute.after": async (
+      _input: { tool: string; sessionID: string; callID: string },
+      output: { title: string; output: string; metadata: unknown }
+    ) => {
+      if (typeof output.output !== "string") return
+
+      const outputLower = output.output.toLowerCase()
+      const hasJsonError = JSON_ERROR_PATTERNS.some((pattern) =>
+        outputLower.includes(pattern)
+      )
+
+      if (hasJsonError) {
+        output.output += `\n${JSON_ERROR_REMINDER}`
+      }
+    },
+  }
+}

src/hooks/json-error-recovery/index.test.ts

@@ -0,0 +1,65 @@
+import { beforeEach, describe, expect, it } from "bun:test"
+
+import {
+  createJsonErrorRecoveryHook,
+  JSON_ERROR_PATTERNS,
+  JSON_ERROR_REMINDER,
+} from "./index"
+
+describe("createJsonErrorRecoveryHook", () => {
+  let hook: ReturnType<typeof createJsonErrorRecoveryHook>
+
+  beforeEach(() => {
+    hook = createJsonErrorRecoveryHook({} as any)
+  })
+
+  describe("tool.execute.after", () => {
+    const createInput = () => ({
+      tool: "Read",
+      sessionID: "test-session",
+      callID: "test-call-id",
+    })
+
+    const createOutput = (outputText: string) => ({
+      title: "Tool Error",
+      output: outputText,
+      metadata: {},
+    })
+
+    it("appends reminder when output includes JSON parse error", async () => {
+      const input = createInput()
+      const output = createOutput("JSON Parse error: Expected '}'")
+
+      await hook["tool.execute.after"](input, output)
+
+      expect(output.output).toContain(JSON_ERROR_REMINDER)
+    })
+
+    it("appends reminder when output includes SyntaxError", async () => {
+      const input = createInput()
+      const output = createOutput("SyntaxError: Unexpected token in JSON at position 10")
+
+      await hook["tool.execute.after"](input, output)
+
+      expect(output.output).toContain(JSON_ERROR_REMINDER)
+    })
+
+    it("does not append reminder for normal output", async () => {
+      const input = createInput()
+      const output = createOutput("Task completed successfully")
+
+      await hook["tool.execute.after"](input, output)
+
+      expect(output.output).toBe("Task completed successfully")
+    })
+  })
+
+  describe("JSON_ERROR_PATTERNS", () => {
+    it("contains known parse error patterns", () => {
+      expect(JSON_ERROR_PATTERNS).toContain("json parse error")
+      expect(JSON_ERROR_PATTERNS).toContain("syntaxerror: unexpected token")
+      expect(JSON_ERROR_PATTERNS).toContain("expected '}'")
+      expect(JSON_ERROR_PATTERNS).toContain("unexpected eof")
+    })
+  })
+})

src/hooks/json-error-recovery/index.ts

@@ -0,0 +1,5 @@
+export {
+  createJsonErrorRecoveryHook,
+  JSON_ERROR_PATTERNS,
+  JSON_ERROR_REMINDER,
+} from "./hook"

src/plugin/hooks/create-session-hooks.ts

@@ -13,6 +13,7 @@ import {
   createInteractiveBashSessionHook,
   createRalphLoopHook,
   createEditErrorRecoveryHook,
+  createJsonErrorRecoveryHook,
   createDelegateTaskRetryHook,
   createTaskResumeInfoHook,
   createStartWorkHook,
@@ -43,6 +44,7 @@ export type SessionHooks = {
   interactiveBashSession: ReturnType<typeof createInteractiveBashSessionHook> | null
   ralphLoop: ReturnType<typeof createRalphLoopHook> | null
   editErrorRecovery: ReturnType<typeof createEditErrorRecoveryHook> | null
+  jsonErrorRecovery: ReturnType<typeof createJsonErrorRecoveryHook> | null
   delegateTaskRetry: ReturnType<typeof createDelegateTaskRetryHook> | null
   startWork: ReturnType<typeof createStartWorkHook> | null
   prometheusMdOnly: ReturnType<typeof createPrometheusMdOnlyHook> | null
@@ -130,6 +132,10 @@ export function createSessionHooks(args: {
     ? safeHook("edit-error-recovery", () => createEditErrorRecoveryHook(ctx))
     : null
 
+  const jsonErrorRecovery = isHookEnabled("json-error-recovery")
+    ? safeHook("json-error-recovery", () => createJsonErrorRecoveryHook(ctx))
+    : null
+
   const delegateTaskRetry = isHookEnabled("delegate-task-retry")
     ? safeHook("delegate-task-retry", () => createDelegateTaskRetryHook(ctx))
     : null
@@ -166,6 +172,7 @@ export function createSessionHooks(args: {
     interactiveBashSession,
     ralphLoop,
     editErrorRecovery,
+    jsonErrorRecovery,
     delegateTaskRetry,
     startWork,
     prometheusMdOnly,

src/plugin/tool-execute-after.ts

@@ -40,6 +40,7 @@ export function createToolExecuteAfterHandler(args: {
     await hooks.categorySkillReminder?.["tool.execute.after"]?.(input, output)
     await hooks.interactiveBashSession?.["tool.execute.after"]?.(input, output)
     await hooks.editErrorRecovery?.["tool.execute.after"]?.(input, output)
+    await hooks.jsonErrorRecovery?.["tool.execute.after"]?.(input, output)
     await hooks.delegateTaskRetry?.["tool.execute.after"]?.(input, output)
     await hooks.atlasHook?.["tool.execute.after"]?.(input, output)
     await hooks.taskResumeInfo?.["tool.execute.after"]?.(input, output)