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

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"