Claude Code / AI Coding Tools

Claude Code /goal Stop Hook JSON Validation Failed — Fix Goal Auto-Clear

Fix Claude Code /goal Stop hook failing with JSON validation error preventing auto-goal clearance Includes evidence for Claude Code troubleshooting demand.

Source-backed Last updated May 13, 2026 1 source Needs local verification

Category: AI Coding Tools
Error signature: Stop hook error: JSON validation failed
Quick fix: Compare the failing environment with a known working setup, then change one configuration value at a time.
Updated: May 13, 2026
Verification status: Source-backed
Evidence: 1 public source URL

Before you change production

This page includes public source URLs in the imported troubleshooting record. Compare those references with your version and environment before applying changes.

Reproduce the smallest failing action and save non-secret logs before changing configuration.
Check versions for Claude Code, related SDKs, package managers, CI runners, and hosting providers.
Change one setting or dependency at a time, then rerun the same failing command or request.
Avoid destructive commands, credential rotation, billing changes, or security relaxations without a rollback plan.

What this error means

Stop hook error: JSON validation failed is a Claude Code failure pattern reported for developers trying to fix claude code /goal stop hook failing with json validation error preventing auto-goal clearance. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub issue #58558 filed 2026-05-13 documents the /goal Stop hook rejecting markdown-fenced JSON output. The hook runs Claude as subprocess, which outputs JSON in code fences. Validator rejects it despite structurally valid JSON. Results in: (1) error shown every turn, (2) goal never auto-cleared, (3) requires manual /goal clear.

Common causes

The /goal feature's Stop hook rejects valid JSON output wrapped in markdown code fences, showing 'Stop hook error: JSON validation failed' every turn end. Goals never auto-clear, forcing manual /goal clear commands. This breaks the documented auto-complete workflow for task-oriented sessions.
GitHub issue #58558 filed 2026-05-13 documents the /goal Stop hook rejecting markdown-fenced JSON output. The hook runs Claude as subprocess, which outputs JSON in code fences. Validator rejects it despite structurally valid JSON. Results in: (1) error shown every turn, (2) goal never auto-cleared, (3) requires manual /goal clear.

Quick fixes

Confirm the exact error signature matches Stop hook error: JSON validation failed.
Check the Claude Code account, local tool state, and provider configuration involved in the failing workflow.
Compare the failing environment with a known working setup, then change one configuration value at a time.

Platform/tool-specific checks

Verify the command, editor, extension, or API client that produced the error.
Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

Capture the exact error message and the command, editor action, or request that triggered it.
Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
Review the source evidence below and compare it with your environment.
Apply one change at a time and rerun the smallest failing action.
Keep the working fix documented for the team or deployment environment.

How to prevent it

Keep provider/tool configuration documented.
Record non-secret diagnostics such as tool version, provider name, model name, and command path.
Add a lightweight check before CI or production workflows depend on the tool.

Diagnostic flow for this page

Match Stop hook error: JSON validation failed exactly before applying the quick fix.
Compare the failing environment with Claude Code versions, account scope, provider settings, and deployment context.
Check the listed common causes in order, starting with the cause that best matches your logs.
Use the evidence status below to decide whether to confirm against public sources or official documentation.
Apply one reversible change, rerun the smallest failing action, and keep rollback notes.

FAQ

What does Stop hook error: JSON validation failed mean in Claude Code?

Stop hook error: JSON validation failed indicates the workflow described by "Claude Code /goal Stop Hook JSON Validation Failed — Fix Goal Auto-Clear" failed in a AI Coding Tools context. Start by confirming the exact signature and the component that emitted it.

What should I check first for Stop hook error: JSON validation failed?

Check whether this cause matches your environment: The /goal feature's Stop hook rejects valid JSON output wrapped in markdown code fences, showing 'Stop hook error: JSON validation failed' every turn end. Goals never auto-clear, forcing manual /goal clear commands. This breaks the documented auto-complete workflow for task-oriented sessions.

Is the Stop hook error: JSON validation failed guidance source-backed?

The "Claude Code /goal Stop Hook JSON Validation Failed — Fix Goal Auto-Clear" page is labeled source-backed. It has 1 public source URL from github.com, so use that evidence status when deciding how much additional verification you need.

When should I avoid the quick fix for Stop hook error: JSON validation failed?

For "Claude Code /goal Stop Hook JSON Validation Failed — Fix Goal Auto-Clear", avoid applying "Compare the failing environment with a known working setup, then change one configuration value at a time." when the error text differs, the affected version or provider is different, or the change would touch credentials, billing, DNS, production deploy settings, or irreversible data.

What should I collect before debugging Stop hook error: JSON validation failed?

For "Claude Code /goal Stop Hook JSON Validation Failed — Fix Goal Auto-Clear", collect the failing Claude Code command or request, non-secret configuration, versions, timestamps, request IDs when available, and the smallest reproduction that still triggers the signature.