Sentry Bug Fixer

Automated bug fixing using Claude Code and Sentry MCP integration. This GitLab CI template periodically fetches unresolved issues from Sentry, uses AI to analyze and fix them, and creates merge requests automatically.

How It Works

Scheduled Trigger: Pipeline runs on a schedule (e.g., every 6 hours)
Issue Discovery: Claude queries Sentry MCP for unresolved issues
Analysis: For each issue, Claude:
- Gets full stack trace from Sentry
- Uses Seer AI for root cause analysis
- Reads relevant source files
Fix Implementation: Claude edits files to fix the bug
MR Creation: Changes are committed, pushed, and an MR is created via GitLab MCP
Human Review: Developers review and merge the automated MRs

Quick Start

1. Set Up Group-Level Variables

In your GitLab Group settings: Settings → CI/CD → Variables

Variable	Type	Description
`GCP_WORKLOAD_IDENTITY_PROVIDER`	Regular	GCP Workload Identity Provider resource name
`GCP_SERVICE_ACCOUNT`	Regular	GCP Service Account email for Vertex AI
`GCP_PROJECT_ID`	Regular	GCP Project ID with Vertex AI enabled
`CLOUD_ML_REGION`	Regular	Vertex AI region (default: `europe-west4` )
`SENTRY_AUTH_TOKEN`	Masked, Protected	Sentry access token with read permissions
`SENTRY_ORG_SLUG`	Regular	Your Sentry organization slug

2. Configure GCP Workload Identity Federation

Set up OIDC trust between GitLab and GCP:

Create a Workload Identity Pool in GCP
Add GitLab as an OIDC provider
Grant the service account
```
aiplatform.user
```
role for Vertex AI

2. Include Template in Your Project

Add to your project's

.gitlab-ci.yml

stages:
  - build
  - test
  - bugfix  # Add this stage

include:
  - project: 'your-group/sentry-bugfixer'
    file: '/bugfixer.yml'
    ref: main

sentry-bugfix:
  extends: .sentry-bugfix

3. Create a Pipeline Schedule

In your project: CI/CD → Schedules → New schedule

Setting	Value
Description	Sentry Bug Fixer
Interval	`0 /6 * *` (every 6 hours)
Target branch	main

Configuration

Variables

Override these variables in your project's job definition:

Variable	Default	Description
`SENTRY_PROJECT_SLUG`	`$CI_PROJECT_NAME`	Sentry project to query (defaults to GitLab project name)
`MAX_ISSUES`	`5`	Maximum issues to process per run

Example with Custom Configuration

sentry-bugfix:
  extends: .sentry-bugfix
  variables:
    SENTRY_PROJECT_SLUG: "my-custom-sentry-project"
    MAX_ISSUES: "3"

Project-Specific Context (Optional)

Create a

CLAUDE.md

file in your project root to provide context:

# Project Context

## Tech Stack
- Language: TypeScript
- Framework: Next.js
- Testing: Jest + React Testing Library

## Code Standards
- Use TypeScript strict mode
- Follow existing patterns in the codebase
- Add tests for bug fixes when possible

## Build & Test Commands
- Run tests: `npm test`
- Type check: `npm run typecheck`
- Lint: `npm run lint`

Security

Job Isolation: Each job runs in a fresh, isolated container
No persistent state: Environment is destroyed after each run
MR-based changes: All fixes go through merge requests for review
Branch protection: Your existing protection rules still apply
Masked variables: Secrets are never exposed in job logs

Deduplication

The system prevents duplicate MRs through:

Branch naming: Uses
```
bugfix/sentry-{ISSUE_ID}
```
pattern
Claude instructions: Skips issues with existing MRs/branches
Sentry issue ID: Each issue only gets one fix attempt

Troubleshooting

Issue	Solution
Job times out	Reduce `MAX_ISSUES` or increase timeout
Claude can't access Sentry	Check `SENTRY_AUTH_TOKEN` is valid and masked
MRs not being created	Ensure runner has git push permissions
Fixes don't compile	Add CLAUDE.md with build/test instructions
Too many MRs	Reduce schedule frequency or `MAX_ISSUES`

Cost Considerations

GitLab CI minutes: ~30-60 min per run depending on issue count
Claude API: Variable based on codebase size and issue complexity
Recommendation: Start with
```
MAX_ISSUES=1
```
to test, then increase

Manual Trigger

You can manually trigger the bugfix job from:

CI/CD → Pipelines → Run pipeline (select branch, run)
The job only runs on
```
schedule
```
or
```
web
```
(manual) triggers

Requirements

GitLab 14.0+ (for
```
include
```
with
```
project
```
)
Node.js 24+ (used in the job image)
Sentry project with unresolved issues
Anthropic API access

License

MIT