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+# AGENTS.md
+
+Agent instructions for this repository.
+Generated by [sourcebook](https://github.com/maroondlabs/sourcebook). Review and edit — the best context comes from human + machine together.
+
+## Constraints
+
+These constraints MUST be followed when modifying this codebase:
+
+- **Project structure:** This is a publishable library, not an application. Focus changes on the public API surface. Avoid breaking changes to exported types and function signatures.
+- **Core modules:** Hub files (most depended on): src/flask/globals.py (imported by 24 files); src/flask/helpers.py (imported by 24 files); src/flask/signals.py (imported by 20 files); src/flask/__init__.py (imported by 9 files); src/flask/sansio/scaffold.py (imported by 9 files). Changes here have the widest blast radius.
+- **Circular dependencies:** Circular import chains detected: flask/__init__.py; flask/__init__.py → app.py; flask/__init__.py → app.py → ctx.py. Avoid adding to these cycles.
+
+## Stack
+
+Flask
+
+## Core Modules (by structural importance)
+
+- `src/flask/globals.py`
+- `src/flask/helpers.py`
+- `src/flask/signals.py`
+- `src/flask/__init__.py`
+- `src/flask/json/__init__.py`
+
+## Conventions
+
+- **Testing:** Tests live in a separate test/ directory, mirroring src/ structure. New tests go there, not next to source files.
+- **Python conventions:** Uses __init__.py as barrel exports. Import from the package, not from internal modules.
+- **Dominant patterns:** API endpoints use Flask routes. Follow this pattern for new routes.
+- **Dominant patterns:** Tests use pytest. Test utilities in: tests/test_helpers.py.
+
+## Additional Context
+
+- Most active areas in the last 30 days: .github/ (6 changes). Expect ongoing changes here.
+
+## What to Add Manually
+
+The most valuable context is what only you know. Add:
+
+- Architectural decisions and why they were made
+- Past incidents that shaped current conventions
+- Deprecated patterns to avoid in new code
+- Domain-specific rules or terminology
+- Environment setup beyond what .env.example shows