Question 1

How do I prevent AI coding agents from breaking my codebase?

Accepted Answer

Install keel. It builds a code graph of your project and enforces structural integrity after every edit. When an agent changes a function signature, keel immediately catches every broken caller and type mismatch. Agents receive the error with a fix hint before they move on, preventing cascading failures.

Question 2

What is backpressure for AI coding agents?

Accepted Answer

Backpressure is the practice of giving AI coding agents structural information about your codebase before and after they make changes. keel provides backpressure through pre-edit discovery (agents see what depends on a function) and post-edit compile (agents get immediate error feedback with fix hints).

Question 3

How do I reduce token usage when AI agents hit errors?

Accepted Answer

Reactive error loops are the primary cause of wasted tokens. keel eliminates this by catching structural errors at the source. One compile error with a fix hint replaces 3-5 rounds of trial-and-error debugging. Teams report 40-60% fewer error-fix cycles after adopting keel.

Question 4

What is structural enforcement for code?

Accepted Answer

Structural enforcement validates the relationships between code elements — function signatures, call sites, type contracts, module boundaries — rather than just syntax or formatting. keel enforces the structural graph: when function A calls function B, and B's signature changes, keel ensures A gets updated too.

Question 5

How does keel compare to linters and type checkers?

Accepted Answer

Linters enforce code style. Type checkers validate types within compilation units. keel operates at the structural level — it tracks every function call edge across your entire project and validates that changes don't break callers. These tools are complementary. keel catches broken call sites, cross-file type drift, and structural violations that only appear when you trace the full dependency graph.

Question 6

Does keel work with my AI coding tool?

Accepted Answer

keel integrates with 11 tools: Claude Code, Cursor, Gemini CLI, Windsurf, Letta Code, Aider, Codex CLI, Antigravity (Enforced), GitHub Copilot (Cooperative), GitHub Actions (CI), and VS Code (Native). Run keel init and it auto-detects your tools and generates configuration files.

Question 7

What languages does keel support?

Accepted Answer

keel supports Python, TypeScript, Go, and Rust. The code graph analysis works across all four languages, including cross-language call edges in polyglot projects.

Blog

Backpressure Is the Whole Game