Does it work with my AI coding agent?

That's the point. Refactron verifies a diff whoever authored it: Cursor, Claude Code, Copilot, Codex, a codemod, or you. Via MCP your agent can call it before it lands (early access).

What does UNPROVEN mean?

Your tests pass, but the changed lines aren't actually exercised by any test, so “green” proves nothing. We say so explicitly and list the tests to add, instead of hand-waving.

Does my code leave my machine?

No. Refactron runs locally against your real test suite in an isolated shadow tree. Nothing is sent to an external service to make the verdict.

How is this different from just running my tests in CI?

Refactron scopes the run to the blast radius of the change, tells you when the change is uncovered (UNPROVEN), lands atomically only on green, and produces a signed, reproducible record of why it was safe.

What ships today vs. what's coming?

Live today: the SQLAlchemy migration + verification report. Building in the open: the MCP server and the CI gate. Join early access to be a design partner.

All releases

May 15, 2026 · v0.2.0

The Deterministic Rebuild

Refactron rebuilt from the ground up as a 100% deterministic AST engine. No LLM touches your code, and versioning restarts at 0.2.0.

Om Sherikar

A ground-up rebuild

Deterministic engine. Refactron 2.0 is rebuilt as a 100% deterministic AST engine: no LLM touches your code. It supersedes the original Python-implemented 1.x line.
Versioning reset. The rebuild restarts versioning at 0.2.0. Entries from 1.0.15 and below belong to the legacy Python tool.

Major features

10 AST transforms. Five Python (via LibCST) and five TypeScript (via ts-morph), each with cross-file precondition checks.
3-gate verification. Syntax, imports, and your full test suite must pass on a shadow tree before any byte is written: atomic batch write, or nothing.
Documentation engine. The only LLM-touching step, running solely on already-verified diffs. Five providers: Ollama, Groq, OpenAI, Anthropic, and the managed backend.
Configuration and auth. .refactronrc.json via cosmiconfig with schema validation, plus OAuth device-flow login and REFACTRON_TOKEN support.