Building Phonton: a local-first AI coding CLI that verifies diffs before review

I have been building Phonton CLI, an open-source local-first AI coding agent.

The idea is simple: instead of treating an AI coding tool like a chat box, Phonton treats it like an engineering workflow.

It tries to follow this loop:

1. You give it a goal.
2. It creates a plan.
3. It works against your local repo context.
4. It verifies the generated diff.
5. You review the result before accepting it.

Most AI coding tools are optimized for speed and convenience. Phonton is more focused on making AI-generated changes easier to trust.

Why I built it

I wanted a CLI agent that was:

• local-first
• BYOK, so you use your own provider keys
• review-oriented
• built around verification
• able to remember repo decisions locally
• useful from the terminal

The goal is not to replace every tool like Claude Code, Codex, Cursor, or OpenCode. The goal is to explore a stricter workflow for AI-assisted coding: plan, verify, review, then ship.

Current status

Phonton is still early alpha.

It currently has:

• a Rust CLI/TUI
• provider adapters
• planning
• local memory
• repo indexing
• verification flow
• review commands
• checkpoint/rollback work

There are still rough edges, and I am not claiming it is production-ready yet.

Try it

npm install -g phonton-cli
phonton doctor
phonton plan "add input validation to config loading"

GitHub:

https://github.com/phonton-dev/phonton-cli

I would appreciate feedback from developers who already use AI coding agents and care about local-first workflows, reviewable diffs, and verification.