OnyxFor Claude Code, Codex, Antigravity and Kimi
Same model.
Better mind.
Onyx wraps the coding agent you already use in a harness that remembers what worked, checks every action and seals every step. Same model, same settings, head to head: it has beaten plain Claude Code 112 games to 40.
macOS, Windows and Linux. Uses your own agent subscriptions.
The product
Memory. Governance. Provenance.
An agent on its own keeps one growing session, forgets it when the session ends, and leaves no record you can check. Onyx is a desktop app that fixes all three.
Remembers what matters. Knows what it doesn't know.
- Checkpoints keep every new task lean: 18k tokens, not 479k.
- Topics carry across checkpoints, so a thread never loses the plot.
- Lessons start as hypotheses and get disputed when evidence disagrees. One lucky case never becomes truth.
Every action checked before it runs.
- Per-project access: its folder, ask first, or the full machine.
- A policy gate on every tool call, with refusals recorded too.
- Shield redacts sensitive output before the model sees it.
Every step sealed. Every line traceable.
- Each action is a sealed object of 8 hashed sections. Change one byte and it shows.
- All of it lands in a hash-linked chain you can verify.
- Ask any line of code which turn wrote it.
Benchmarks
Proven head to head. Next, everything else.
Same model and effort on both sides, scored by something neither side controls, every run published. Chess comes first: long games played from memory, rated move by move by Stockfish. Onyx has won 12 of the 13 series.
Onyx stays light. Claude Code fills up.
Tokens carried into each game of the latest series.
So cost per move stays flat.
List cost per move, game by game. Claude Code's rose fivefold as its session grew.
Chess arena
112 wins, 40 losses, 13 draws across 13 series.
Coding arena
Fixed coding tasks repeated over rounds, graded by hidden tests.
Every agent
The same arenas through Codex, to show the gains carry across models.
Every platform
Windows, Linux and the packaged app, alongside macOS.
Costs use one list-price table for both sides (Opus 5.5, 1-hour cache writes). In the latest series Onyx cost $2.43 a game to Claude Code's $4.03 on play; its checkpoints add $0.74, leaving it 21% cheaper all in, and 29% across the series' three Onyx arms. Onyx is cheaper per move once a session passes about 160k tokens. Still improving: output length and the checkpoint model.