Bello

Bello

Build a cheaper, more reliable, better coding team from the models you already have. Codex, Claude Code, OpenAI, Anthropic, OpenRouter, in any mix. Bello puts a supervisor, a reviewer, an adversary, and a local log distiller around the coder, each optional, each on its own model. In our tests, one of the configurations used 66% less Codex usage at the same quality.

Contents

• TL;DR
• Install
• Quick start
• How Bello runs a task
• Results
• Configuration
• License

TL;DR

Bello runs a coding task through a coder and four optional parts: a runtime supervisor, a completion reviewer, an adversary, and a local log distiller. The coder, the supervisor, the reviewer, and the adversary each have their own model and reasoning effort, from a Codex or Claude Code subscription or from an API provider. The four components can be enabled or disabled independently.

In our tests, the Efficient Budget configuration used 66.3% less of the weekly Codex limit than Raw GPT-5.6 Sol XHigh without lowering average quality, and its mean score was 1.45% higher. Sol Ultra C+A raised the mean score over Raw Codex by 26.4%. The log distiller cut API-equivalent cost by 22% on Astra and by 14.8% on Luna.

Install

Python 3.11 or newer, git, and macOS, Linux with the bubblewrap package, or native 64-bit Windows 11 or Server 2022/2025 with the one-time sandbox preparation from docs/windows.md.

pipx install bello
bello doctor

Then add the model sources you want, any one is enough:

• Codex subscription: install the Codex CLI and run codex login.
• Claude Code subscription: pipx install 'bello[claude]' --force, then bello runtime login claude-code. The extra bundles the official Agent SDK and its CLI.
• API providers (OpenAI, Anthropic, OpenRouter, and other Pi providers): Node.js 22.19 or newer, bello runtime install once, then bello runtime login .
• Log distiller: pipx install 'bello[log-distiller]' --force. The model (599 MB) downloads on the first run with the distiller on. With subscription Codex it also downloads a compatible Codex helper on Apple Silicon, Windows x86_64, and Linux x86_64 (glibc 2.35+); see docs/native-codex-selection.md.

bello doctor shows what is ready, and bello update updates Bello. To run Bello from inside your coding agent, add the plugin, which includes the configuration advisor. For Codex:

codex plugin marketplace add AlexeyKulaev/Bello-codex-marketplace --ref main
codex plugin add bello@bello-marketplace

The same plugin has a Claude Code manifest in plugins/bello.

Quick start

After installing the plugin, open your coding agent in the project that contains task.md. The full start can be a short conversation:

You: Do you see the Bello plugin?

Agent: Yes. I can inspect the task, recommend a configuration, and run it with Bello.

You: Please recommend the best balance of price and quality for completing task.md.

Agent: I recommend Configuration X for task.md. It offers the best balance of price, quality, and time for this task.

You: Thanks. Please run task.md with Configuration X and keep me updated on what is happening.