Fusion Coding: exploring how AI agents build and verify software.

I’m Abraham Xiong. I created Fusion Coding while building Govafy to explore how competing agents, structured evaluation, and human oversight can improve software quality and streamline pull request reviews. This is the engineering and learning behind the project.

Explore the architecture

What it is

Fusion Coding brings structure to AI-assisted software work.

It is an AI meta-harness that coordinates agents from different frontier labs. Agents using tools such as Codex and Claude Code work from a shared specification and a defined outcome, so their implementations can be evaluated against the same requirements.

The repository includes a verification harness and a tournament dashboard. The tournament workflow separates competing implementations, judging, integration, and final verification. Its purpose is to make the work and the evidence behind a decision inspectable.

A related area of development is Command Center, a local interface for working across coding-agent environments. That broader direction is still evolving.

Why I’m building it

While building Govafy, I learned that generating code did not settle questions about correctness, completeness, or maintainability. I needed a repeatable way to plan work, compare implementations, test behavior, and verify that the result met the requirements.

How should a task be defined, where should independent review enter the process, and what evidence should a person see before accepting a change?

A plausible implementation still needs to be checked. Fusion Coding gives me a structured way to explore those questions through working software and evidence I can inspect.

How tournaments work

One specification. Multiple approaches. A result to evaluate.

The process starts with clear scope, constraints, and acceptance criteria. Competing agents implement the same task separately, and evaluation examines their work against the requirements and available evidence.

A tournament can produce a single winner, no clear winner, or an integration of selected components from competing approaches. It may reveal that neither implementation meets the criteria.

Combining useful components creates another implementation to verify. Individual strengths do not establish that the pieces work correctly together. That is one of the most useful lessons from building the project.

How it’s built

The local runtime carries the workflow and its state. The web interfaces make that work accessible, while this public site explains the project. They serve different purposes within the same codebase.

Local runtime

TypeScript and Bun
Core local services, workflow execution, and automated tests.
SQLite
Local state for the verification harness, without a separate database server.
Git worktrees
Separate working copies for competing implementations and verification.
Provider adapters
Explicit interfaces to coding-agent runtimes. Command Center includes JSON-RPC transport.

Interfaces and browser checks

Next.js and React
The public website and the Command Center interface.
GSAP and Lenis
Animation and scrolling on the public website.
Playwright
Browser checks for the web interfaces.

My contribution

My contribution spans workflow architecture, specifications, implementation, debugging, and verification. I define the problem and acceptance criteria, examine competing approaches, and work through the technical decisions behind the result.

I use Linear to organize requirements and dependencies, and Claude Code, Codex, and Cursor throughout development. AI tools help produce and refine implementations. I remain responsible for reviewing their work and deciding what the evidence supports.

What I’m learning

Clear requirements make evaluation possible.

Building Fusion Coding has deepened my understanding of TypeScript, agent orchestration, evaluation workflows, Git branches and worktrees, testing, and software delivery. I’ve learned to separate a convincing answer from a working implementation and make acceptance criteria specific enough to guide development and review.

I’m learning to examine failures before choosing a repair, treat integration as work that needs its own verification, and present enough evidence for a person to make an informed decision. The interface should help explain the process without requiring someone to reconstruct every step.

Explore the workflow

Pull request review

I’m exploring how the same principles can support pull request reviews: connect a proposed change to its intended behavior, examine the implementation, and identify what the tests and evidence establish.

AI can assist that review while human judgment remains part of interpreting the result and deciding what should move forward.

From requirements to a demonstrable result

Fusion Coding develops skills relevant to forward-deployed engineering and customer-facing AI work: understanding a problem, defining measurable success, evaluating approaches, and explaining what works.

It gives me concrete examples for discussing how AI-assisted development can be structured and evaluated in an agency or enterprise setting.

This is an ongoing engineering project. I measure progress by whether I can explain the process, demonstrate the implementation, and verify it against the requirements.

About Abraham ↗