12-Factor Agents for development workflows

It is mostly a guide, not a library you install and build your game on top of. There are some supporting packages and workshops in the repo, but the core value is the principles for building reliable agents.

The guide pushes against the "big prompt + tools + loop until done" approach.

I have been using AI coding workflows for multiple years already and that's the part where things usually break on big project. It might work for a demo or prototype. But in real Unity projects with long import times, slow build pipelines, and old god singletons no one wants to touch, suddenly LLM even with agents needs logs, state, approvals, retries, and boring deterministic scripts and tools instead of a magic AI button.

Few points I would steal for my game dev agents:

Own the prompts.
If an agent works on my project, I don't want the important prompt hidden inside a framework. I want it in the repo near requirements, diagrams, and maybe even next to scripts it can call. Same reason I like PlantUML: it can be reviewed, changed, reused.

Tools are just structured outputs.
"Run tests" should call a script. "Build WebGL" should call a script. "Check Addressables" should call a script. The LLM can choose what to try next, but it should not invent whether the build succeeded. Deterministic code should return the result.

Pause when action is risky.
An agent can prepare a PR, but I don't want it to push to master or upload a public build without explicit approval. Same for deleting assets, migrations, changing live configs, save compatibility, etc. It might sound obvious, but a lot of agent demos skip exactly this boring part.

Keep the state inspectable.
When an agent fails and retries, I want to see why. Unity has enough "works on my machine" mystery already. If the agent changed a prefab, fixed one error, then broke another platform, I need a history that can be inspected later.

Make agents small.
One agent for "prepare playable build" is okay. One for "investigate this crash report" is okay. A single agent that can modify code, assets, configs, CI, store metadata, and production data is a nice way to lose control. However I am wondering how many tokens can be wasted if there are too many small agents for each small step. Something I would like to test.

Of course, the repo is written mostly from SaaS/product experience, not Unity production. But I think the principles fit game dev really well, because our pipelines are slow, stateful, full of tools, and full of things that should not be changed by "vibes".

I am using my agent team at work daily and already modified it a few times based on the experience. Today I updated it according to 12-factor-agents principles, lets see if it yields better results or just turns into a bigger token drain with no significant benefits.

Have you already built any agent around your game project workflow? Not just coding in Cursor/Claude, but something that runs tests, checks logs, prepares builds, or validates assets, etc?

My unity agents:
https://github.com/AlexMerzlikin/unity-agent-team

12 factor agents:
https://github.com/humanlayer/12-factor-agents

#agent