Add a 07-metrics folder

C² ships with six folders. Most projects never need a seventh. But once you're a few months in and want to know whether your estimates are any good, or how throughput is trending, the data is sitting in your contextbase already — in the frontmatter of your briefs and PRDs. A 07-metrics/ folder is where you make it legible.

This is a worked example of the adaptive principle: extend the structure when the work calls for it.

When it's worth it

Add 07-metrics/ when you have a real question you'd act on:

• Are my estimates calibrated? You've been filling in estimated_hours / actual_hours on Prompt Briefs.
• Is throughput trending up? You want a monthly count of briefs shipped.
• Where does time actually go? You want it broken down by area.

If you don't have a question, don't add the folder. Metrics nobody reads are just noise with a directory.

The shape

docs/07-metrics/
├── velocity/          ← monthly throughput notes
└── estimation.md      ← calibration: estimated vs actual, by area

Wiring it in

Two small moves and it's part of the method:

1. Point the Router at it. Add a line to AGENTS.md linking 07-metrics/ so the agent reads it when you ask for a calibration check.
2. Make it a Learn-loop output. When you run the periodic consolidation, have the agent read the completed Prompt Briefs, total the estimate-vs-actual, and update estimation.md. The data already exists in frontmatter — you're just summarising it.

The point

Nothing about this is special to metrics. The same three steps — decide there's a real question, give it a folder, point the Router at it — extend C² in any direction. The method grew this way in the first place.

This is C² being adaptive, not fixed — see the docs structure you're extending, or read the method.