model-usage - Claude MCP Skill

# Model usage

## Overview

Get per-model usage cost from CodexBar's local cost logs. Supports "current model" (most recent daily entry) or "all models" summaries for Codex or Claude.

TODO: add Linux CLI support guidance once CodexBar CLI install path is documented for Linux.

## Quick start

1. Fetch cost JSON via CodexBar CLI or pass a JSON file.
2. Use the bundled script to summarize by model.

```bash
python {baseDir}/scripts/model_usage.py --provider codex --mode current
python {baseDir}/scripts/model_usage.py --provider codex --mode all
python {baseDir}/scripts/model_usage.py --provider claude --mode all --format json --pretty
```

## Current model logic

- Uses the most recent daily row with `modelBreakdowns`.
- Picks the model with the highest cost in that row.
- Falls back to the last entry in `modelsUsed` when breakdowns are missing.
- Override with `--model <name>` when you need a specific model.

## Inputs

- Default: runs `codexbar cost --format json --provider <codex|claude>`.
- File or stdin:

```bash
codexbar cost --provider codex --format json > /tmp/cost.json
python {baseDir}/scripts/model_usage.py --input /tmp/cost.json --mode all
cat /tmp/cost.json | python {baseDir}/scripts/model_usage.py --input - --mode current
```

## Output

- Text (default) or JSON (`--format json --pretty`).
- Values are cost-only per model; tokens are not split by model in CodexBar output.

## References

- Read `references/codexbar-cli.md` for CLI flags and cost JSON fields.