# Lightweight Cache and Incremental Processing

`markitect-tool` includes a small file-backed cache manifest for the core CLI.
It records Markdown file fingerprints and parse summaries so workflows can
detect which inputs changed before rerunning expensive operations.

This is intentionally not the future SQLite/AST/query backend. That richer
backend is tracked in `MKTT-WP-0006` and `MKTT-WP-0007`.

## Commands

Fingerprint one file:

```bash
mkt cache fingerprint docs/example.md
```

Build or refresh a manifest:

```bash
mkt cache build docs/ --root .
```

The default manifest path is:

```text
.markitect/cache/manifest.json
```

Check status against the manifest:

```bash
mkt cache status docs/ --root .
```

Exit behavior:

- `0`: clean
- `1`: new, changed, or deleted Markdown files detected

## Manifest Contents

Each entry records:

- relative path
- SHA-256 content hash
- size
- modification time
- parser identity
- heading, section, and block counts

The content hash is the authoritative change signal. Modification time and size
are recorded for diagnostics and future fast-path checks.

## Design Boundary

This layer provides:

- repeatable fingerprints
- changed/new/deleted detection
- simple parse summaries
- a transparent JSON file that can be inspected or removed

It does not provide:

- AST persistence
- JSONPath querying over cached documents
- SQLite/FTS indexes
- vector search
- policy-aware retrieval
- distributed cache synchronization

Those belong to later backend workplans.