# Metadata Schema

Working with tika-metadata-schema, the build-gated registry of Tika metadata keys, ...

- Repository: https://github.com/apache/tika (4119 stars)
- Category: Testing
- License: Apache-2.0
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add apache/tika --skill metadata-schema -g -a claude-code -y`
Codex: `npx skills add apache/tika --skill metadata-schema -g -a codex -y`
Cursor: `npx skills add apache/tika --skill metadata-schema -g -a cursor -y`
Gemini CLI: `npx skills add apache/tika --skill metadata-schema -g -a gemini-cli -y`

## Description

Working with tika-metadata-schema, the build-gated registry of Tika metadata keys, regeneration after Property changes, gate tests, naming conventions, post-rename sweeps. Use when adding or renaming metadata keys or when the schema gate fails.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

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Local override: `$TIKA_SKILLS_LOCAL/metadata-schema/LOCAL.md` (default `~/.tika-skills`),
read after this file, wins on conflict.

# Metadata Key Registry & Schema Skill

Working with `tika-metadata-schema`, the committed, build-gated registry of Tika's metadata keys.
File structure and the CLOSED/OPEN/TEMPLATE/UNKNOWN classification are in that module's `README.md`;
this covers conventions, regeneration, and the traps.

## The three registries

Under `tika-metadata-schema/src/main/resources/org/apache/tika/metadata/`:

- `metadata-keys.json`, closed set: every `Property` constant + the synthesized `tk:digest:*` cross-product.
- `metadata-open-namespaces.json`, `KeyPrefix` prefixes for runtime-minted names (`html:`, `message:raw-header:`, `mdb-prop:`).
- `metadata-key-fields.json`, TIKA-4797 `{class, field, key}` table for field-identity migration.

Committed on purpose: they are the reviewable audit trail of the key space (a rename or a dropped key
shows up as a diff). Don't switch to build-time-only generation, that loses the review signal.

## Regenerate (after adding/changing a Property or KeyPrefix)

```bash
tika-metadata-schema/regen.sh
```

The rest: https://github.com/apache/tika/blob/HEAD/.skills/devs/metadata-schema/SKILL.md