metadata-schema

A guide for maintaining Apache Tika’s registry of metadata names—the labels Tika uses to describe information found in files.

In plain words
What is it for?
Use it when changing metadata properties, regenerating the registry, investigating schema-check failures, or checking naming conventions.
Why use it?
It helps keep the registry, source code, and build checks aligned when metadata names are added or renamed.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/apache/tika/metadata-schema
Any agent
npx skills add apache/tika --skill metadata-schema
Clone the repo
git clone --depth 1 https://github.com/apache/tika

Made for: Claude Code, Codex.

Per session 53 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,568 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00053 $0.01568
Opus 5 $0.00026 $0.00784
Sonnet 5 $0.00011 $0.00314
Haiku 4.5 $0.00005 $0.00157

Measured 2d ago against content hash b15ff9a4b7c2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

metadata-schema scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.skills/devs/metadata-schema/SKILL.md · 120 lines

How it starts

The opening of the file, as written. The whole thing — 120 lines — stays where its author put it; the contents beside it link to each section on GitHub.

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.jsonKeyPrefix 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)

tika-metadata-schema/regen.sh

This does the full sequence in one shot: -am install so newly added Property/KeyPrefix classes are on the scan classpath, regenerate all three registries via the forked-exec profile, print a before/after key-count check (catches an incomplete classpath scan), git diff --stat the registries, then run the gate tests. Flags: --skip-install (only safe if nothing outside tika-metadata-schema itself changed since the last install) and --skip-tests for a faster inner loop. Then review the diff and commit the Property change and the regenerated JSON together.

Read the full file on GitHub · 120 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 120 lines · 53 tokens per session scan A b15ff9a4b7c2

Subscribe to this mod's changes

metadata-schema is a skill published in the GitHub repository apache/tika (4,018 stars, last pushed 2d ago), licensed Apache-2.0. It adds 53 tokens to every session and 1,568 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

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