extract

Extract

What this skill does

Extract structured JSON from a bounded HTML or plain-text source inside the skill package, validate the result against a declared JSON Schema, and emit a digest-bound provenance packet. The runner is deterministic: it reads local fixture bytes, extracts headings, useful paragraphs, and HTTP/API terms, checks the packet against packets/extraction.schema.json, and returns runx.structured_extraction.result.v1.

This is not a scraper or crawler. Network fetch belongs in a separate governed web-fetch step. This skill starts after the bytes are already available as an approved package fixture, so the runx receipt can bind the input digest, schema digest, and validated output digest without depending on a live website.

When to use this skill

Use this skill when an agent needs a reproducible extraction packet from messy reference material, docs snapshots, benchmark fixtures, or captured public web content. It is appropriate when the source bytes have already been fetched, approved for local use, and pinned inside the skill package.

Use it as the extraction stage in a larger chain: fetch or curate bytes first, run structured extraction second, then pass the validated packet to a downstream agent, reviewer, search index, or evidence bundle.

When not to use this skill

Do not use this skill to fetch URLs, bypass network policy, process private customer data, parse credentials, or summarize a source without a schema. Do not use it when the desired output is free-form prose; this runner exists to produce typed, schema-checked JSON.

If the source bytes are not already present, stop with needs_input and use a web-fetch or repository-read skill with its own authority grant and receipt. If the schema is missing or unknown, stop with needs_more_evidence instead of inventing a packet shape.

Procedure

1. Resolve input_path and schema_path relative to the skill package.
2. Reject any path that escapes the package root.
3. Read the source bytes and JSON Schema bytes.
4. Record SHA-256 digests for both inputs.
5. Extract a bounded set of headings, paragraphs, and HTTP/API terms.
6. Build runx.structured_extraction.result.v1.
7. Validate the packet against the schema and deterministic internal checks.
8. Return the packet only when validation passes; otherwise fail closed.