Document Summarizer

Summarize documents of any size. Extraction goes through the document-converter engine facade (dc.convertToMarkdown) — the same Docker-quarantined engine the document-converter skill uses. There are NO host-side extractor scripts here; the facade is the only extraction surface. Chunking and synthesis are agent work.

Prerequisites

• The document-converter package built and runnable: Docker available, image built (cd packages/document-converter && npm run build:image). See the document-converter SKILL for the full facade contract.
• Nothing else. No pdftotext/pandoc/Python on the host — the engine owns all format handling inside Docker.

Step 1 — Extract to Markdown via the engine

Call the facade; never invoke Python, docling, or pdftotext directly.

import { createDocumentConverter } from "@blackbelt-technology/pi-dashboard-document-converter";
const dc = createDocumentConverter({ image: "pi-doc-engine:0.1.0", stagingDir: "/abs/staging" });

const { output } = await dc.convertToMarkdown("<file_path>");              // digital PDF/DOCX/…
// scanned PDF: pass OCR explicitly
await dc.convertToMarkdown("<file_path>", { ocr: { mode: "force", lang: ["english"] } });

The result is a provenance-stamped .md in stagingDir. Read that file to get the document text. On failure the call rejects with DocConverterError (.code, .stderr) — surface UNSUPPORTED_FORMAT, OCR_LANG_UNSUPPORTED, INGEST_FAILED, DOCKER_UNAVAILABLE rather than retrying blindly.

Step 2 — Decide direct vs. chunked

Measure the extracted Markdown:

• < ~8,000 words (~10k tokens): summarize directly in the current context (Step 3a).
• >= ~8,000 words: chunk and fan out (Step 3b).

Step 3a — Direct summarization (small documents)

Read the extracted .md and produce a summary using the output format below: title/subject, key points, entities, document type, language.

Step 3b — Chunked summarization (large documents)

1. Chunk. Split the extracted Markdown into context-friendly pieces (~3,000–4,000 tokens each). Prefer natural boundaries — headings, sections, page markers in the engine output — over blind character cuts. No script needed; split with judgment.

2. Fan out. For each chunk launch a subagent (Agent tool, subagent_type: "general-purpose"), up to ~3–4 concurrent:

   Summarize this text chunk (chunk {i}/{total} of document '{filename}').
   Extract: key points, entities (people/orgs/dates/amounts), topics, and any
   conclusions or action items. Output as structured markdown.
   
   Text:
   {chunk_text}
   

3. Merge. Collect chunk summaries, deduplicate entities and key points, and produce one unified summary in the output format. If the merged result is still > ~8,000 words, run one more summarization pass on it.

Batch summarization

For a directory or glob: extract each file via dc.convertToMarkdown (run a few in parallel), then apply the single-document workflow per file. Emit a table:

| # | File | Type | Language | Words | Key Topics | Summary |
|---|------|------|----------|-------|------------|---------|
| 1 | invoice.pdf | Invoice | EN | 450 | AcmeCorp, 2024Q4 | Quarterly invoice… |

Summary output format

## Summary: {document_name}

**Type**: {document_type}
**Language**: {language}
**Word Count**: {word_count}
**Date**: {detected_date or file_modified_date}

### Key Points
- Point 1
- Point 2

### Entities
- **People**: …
- **Organizations**: …
- **Dates**: …
- **Amounts**: …

### Brief Summary
{2-3 paragraph narrative summary}

Special cases

• Scanned PDF, no text: the engine returns little/empty text on mode: auto. Re-run with ocr: { mode: "force", lang: [...] } (canonical language names).
• Encrypted / unsupported / empty: surface the DocConverterError.code and .stderr; report metadata only.
• Mixed-language: report the primary language, note others present.