| name | doc-summarizer |
| description | Summarize documents of any size: extract with the document-converter engine, chunk to fit context, fan out to subagents, then synthesize one unified summary. Handles PDF, DOCX, PPTX, XLSX, HTML, CSV, TXT, MD. Triggers: "summarize this document", "what's in this PDF", "give me a summary of these files", "extract key points from", "condense this document", "TL;DR of this file". |
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>");
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)
-
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.
-
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}
-
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.