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pdf-inspector/napi/README.md
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Abimael Martell 98990cc550 feat(npm): add Linux musl and ARM64 N-API binaries (#233)
Adds x86_64-unknown-linux-musl, aarch64-unknown-linux-gnu, and
aarch64-unknown-linux-musl to the napi build targets so
@firecrawl/pdf-inspector works on Alpine and ARM64 Linux deployments.

- gnu arm64 cross-compiles with --use-napi-cross (old-glibc sysroot),
  musl targets with -x (zig + cargo-zigbuild), per the napi-rs template
- new platform packages carry npm libc metadata (glibc/musl)
- smoke-test job runs napi/test.mjs on all six targets before publish
  (Alpine containers for musl, ubuntu-24.04-arm runners for ARM64)
- bump to 1.12.0 to trigger publishing of all platform packages

Closes #216
2026-08-03 10:09:23 -07:00

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# PDF Inspector
Fast PDF classification and region-based text extraction for Node.js/Bun. Native Rust performance via [napi-rs](https://napi.rs).
Built by [Firecrawl](https://firecrawl.dev) for hybrid OCR pipelines — extract text from PDF structure where possible, fall back to OCR only when needed.
## Features
- **Smart classification** — text-based / scanned / image-based / mixed in ~1050ms, with a confidence score and per-page OCR routing.
- **Region-based extraction** — pull text from bounding boxes with per-region quality checks (`needsOcr`).
- **Layout-aware** — multi-column reading order, position and font info per text item, RTL support.
- **Robust text decoding** — CID/Type0 fonts via ToUnicode CMaps, plus automatic flagging of broken encodings so callers can fall back to OCR.
- **Lightweight** — native Rust core via napi-rs, no ML models, no external services; ~56 MB platform binary, TypeScript definitions included.
## Benchmark
[opendataloader-bench](https://github.com/opendataloader-project/opendataloader-bench) corpus (200 PDFs), local engines without model-based PDF parsing; OCR disabled. Scores 01, higher is better:
| Engine | Overall | Reading order | Tables (TEDS) | Headings | Speed |
|---|---|---|---|---|---|
| **pdf-inspector** | **0.875** | **0.915** | **0.814** | 0.788 | **0.470s** |
| liteparse | 0.873 | 0.913 | 0.693 | **0.811** | 0.750s |
| opendataloader | 0.831 | 0.902 | 0.489 | 0.739 | 2.569s |
| pymupdf4llm | 0.735 | 0.886 | 0.401 | 0.424 | 17.117s |
| markitdown | 0.589 | 0.844 | 0.273 | 0.000 | 16.165s |
Refreshed July 31, 2026, on Apple M4 Pro; speed is the median of five complete corpus runs after an excluded warm-up. Full methodology and versions are in the [repo README](https://github.com/firecrawl/pdf-inspector#benchmark), with raw timings and artifacts in the [results branch](https://github.com/firecrawl/opendataloader-bench/tree/abi/pdf-parser-benchmark-results).
## Install
```bash
npm install @firecrawl/pdf-inspector
# or
bun add @firecrawl/pdf-inspector
```
Prebuilt binaries for **Linux x64/ARM64** (glibc and musl/Alpine), **macOS ARM64**, and **Windows x64** — npm installs only the one matching your platform. No Rust toolchain needed.
## API
### `classifyPdf(buffer: Buffer): PdfClassification`
Classify a PDF as TextBased, Scanned, Mixed, or ImageBased (~10-50ms). Returns which pages need OCR.
```typescript
import { classifyPdf } from '@firecrawl/pdf-inspector'
import { readFileSync } from 'fs'
const pdf = readFileSync('document.pdf')
const result = classifyPdf(pdf)
console.log(result.pdfType) // "TextBased" | "Scanned" | "Mixed" | "ImageBased"
console.log(result.pageCount) // 42
console.log(result.pagesNeedingOcr) // [5, 12, 15] (0-indexed)
console.log(result.confidence) // 0.875
```
### `extractTextInRegions(buffer: Buffer, pageRegions: PageRegions[]): PageRegionTexts[]`
Extract text within bounding-box regions from a PDF. Designed for hybrid OCR pipelines where a layout model detects regions in rendered page images, and this function extracts text from the PDF structure for text-based pages — skipping GPU OCR.
Each region result includes a `needsOcr` flag that signals unreliable extraction (empty text, GID-encoded fonts, garbage text, encoding issues). When the cause is a suspected garbled text layer, `ocrReason` is set to `"suspected_garbled_text"`.
```typescript
import { extractTextInRegions } from '@firecrawl/pdf-inspector'
const result = extractTextInRegions(pdf, [
{
page: 0, // 0-indexed
regions: [
[0, 0, 300, 400], // [x1, y1, x2, y2] in PDF points, top-left origin
[300, 0, 612, 400],
]
}
])
for (const region of result[0].regions) {
if (region.needsOcr) {
// Unreliable text — send this region to OCR instead
} else {
console.log(region.text) // Extracted text in reading order
}
}
```
## Types
```typescript
interface PdfClassification {
pdfType: string // "TextBased" | "Scanned" | "Mixed" | "ImageBased"
pageCount: number
pagesNeedingOcr: number[] // 0-indexed page numbers
confidence: number // 0.0 - 1.0
}
interface PageRegions {
page: number // 0-indexed
regions: number[][] // [[x1, y1, x2, y2], ...] in PDF points, top-left origin
}
interface PageRegionTexts {
page: number
regions: RegionText[]
}
interface RegionText {
text: string
needsOcr: boolean // true when text is unreliable
ocrReason?: string // "suspected_garbled_text" when known
}
```
## Platforms
Prebuilt binaries ship as platform-specific packages installed automatically via `optionalDependencies`:
| Platform | Architecture | Package |
|----------|-------------|---------|
| Linux | x64 (glibc) | `@firecrawl/pdf-inspector-linux-x64-gnu` |
| Linux | x64 (musl/Alpine) | `@firecrawl/pdf-inspector-linux-x64-musl` |
| Linux | ARM64 (glibc) | `@firecrawl/pdf-inspector-linux-arm64-gnu` |
| Linux | ARM64 (musl/Alpine) | `@firecrawl/pdf-inspector-linux-arm64-musl` |
| macOS | ARM64 | `@firecrawl/pdf-inspector-darwin-arm64` |
| Windows | x64 | `@firecrawl/pdf-inspector-win32-x64-msvc` |
## License
MIT