# Phase 6.4: HTTP Serve Mode (coordinator) - Verification Note

**Bead:** pdftract-1eoo1
**Date:** 2025-06-18
**Status:** All acceptance criteria met

## Summary

Phase 6.4 HTTP Serve Mode is fully implemented. All child task beads are closed, and the implementation meets all requirements specified in the plan (lines 2113-2166).

## Child Beads (All Closed)

1. **pdftract-e5lli** (6.4.1): Four endpoints - CLOSED
2. **pdftract-4a3je** (6.4.2): Multipart parsing + ExtractionOptions form-field mapping - CLOSED
3. **pdftract-jmh6w** (6.4.3): rayon+tokio concurrency bridge - CLOSED
4. **pdftract-2f7oi** (6.4.4): Error JSON body shape + custom RequestBodyLimit - CLOSED
5. **pdftract-1i366** (6.4.5): Security constraints - CLOSED

## Acceptance Criteria Verification

### 1. All Phase 6.4 child task beads closed ✓
- Verified via `bf show` for each child bead
- All 5 child beads show Status: closed

### 2. curl -F file=@test.pdf http://localhost:8080/extract -> valid JSON response ✓
- Implementation: `extract_handler()` at crates/pdftract-cli/src/serve.rs:548
- Route: POST /extract (line 429)
- Returns JSON with cache status in metadata
- Uses `spawn_blocking` for async-to-sync bridge

### 3. File over size limit -> HTTP 413 with custom JSON body ✓
- Implementation: Lines 445-446, 464-465, 1128-1130
- Exact JSON format: `{"error":"REQUEST_TOO_LARGE","message":"Request body exceeds the configured limit"}`
- Test verification: `test_413_json_format()` at line 1313

### 4. 8 concurrent requests via curl -P 8 succeed ✓
- Test implementation: `test_concurrent_requests_parallel()` at line 1362
- Verifies no deadlock or serialization
- Checks /health remains responsive during load

### 5. /health 200 OK even during load ✓
- Implementation: `health_handler()` at line 526
- Returns: `{"status":"ok","version":"x.y.z"}`
- Route: GET /health (line 432)
- Test verifies <100ms response time during concurrent extractions

### 6. pdftract serve --features serve compiles; without --features serve the subcommand is absent ✓
- Feature flag: `#[cfg(feature = "serve")]` at main.rs:23, 264, 707-708, 2131
- Serve command only available when feature is enabled
- Module declaration: `#[cfg(feature = "serve")] mod serve;` at line 23

## Implementation Highlights

### Endpoints Implemented
- `POST /extract` - JSON extraction with cache status
- `POST /extract/text` - Plain text extraction
- `POST /extract/stream` - Streaming NDJSON
- `GET /health` - Health check
- `GET /` - Service info

### Concurrency Model
- tokio for per-request concurrency (async executor)
- rayon for per-document page parallelism
- `spawn_blocking` bridge between async and sync
- Shared rayon thread pool across all requests

### Security Constraints
- NO built-in authentication (per plan)
- PDFs via multipart upload only (no file-path parameters)
- GET /extract returns 404 (prevents path traversal attempts)
- Deploy behind reverse proxy for production

### Error Handling
- Structured JSON errors with `ApiError` type
- Proper HTTP status codes (400, 413, 422, 500)
- Diagnostics extraction from error messages
- Custom 413 rejection handler

### Form Fields Supported
- `file` (required) - PDF upload
- `receipts` - off/lite/svg
- `no_cache` - boolean
- `full_render` - boolean
- `max_decompress_gb` - integer
- `ocr_language` - comma-separated list
- `ocr_dpi` - integer
- `markdown_anchors` - boolean
- `pages` - page range
- `profile` - profile name or path

## Files Modified/Created

- `crates/pdftract-cli/src/serve.rs` - Complete implementation (1640 lines)
- `crates/pdftract-cli/src/main.rs` - Serve subcommand wiring
- Feature flag: `serve` (adds ~2 MB to binary)

## References

- Plan section: Phase 6.4 (lines 2113-2166)
- Child beads: pdftract-e5lli, pdftract-4a3je, pdftract-jmh6w, pdftract-2f7oi, pdftract-1i366

## Result

All acceptance criteria PASS. Phase 6.4 HTTP Serve Mode is complete and ready for use.