reMarkable OCR Lambda

Convert reMarkable tablet notebooks to markdown via Claude Vision.

Prose Desktop                          This Lambda
┌────────────────────┐                ┌─────────────────────────┐
│  Sync Button       │                │  .rm ──► Parse          │
│       │            │   POST /ocr    │       ──► Render PNG    │
│       ▼            │ ─────────────► │       ──► Claude Vision │
│  rmapi-js          │                │       ──► Markdown      │
│  Download .rm      │ ◄───────────── │                         │
└────────────────────┘    JSON        └─────────────────────────┘

How It Works

1. Typed text — Extracted directly from .rm files (firmware v3.3+), no OCR needed
2. Handwriting — Rendered to PNG, then OCR'd via Claude Vision API
3. Mixed pages — Both methods combined, returned as unified markdown

API

POST /ocr

Headers

Header	Required	Description
x-api-key	Yes	Lambda authentication
x-anthropic-key	For handwriting	Your Anthropic API key (BYOK model)

Request

{
  "pages": [
    { "id": "page-uuid", "data": "<base64 .rm data>" }
  ]
}

Response

{
  "pages": [
    {
      "id": "page-uuid",
      "markdown": "# Meeting Notes\n\nDiscussed the Q1 roadmap...",
      "confidence": 0.92
    }
  ]
}

Errors

Code	Description
401	Invalid or missing x-api-key
MISSING_ANTHROPIC_KEY	Handwriting detected but no x-anthropic-key provided

Development

pip install -r src/requirements.txt   # Install deps
pytest                                 # Run tests
pytest tests/test_handler.py -v       # Single file
API_KEY=test-key ./scripts/test-local.sh path/to/page.rm

Deployment

# Infrastructure
cd terraform && terraform init && terraform apply

# Lambda code
./scripts/deploy.sh

Environment Variables

Variable	Description
API_KEY_SECRET_ARN	Secrets Manager ARN for Lambda auth key
API_KEY	Local override for testing

Security

Bring Your Own Key (BYOK) — Users provide their Anthropic API key per-request via x-anthropic-key. Keys pass through to Anthropic but are never stored or logged. Typed-text-only pages skip Claude Vision entirely.

Dependencies

Package	Purpose
rmscene	Parse .rm v6 files
Pillow	Render strokes to PNG
anthropic	Claude Vision API
boto3	AWS Secrets Manager

Related

• Prose — Writing app that consumes this API