A read-only data proxy for Source Cooperative, built as a Cloudflare Worker in Rust. It translates Source Cooperative URL paths into requests against cloud storage backends (S3, Azure Blob Storage, GCS) using the multistore S3 gateway.

The proxy supports GET, HEAD, and S3-compatible LIST operations with anonymous access, and resolves storage backends dynamically via the Source Cooperative API.

• Rust with the wasm32-unknown-unknown target
• wrangler (Cloudflare Workers CLI)

rustup target add wasm32-unknown-unknown
cargo install worker-build@0.7.5
npm install -g wrangler@3

wrangler dev

The proxy will be available at http://localhost:8787.

Unit tests for routing and pagination run on native targets:

cargo test

Integration tests run against a live instance:

wrangler dev &
python -m pytest tests/test_integration.py

# Version info
curl http://localhost:8787/

# List products for an account
curl "http://localhost:8787/cholmes?list-type=2&delimiter=/"

# List files in a product
curl "http://localhost:8787/cholmes/admin-boundaries?list-type=2&prefix=&max-keys=10"

# Get object metadata
curl -I http://localhost:8787/cholmes/admin-boundaries/countries.parquet

# Download with range request
curl -r 0-1023 http://localhost:8787/cholmes/admin-boundaries/countries.parquet -o chunk.bin

The proxy rewrites Source Cooperative URL paths (/{account}/{product}/{key}) into multistore's virtual bucket model, resolving storage backends dynamically via the Source Cooperative API.

Client Request: GET /{account}/{product}/{key}
  │
  ├─ [routing]   Parse path, rewrite to bucket={account}--{product}, key={key}
  ├─ [registry]  Resolve backend via Source API (product metadata + data connections)
  ├─ [cache]     Cache API responses (products: 5min, data connections: 30min, listings: 1min)
  ├─ [multistore ProxyGateway]  Generate presigned URL for the resolved storage backend
  └─ Stream response back to client

Write operations (PUT, POST, DELETE, PATCH) return 405 Method Not Allowed.

Environment variables (set in wrangler.toml or via Cloudflare dashboard):

See docs/plans/ for architecture and design documents.