One API for every storage backend

Apache OpenDAL is a unified data access layer written in Rust. It provides a single Operator API for reading, writing, listing, and deleting across more than forty storage backends — including WebDAV (the protocol Solid Pods expose), local filesystem, S3-compatible stores, and in-memory backends for testing.

The value is backend portability. Application code uses one API. Switching from a local filesystem in development to a Solid Pod in production is a configuration change, not a code change. The abstraction does not leak Solid-specific concerns into application logic.

OpenDAL is feature-gated: only the backends you actually use are compiled in. This keeps the binary small and the attack surface minimal. It is a Top-Level Apache Software Foundation project — stable, audited, and governed by a foundation with a track record of long-term stewardship.

Blogmarks uses OpenDAL as the storage access layer between all Rust components and the Solid Pod. The MCP server reads assets through OpenDAL. The ingestion pipeline writes through it.

In tests, the in-memory backend eliminates network dependencies entirely — the same application code runs against a local in-memory store in CI and against a real WebDAV Pod in production. No mocking, no test doubles, no conditional logic.

OpenDAL is feature-gated to include only the backends Blogmarks needs: WebDAV for production Solid Pods, local filesystem for development, and memory for testing. The compiled binary includes only what it uses.