Skip to content

Prior art

AFI is not a new idea. It is a small refactoring of ideas that already work, adapted for the specifics of AI-agent context. This page credits and differentiates.

POSIX

Borrowed: paths (/foo/bar), file/directory/symlink distinction, stat metadata shape (mode, size, timestamps), permission model semantics.

Not borrowed: the actual POSIX API surface (~30 syscalls beyond the essentials). AFI is deliberately smaller.

9P (Plan 9)

Borrowed: the idea that everything is a file — including operations themselves (see the FUSE binding's /.afi/search synthetic file).

Not borrowed: 9P's message-oriented wire protocol. AFI is transport- agnostic; if you want a wire, ride HTTP or MCP.

FUSE

Borrowed: the operation set (getattr, readdir, read), the mental model that a filesystem is a set of callbacks against a namespace.

Not borrowed: the kernel-userspace round-trip model. Most AFI providers run entirely in userspace, and the FUSE binding is one of four — not the primary one.

WebDAV

Borrowed: the notion of a filesystem over HTTP with structured metadata and access control.

Not borrowed: WebDAV's XML-heavy protocol, PROPFIND/PROPPATCH semantics, and lock model. AFI is a JSON world.

MCP (Model Context Protocol)

Borrowed: the tool-calling model, the pattern of a small transport grammar with rich extensibility, the discipline of "small spec, generous extensions".

Not competing with: MCP is a transport/RPC framework; AFI is a data-shape spec. AFI's recommended transport binding is MCP itself.

CSI (Container Storage Interface)

Borrowed: the entire naming pattern (interface, not implementation), the conformance-testing culture, the vendor-neutrality strategy of "seek a neutral home once we have ≥2 implementations".

Not borrowed: CSI's gRPC-only transport, Kubernetes-specific concepts (volumes, mounts, node/controller split). AFI is not Kubernetes-shaped.

LSP (Language Server Protocol)

Borrowed: the discipline of a small operation set, capability negotiation via a startup handshake, and the "editor-agnostic, language- agnostic" positioning that let LSP outlive its Microsoft origins.

Not borrowed: LSP's JSON-RPC framing (AFI is transport-plural), or LSP's text-document-centric worldview.

RAG (Retrieval-Augmented Generation)

Not borrowed at all. RAG assumes the retrieval is invisible to the agent; AFI assumes the agent explicitly navigates. These are complementary, not competing — a RAG system's underlying corpus can be exposed as an AFI provider, letting the agent choose between opaque retrieval and explicit exploration.

What's genuinely new

Nothing about AFI is technically novel. The contribution is:

  1. A shared shape for the "virtual FS over data" pattern the ecosystem was going to converge on anyway
  2. Explicit conformance profiles so providers can honestly declare what they support
  3. A discovery manifest that decouples client capability from provider capability
  4. Vendor-neutral governance from day one so the spec doesn't calcify around any one company's needs