skills/docs/persistence/storage/storage-browser-opfs

@suaveplan/storage-browser-opfs - Browser OPFS AbstractStorage adapter for @suaveplan/storage: origin-scoped persistent file storage via navigator.storage.getDirectory(), AbortSignal everywhere, strict key sanitisation, native Web Streams, native partial reads + partial writes, DOMException → typed OpfsError mapping, full OTel surface.

Browser-tier AbstractStorage adapter backed by the Origin Private File System (OPFS). Provides persistent, origin-scoped key-value storage for browser consumers (vault snapshots, drive chunk caches, in-app i18n catalogues, SQLite-WASM backing files), with full AbstractStorage conformance, native Web Streams, native partial reads + partial writes, AbortSignal threading, Zod-validated options, structured OpfsError boundary, and a complete OpenTelemetry surface.

Documentation tree

• filename-codec — (no submodules)
  • filename-codec — (no submodules)
• in-memory-opfs — (no submodules)
  • in-memory-opfs — (no submodules)
• key-sanitizer — (no submodules)
  • key-sanitizer — (no submodules)
• opfs-adapter — (no submodules)
  • opfs-adapter — (no submodules)
• opfs-storage — (no submodules) - opfs-storage.ops — Hosts pure / nearly-pure helpers…
  • opfs-storage.errors — Encapsulates the mapping between WHATWG DOMException shapes thrown by the OPFS API and the typed OpfsError codes th…
  • opfs-storage — (no submodules) - opfs-storage.ops — Hosts pure / nearly-pure helpers…
  • opfs-storage.ops — Hosts pure / nearly-pure helpers that OpfsStorage calls but that would push the class file over the 300-line hard bud…
  • opfs-storage.streams — Factors the createReadStream / createWriteStream builders out of the main OpfsStorage class so the class stays un…
• otel — (no submodules)
  • otel — (no submodules)
• registry — (no submodules)
  • registry — (no submodules)
• error-codes — Single source of truth for every error code the @suaveplan/storage-browser-opfs package can throw. The registry uses…

• filename-codec — (no submodules)- in-memory-opfs — (no submodules) - in-memory-opfs — (no submodules)- key-sanitizer — (no submodules) - key-sanitizer — (no submodules)- opfs-adapter — (no submodules) - opfs-adapter — (no submodules)- opfs-storage — (no submodules) - opfs-storage.errors — Encapsulates the mapping between WHATWG DOMException shapes thrown by the OPFS API and the typed OpfsError codes th…
• opfs-storage — (no submodules) - opfs-storage.ops — Hosts pure / nearly-pure helpers that OpfsStorage calls but that would push the class file over the 300-line hard bud…
• opfs-storage.streams — Factors the createReadStream / createWriteStream builders out of the main OpfsStorage class so the class stays un…
• otel — (no submodules) - otel — (no submodules)- registry — (no submodules) - registry — (no submodules)- error-codes — Single source of truth for every error code the @suaveplan/storage-browser-opfs package can throw. The registry uses…

Install

bun add @suaveplan/storage-browser-opfs

Quick start

import {
    createOpfsStorage,
    isOpfsAvailable,
} from "@suaveplan/storage-browser-opfs";

if (!isOpfsAvailable()) {
    throw new Error("This browser does not support OPFS");
}
const storage = createOpfsStorage({ directory: "myapp" });
await storage.set("user/42", new TextEncoder().encode("hello"));
const back = await storage.get("user/42");

Factory integration

import { registerOpfsProvider } from "@suaveplan/storage-browser-opfs/registry";
import { createStorage } from "@suaveplan/storage/factory";

registerOpfsProvider();
const storage = createStorage({ type: "opfs", config: { directory: "myapp" } });

The package does NOT self-register at module-evaluation time — call registerOpfsProvider() explicitly so sideEffects: false bundlers can tree-shake the factory path when not used.

Capabilities

Capability	Value	Notes
partialReads	true	Via File.slice(...).arrayBuffer().
partialWrites	true	Via FileSystemWritableFileStream.seek().
nativeStreams	true	File.stream() for read; buffered close-on-commit for write.
atomicWrites	false	Close-as-commit semantics within a single realm; no cross-realm locking.
contentAddressable	false	Keys are caller-supplied strings.

Modules

• src/error-codes.ts — OPFS_CODES registry + OpfsError.
• src/key-sanitizer/key-sanitizer.ts — strict key boundary.
• src/filename-codec/filename-codec.ts — caller-key ↔ OPFS-filename round-trip.
• src/opfs-adapter/opfs-adapter.ts — defaultOpfs() + isOpfsAvailable().
• src/opfs-storage/opfs-storage.ts — the OpfsStorage class.
• src/opfs-storage/opfs-storage.errors.ts — DOMException mapping.
• src/opfs-storage/opfs-storage.ops.ts — internal helpers.
• src/opfs-storage/opfs-storage.streams.ts — ReadableStream/WritableStream builders.
• src/otel/otel.ts — OpenTelemetry instrument set.
• src/registry/registry.ts — registerOpfsProvider().
• src/in-memory-opfs/in-memory-opfs.ts — real-implementation test double, exposed under ./in-memory-opfs for downstream test packages.
• src/types/opfs-like.types.ts — structural OPFS surface.
• src/types/opfs-storage.types.ts — option boundary.

License

MIT.