Storage

The vector store holds wdpkr’s embedded summaries and serves cosine-similarity search. It’s a trait (VectorStore) with two implementations; pick one with store.provider.

	Turbopuffer (default)	nidus
Where	Hosted service	Local directory on disk
Setup	API key	None
Best for	Shared/CI indexes, large repos	Local-only, offline, zero-dependency
store.provider	turbopuffer	nidus
Credential	TURBOPUFFER_API_KEY	—
Dependencies	—	Pure Rust, no FFI / no C toolchain

Both rank by cosine similarity and return identical search results — only where the vectors live differs.

Turbopuffer

The default. A hosted vector database — vectors and metadata live in Turbopuffer, keyed by a per-repo namespace. Good when the index is built in CI and queried from many machines.

export TURBOPUFFER_API_KEY=...
wdpkr config set store.provider turbopuffer
# optional: store the key in the config file instead of the env var
wdpkr config set store.turbopuffer.api_key "$TURBOPUFFER_API_KEY"

Setting	Env var	Default	Description
store.provider	WDPKR_STORE_PROVIDER	turbopuffer	Backend selector
store.turbopuffer.api_key	TURBOPUFFER_API_KEY	—	API key (prefer the env var)

Note

The nested store.turbopuffer.api_key is the supported key. The older flat store.turbopuffer_api_key is still read for backwards compatibility, but prefer the nested form.

nidus

A local, file-backed store — no external service and no API key. It’s built on nidus, a small pure-Rust embeddable vector store, so wdpkr compiles and links with no FFI and no C/C++ toolchain — which is what lets it be vendored into other products cleanly. The whole index is just a directory you can copy, back up, or delete. Good for local-only workflows and offline use.

wdpkr config set store.provider nidus
# optional: choose where the store directory lives
wdpkr config set store.nidus.path ~/.local/share/wdpkr/nidus

Setting	Env var	Default	Description
store.provider	WDPKR_STORE_PROVIDER	turbopuffer	Backend selector
store.nidus.path	WDPKR_NIDUS_PATH	$XDG_DATA_HOME/wdpkr/nidus	Store directory path

The default path resolves to ~/.local/share/wdpkr/nidus (honoring $XDG_DATA_HOME).

How it works. One nidus directory holds every namespace — each wdpkr namespace maps to a nidus collection. Search is exact brute-force cosine similarity; nidus returns the cosine score directly, so score matches the Turbopuffer adapter exactly and min_score behaves identically across backends.

Caution

A nidus store is tied to a single embedding dimension (fixed when the directory is created). Opening it with a different dimension is a hard error — if you switch embedding provider or model, re-run wdpkr index --full against a fresh path (or delete the existing directory first). Vectors from different models aren’t comparable anyway.

Switching backends

Re-index after changing the store — the new backend starts empty:

wdpkr config set store.provider nidus
wdpkr index --full

See Configuration for how these settings resolve, and Providers for the summarizer and embedder.