Crate nidus 

nidus

A small, pure-Rust embeddable vector store: brute-force cosine search over a single append-only directory, with typed metadata filters and many logical collections sharing one embedding space. No FFI, no C, no SQL.

See SPEC.md for the full design.

use nidus::{Nidus, Config, Record, SearchOpts, Scope};
use std::collections::BTreeMap;

let mut db = Nidus::open(Config::new("/tmp/store", 3))?;
db.create_collection("docs")?;
db.upsert("docs", &[Record { id: "a".into(), vector: vec![1.0, 0.0, 0.0], attrs: BTreeMap::new() }])?;
let hits = db.search("docs", &[1.0, 0.0, 0.0], &SearchOpts { top_k: 5, ..Default::default() })?;

Structs

Config

Everything needed to open a store. Construct with Config::new and adjust via the builder setters.

Filter

A conjunction (AND) of predicates. An empty filter matches everything.

Footprint

A cheap, allocation-free snapshot of a store’s RAM/disk footprint — the introspection hook a host uses to decide whether it can afford more data before hitting a memory ceiling. vector_bytes is the dominant, predictable cost; the in-RAM index (ids + attrs) is extra on top and not counted here.

Hit

One search result. Carries its source collection (ids are unique only within a collection) and the matched record’s attrs, but deliberately not its vector.

Nidus

An open vector store. Synchronous; wrap in Arc<RwLock<Nidus>> for concurrent searchers + one writer (SPEC.md §6.5).

Record

A document: a caller-supplied id, its embedding, and typed metadata.

SearchOpts

Query parameters for a search.

Enums

Fsync

How aggressively writes are flushed to disk.

OpenMode

Whether the store may be written.

Predicate

A single attribute predicate. Predicates are AND-combined inside a Filter.

Scope

Which collections a Nidus::search ranks over (SPEC.md §7). Scores are comparable across collections because the whole store shares one embedding space. Accepts impl Into<Scope>, so &str and &[&str] work directly.

Value

A typed metadata value attached to a Record.

Type Aliases

Result

Result<T, Error>