# salsa-rs/salsa

A generic framework for on-demand, incrementalized computation. Inspired by adapton, glimmer, and rustc's query system.

Repository: https://github.com/salsa-rs/salsa
Canonical: https://ross.abutalabs.com/products/salsa
Homepage: https://salsa-rs.netlify.app/
Language: Rust
License: Apache-2.0
License Family: permissive
Last push: 2026-08-21T10:31:29+00:00

## Health v2 (maintenance only)
Score: 98/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 98, release rhythm 96, longevity 100
- inputs: {"age_days": 2896, "days_push": 12, "days_rel": 30, "gap_med": 0, "n_releases_24m": 60}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2948, forks 221 (observed 2026-08-28T04:07:31.836555+00:00)

## What it is
Salsa is a Rust framework for on-demand, incrementalized computation, where programs are defined as memoized queries over inputs. It intelligently reuses cached results when inputs change, based on techniques from rustc's query system.

## Use cases
- build an incremental compiler in Rust
- memoize expensive computations that depend on changing inputs
- recompute only what changed when inputs are updated
- implement a query-based analysis pipeline
- build IDE-like tooling with fast reactive updates
- cache derived values in a reactive dataflow graph

## When to choose
- you are writing a compiler, linter, or language tooling in Rust that must respond to edits incrementally
- you need fine-grained memoization with automatic invalidation of derived values
- you want a proven design derived from rustc's query system

## When to avoid
- your computation is a one-shot batch job with no changing inputs
- you need incremental computation outside Rust
- you want a simple cache without dependency tracking overhead

## Facets
- artifact type: library
- maturity: active
- function: compiler, caching, concurrency, developer-tools
- domain: compilers, developer-tools, performance
- platform: rust, cross-platform
- tags: incremental-computation, memoization, query-system, reactive, rust-library

## Member repositories
- salsa-rs/salsa (main) score 98

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:31.836555+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T07:32:45.242887+00:00, confidence not recorded.
  - readme: https://github.com/salsa-rs/salsa (fetched 2026-08-28T04:07:31.836555+00:00, sha 50c7e890c43b)
  - homepage: https://salsa-rs.netlify.app/ (fetched 2026-08-29T09:47:58.422214+00:00, sha cc8a47d7ffa5)
  - registry_crates: https://crates.io/api/v1/crates/salsa (fetched 2026-08-29T09:47:58.425136+00:00, sha 21775ea7073c)
- Data as of 2026-08-30T08:39:29.467469+00:00.