# rustev
An embeddable Rust engine for making, evaluating and recording decisions over
evolving, partially trusted information. A versioned decision definition is
compiled into a plan: exact computation in Rust, semantic questions answered by
interchangeable backends that disclose what they can return, explicit
abstention, bounded execution, and an evidence record for every decision.
Rustev produces proposals, never grants. It does not authorize, own knowledge,
or execute effects; those belong to the application and to neighbouring
components (Aicortex, Rahi, statecraft-cli), each optional. Rustev is usable
without any of them.
## Status
Implemented, under approved and complete specs:
- `rustev-contract` and `rustev-core` (`002`): versioned documents, bounded
parsing, canonical identities, value kinds, exact operators, the plan
compiler with typed refusals, staged evaluation and selection policy.
- `rustev-runtime` (`003`, amended by `013`): bounded admission and
concurrency, one end-to-end deadline on an injectable clock, cost budgets
reserved before dispatch, declared retries and fallback that are part of
the plan's identity, honest cancellation, remote state on attempts that end
without a stop, and run records delivered under a declared sink policy.
- `rustev-eval` (`004`, amended by `014` and `015`): offline reproduction of
retained decisions from bounded replay bundles, candidate comparison,
evaluation reports with task adapter rules bound into their identity,
per-case reporting of unusable bundles, regression gates and temperature
fits. Live re-execution is not implemented (spec `026`).
- `rustev-backend-rules` (`005`): a deterministic rules backend; authored,
identified rules programs, not a model.
- `rustev` (`crates/rustev-cli`, `006`): plan check, compile and show; run;
replay; eval; gate; calibrate fit and qualify.
- `integrations/rustev-remote-http` (`009`): the versioned remote adapter
protocol over HTTP, client and server, including adapter-scoped
shared-state batching that is off by default until qualified.
- `integrations/rustev-jev` (`012`): a remote decision backend over TypeSafe's
Jev through the Vercel AI Gateway. Its evidence is development evidence: the
Gateway reports the served model as unknown, and the production transport
(spec `022`) is approved but not implemented.
- Reference packages `rustev-pkg-support-routing` (`007`, amended by `016`)
and `rustev-pkg-lodging` (`008`); neither amends a core crate.
Runtime optimization (spec `017`) is in progress: increment 1 (runtime-planned
batching and a bounded memory cache with invalidation, opt-in per plan) is
implemented; increment 2 (concurrent duplicate suppression and persistent
caches) is not. There is no local model backend (spec `011` is approved,
not implemented), and no quality or calibration claim: datasets and reports
are synthetic or of
synthetic provenance, and real labeled data is admitted only under spec `023`
(R-04, R-37). Nothing is released; every
manifest is `0.1.0` with `publish = false` (spec `021` is approved, not
implemented).
Approved specs not yet implemented: `010` optional integrations and serving,
`019` dynamic questions, `020` remote protocol refinements, `021` packaging
and first release, `022` Jev production transport, `023` real labeled data
qualification, `026` live re-execution, `011` first local semantic backend.
Drafts: `024` second local semantic backend, `025` wire-witness replay input.
`017` is approved and in progress. Every other spec (`000` to `009`, `012` to
`016`, `018`) is approved and complete.
The current roadmap is tracking issue
[#76](https://github.com/statecrafting/rustev/issues/76); it describes planned
work, not current behavior. Remaining unscheduled and research items are in
[docs/backlog.md](docs/backlog.md).
- Design (proposed): [docs/design/001-decision-engine-architecture.md](docs/design/001-decision-engine-architecture.md)
- Decisions: [docs/decisions/00-founding-decisions.md](docs/decisions/00-founding-decisions.md)
- Specs: [`specs/`](specs/); `spec-spine registry list` shows each status.
## Release
No version is published. The intended first family version is `0.1.0`
(spec `021`, as amended by `031`): `rustev-contract`, `rustev-core`,
`rustev-runtime`, `rustev-eval`, `rustev-backend-rules`,
`rustev-remote-http`, `rustev-pkg-support-routing` and `rustev-cli` (whose
binary is `rustev`), source archives only, MSRV 1.88, edition 2024, no
Cargo features. `make release-candidate` produces candidate evidence for a
clean commit; it uploads, tags and signs nothing. A candidate is not a
release, and a release is publicly accessible only once a fresh
registry-only consumer has passed against it (spec `021`, 3.10).
## Governance
Governed by [spec-spine](https://github.com/statecrafting/spec-spine), pinned
in `spec-spine.toml`, and initialized with statecraft-cli.
```sh
make tools # install the pinned spec-spine into .bin
make gate # read-only corpus gate, including ownership coverage
make code # build, test, clippy, fmt, boundary check
make verify # run each approved spec's declared acceptance
```
Apache-2.0.