J++
September 20, 2026 · View on GitHub
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Experimental language and Rust runtime for composing semantic Jev questions with exact methods as first-class values, plus a retained Python reference and offline Towow discovery demos that replay recorded Jev responses.
| At a glance | Details |
|---|---|
| Source | Source |
| Maintainer | Towow-ai. Independently curated; this entry is not an upstream submission or endorsement. |
| Format | Standalone .jpp sources via Rust jpp-cli; Python 3.12 reference package; browser demos with published response recordings. |
| Requirements | Rust toolchain for native build; Python for the reference tree. Fixture/replay runs need no live key. Live Jev adapters use TypeSafe System One when configured. |
| License | MIT. |
| Disclosure | AI-assisted catalog review; no affiliation with the maintainer. Listing is not an endorsement. Source and offline cargo test inspected. Live TypeSafe calls were not run. Discovery demos use recorded responses unless you enable live clients. |
When to use
Use it to study judgment-as-composition: questions and solving methods as reusable values, with offline fixtures proving the kernel without API spend. Prefer ordinary SDKs/CLIs when you only need a one-shot System One call rather than a language/runtime experiment.
How it works
The Rust kernel parses .jpp, checks language rules, and executes methods; fixtures supply observations so examples run without a model. The Python reference includes src/foundation/jv/client.py (JevClient) and Rust effects that can POST to https://api.typesafe.ai/v1/systemone when a key is present. Towow demos compare semantic-plus-lexical compositions against BM25 using published recordings.
Get started
git clone https://github.com/Towow-ai/jpp.git
cd jpp/rust
git checkout ec1720a4b93768502e176545dadda436ff1c5b32
cargo test --locked --workspace
cargo run -p jpp-cli -- run examples/composition.jpp
cargo run -p jpp-cli -- run examples/adaptive.jpp --fixtures examples/fixtures/adaptive.json
These fixture runs do not call a model API.
Examples and demos
- Native composition / adaptive / partial examples under
rust/examples/. - Hosted Towow lab pages (population, lab, real-relations) at the upstream GitHub Pages site; they execute published recordings in-browser.
- Language design docs under
docs/.
Limits and data handling
Experimental language; APIs and grammar may change. Live paths send judgment payloads to TypeSafe when enabled. Demo metrics and retrieval comparisons are author-documented offline experiments, not catalog-remeasured quality claims.
Review and maintenance
Reviewed on 2026-09-21 at commit ec1720a: MIT. AI-assisted source review of Rust CLI examples, JevClient, README, and LICENSE. cargo test --locked --workspace passed (all crates green; no failures). No live TypeSafe calls.