Jeeves is a Qwen3.5-9B decision classifier that returns calibrated yes/no/rating calls together with the reasoning trace behind each verdict.
Yes, Jeeves is open source under the MIT license.
Jeeves is free to use.
Yes, Jeeves can be self-hosted (the source is available under the MIT license).
Jeeves is a reasoning-augmented decision classifier built on Qwen3.5-9B that produces calibrated yes/no and rating calls while exposing the reasoning behind each one. Open source: yes (MIT); self-hostable by downloading the weights and running local CUDA inference or using the Python SDK. It is free, has ~211 stars, and is maintained by PostHog — a well-known analytics company, which is a useful credibility signal for the project's provenance.
Jeeves takes a decision prompt and returns a structured verdict — yes/no or a rating — that the project describes as calibrated, and crucially it surfaces the reasoning trace that led to the verdict rather than emitting a bare label. That transparency is the differentiator: where a small classifier gives you an answer, Jeeves gives you an answer you can audit. It is built on Qwen3.5-9B, so it is a larger model than the sub-2B single-purpose decision models; you self-host it by downloading the weights and running CUDA inference or calling it through the Python SDK. Open source: yes (MIT); self-hostable; free.
Many GTM decisions are judgment calls that later need defending — is this lead a fit, does this reply signal intent, should this account be escalated. A bare classifier label is hard to trust or debug; Jeeves pairs the calibrated verdict with the reasoning behind it, so an operator can see why the model decided as it did and catch systematic errors before they compound across a pipeline. The honest read: "calibrated" is the vendor's own claim and should be checked against your labeled outcomes, and a 9B model is materially heavier to self-host than the tiny decision models — so choose Jeeves when the auditability of each call is worth the extra GPU footprint, and a smaller model when you only need a fast inline label.