jevgo
Community Go client for the System One API with functional options, context cancellation and optional Langfuse tracing.
Overview
jevgo is a community Go client for TypeSafe's System One API and its Jev model. You send a state and typed questions and get typed answers and probabilities your code can act on directly. It covers the same API surface as the official Python and TypeScript SDKs with the same defaults, written in idiomatic Go: functional options, context cancellation, sentinel errors, log/slog, and no dependencies outside the standard library. Differences from official SDK behaviour are documented in a compatibility section.
The example builds a request with a Noul for urgency, a Choice for department and a Score for customer frustration, and branches on the typed results. Optional Langfuse instrumentation ships as a separate contrib module so tracing does not add dependencies to the core. It is MIT licensed and not affiliated with TypeSafe.
What the decision model decides
| Type | Question | Answers |
|---|---|---|
| Yes / no | Does this convey urgency? | — |
| Choice | Which team should handle this? | billing · technical · other |
| Score | How frustrated is the customer? | Calm · Frustrated · Very angry |
How it works
- Create a client with options or TYPESAFE_API_KEY
- Build a Request with typed questions
- Call SystemOne with a context
- Read typed answers; optionally trace with Langfuse
Strengths
- Standard library only in the core
- Idiomatic Go error handling and cancellation
- Optional Langfuse observability module
Caveats
- Community client, not official
- Requires a TypeSafe key
Getting started
go get github.com/fgn/jevgoAt a glance
- Type
- Library
- Status
- beta
- Language
- Go
- Runtime
- Library
- Has code
- yes
- License
- MIT
Use cases and integrations
How curated lists describe it
A community Go client with a standard-library core and optional Langfuse tracing.
logicrw/awesome-jev-projectsGo client for TypeSafe AI's System One API (Jev), with optional Langfuse instrumentation.
hellogumbo/awesome-jev
Frequently asked questions
Does it have dependencies?
The core uses only the standard library; Langfuse tracing is a separate module.
Is it official?
No, it is a community client.
Does it match the official SDKs?
It covers the same API surface and defaults, with documented intentional differences.
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