The TypeSafe Playground
The TypeSafe Playground is the official console UI for pasting state, mixing Choice / Score / Noul, and seeing typed answers before you commit JSON to production. It is not hosted on jev.pro and it is not a substitute for the API reference.
This page is for builders who already heard of Jev / System One and want the fastest official try-it surface. jev.pro is an independent unofficial field guide — not affiliated with TypeSafe AI. We do not sell, issue, or proxy API keys. We will not ask for your console cookie. Confirm the quick start on docs.typesafe.ai. For how this guide relates to official docs, see accessing the unofficial Jev documentation guide.
Steps
- Open the Playground and log in at console.typesafe.ai. You need TypeSafe access first — how to get access. Keys still come from the dashboard after access, not from this site.
- Paste text as the state. TypeSafe’s quick start example is a failing Stripe integration. English is the primary training language; images are not accepted.
- Add a Noul such as “Does this message express urgency?”
- Mix Noul, Choice, and Score in one call — you do not need three runs. Official docs: questions run in parallel.
- Copy the request into
POST /v1/systemoneor an official SDK. See your first API call. Production auth isAuthorization: BearerorTYPESAFE_API_KEY— API keys. - Pin
jev-1.13.0(or the current versioned id) in code. Settling wording in the UI does not pin the model in your service.
Docs pages that embed examples often link “Try it in the Playground” via console.typesafe.ai/decode#share/.... That is TypeSafe’s share format, not something jev.pro hosts.
Pitfalls
- Treating playground latency as a published SLA. TypeSafe’s own speed notes were measured from West Coast laptops for their evals. Vendor claims of 250k tok/s and 1200 RPM can change and are not a Playground guarantee.
- Embedding a proxy playground on this site, or pasting a key into jev.pro. Never. Use the official console.
- Editing criteria only in the UI, then promoting production from memory. Lock JSON in git.
- Mixing a Gateway experiment into the same mental model. Vercel AI Gateway uses a Gateway credential or OIDC and the model id
typesafe-ai/jev— not a TypeSafe first-party alias. The Playground is the console UI, not that door. - Reading a Noul near 0.5 as an access error. That is a 200 with an uncertain answer. 401 is a bad or missing key — do not retry 401.
From UI experiment to a pinned request
The Playground is the fastest way to learn the shape. Production is HTTP or an official SDK. You do not need the Playground to call the API. You do need it (or a fixture file) to stop arguing about wording in chat.
Unused state you paste into the UI still counts as input if you later send the same novel to the API. TypeSafe’s public list price is a vendor claim of $0.042 per million input tokens, output free — confirm on the models page before you paste a CRM dump.
If a share link fails, you are still on TypeSafe’s console, not on jev.pro support.
See also
FAQ
Do I need the Playground to call the API?
No. It is the fastest way to learn the shape. Production is HTTP or an official SDK.
Can I paste a key into jev.pro to try it?
No. Never. Use the official console.
Does the Playground issue keys?
Keys come from the TypeSafe dashboard after you have access — not from this site.
What this page does not claim
This page does not claim jev.pro hosts a Playground, proxies console cookies, or issues keys. It does not treat UI latency as an SLA. It does not freeze vendor price or RPM.
Disclaimer
This is an independent unofficial site and is not affiliated with TypeSafe AI; official documentation is available at https://docs.typesafe.ai.