Glossary: Schema validation
Schema validation has two layers. TypeSafe returns 422 when model, state, or a question shape fails the published contract on POST /v1/systemone. Your criteria then close the answer set so the model cannot invent a key outside the map. Neither layer proves the winner is factually correct. SEO-GEO reminder: schema-safe ≠ correct.
This glossary entry is for builders who already heard of Jev / System One and need a citable definition before they treat HTTP 200 as “the invoice is complete.” jev.pro is an independent unofficial field guide — not affiliated with TypeSafe AI. Confirm request shapes on docs.typesafe.ai. We do not sell or issue API keys.
How it shows up
A valid Choice can still pick billing on a technical outage. Semantic “is this invoice complete?” is a Noul or Score you write — not a second official /v1/validate we will invent. Validate-as-a-pattern pages on this site are patterns, not hidden TypeSafe routes.
Choice: unordered, max 255, choice + probabilities + confidence. Score: 2–10 ordered levels, fractional score allowed. Noul: P(yes) 0–1, no confidence. State is text/JSON only. Question IDs are not used in inference. 401 is a key problem; 429/529 are capacity; none of those mean “schema passed but unsure.” Unsure is a 200 with flat confidence or a Noul near 0.5 — see abstention.
Structured outputs on an LLM still generate tokens under a grammar. Jev returns typed fields without asking the model to author JSON prose. Pin jev-1.13.0 for fitted thresholds; jev-latest can move. RLCD does not make a valid key true.
Contrast
Schema validation vs factual correctness. Closed keys prevent out-of-schema strings. They do not prove the department, score, or yes/no is right.
Schema validation vs guardrail. 422 is “illegal body.” A guardrail is a content policy on a legal body.
Schema validation vs decision contract. The contract includes your floors and action map. Schema validation is the type gate.
Schema validation vs LLM structured outputs. Grammar-constrained generation is still generation. Jev’s contract is typed slots, not authored JSON documents.
Common mistakes
- Reading 200 as “true.”
- Inventing
/v1/validateas official. - Mapping 422 to “the model is unsure.”
- Treating closed Choice keys as a fact database.
- Asking Jev to emit a JSON document that restates the schema.
See also
FAQ
Does 200 mean the body was valid and the answer is right?
200 means the request parsed. Judge the answer against labels.
Structured outputs vs Jev schema?
Structured outputs still generate tokens under a grammar. Jev returns typed fields without asking the model to author JSON prose.
What status is a bad criteria shape?
Typically 422. Confirm the error envelope in official docs. Do not treat it as abstention.
Can criteria prove an invoice exists?
No. That is a Noul or an upstream system of record.
Limits
This is a jev.pro working definition. 422 and published request shapes are TypeSafe API behavior. We do not invent search volume. Schema-safe answers are not automatically factually correct.
Disclaimer
This is an independent unofficial site and is not affiliated with TypeSafe AI; official documentation is available at https://docs.typesafe.ai. Never treat jev.pro as TypeSafe official documentation. We do not sell, issue, or proxy API keys.