Strict output still needs a no-answer lane.

Video caption

Strict output still needs a no-answer lane.

A parser exception becomes a dangerous default.

Complete, refused, incomplete and transport failure.

The no-answer branch is part of the contract.

#EricFieldNotes

Full written post / accessibility read

A strict schema is valuable because accepted output can match its declared shape. It does not mean every request returns a complete business decision. Hosted APIs document refusal and incomplete-response cases that the caller must handle separately.

Picture an illustrative account-review queue. A timeout leaves a partial response. The caller catches the parse error and defaults the account to approved so the queue keeps moving. The schema was never the defect. The fallback branch converted uncertainty into permission.

Use a result type with four separate branches. Only the complete branch reaches semantic validation. Refusal, incompletion and transport errors retain the case for review or bounded retry. Test each branch by injecting a canned response and checking the target state remains unchanged.

Write the refusal and incomplete paths before promoting strict output. Do this because a schema can constrain a completed answer, while the code around it decides what happens when there is no completed answer.

#EricFieldNotes

Four-beat scene transcript

1. Strict output still needs a no-answer lane.

A strict schema is valuable because accepted output can match its declared shape. It does not mean every request returns a complete business decision. Hosted APIs document refusal and incomplete-response cases that the caller must handle separately.

Visual: Refusal and truncation are real response states.

2. The fragile caller reads half a result.

Picture an illustrative account-review queue. A timeout leaves a partial response. The caller catches the parse error and defaults the account to approved so the queue keeps moving. The schema was never the defect. The fallback branch converted uncertainty into permission.

Visual: A parser exception becomes a dangerous default.

3. Make every response state explicit.

Use a result type with four separate branches. Only the complete branch reaches semantic validation. Refusal, incompletion and transport errors retain the case for review or bounded retry. Test each branch by injecting a canned response and checking the target state remains unchanged.

Visual: Complete, refused, incomplete and transport failure.

4. Never let error handling grant authority.

Write the refusal and incomplete paths before promoting strict output. Do this because a schema can constrain a completed answer, while the code around it decides what happens when there is no completed answer.

Visual: The no-answer branch is part of the contract.

Research and claim limits

• OpenAI: Structured Outputs guide (S175)

The examples identified as illustrative or simulated are design probes, not reported incidents. Vendor specifications do not establish workload performance.