Card #327 · OpenAI Platform & APIs
Structured JSON output errors in GPT-5 series models
Users are experiencing reliability issues with structured JSON outputs in GPT-5 models. Problems include the model concatenating the same JSON string twice or producing JSON that violates the defined schema order and contains unescaped quotes.
Pain score
0.15/ 1.00 · weighted product of four components
Reach0.32distinct authors (log-normalized)
Recency0.97freshness decay, half-life months
Engagement0.98upvotes + comments, normalized
Monetization0.50willingness-to-pay cues in evidence
§ Evidence — 3 verified quotes
the ‘content’ field, which is supposed to contain a JSON string, contains the same JSON string twice, separated by a newline character.
AI model is producing its output JSON in the wrong order, disobeying the schema, and only on Chat Completions, not Responses.
produces unescaped double-quotes, and breaks out of the JSON.
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