Response healing
Repair almost-JSON answers (fences, trailing commas, truncation) without a second model call.
Models asked for JSON sometimes return almost-JSON: wrapped in a markdown fence, a trailing comma, or truncated mid-object by max_tokens. Add plugins: [{ "id": "response-healing" }] to a request that uses response_format and the gateway repairs those deterministically: fences stripped, trailing commas removed, truncated brackets and quotes closed. No second model call, no extra cost, no change to latency worth measuring.
Valid JSON is never touched, requests without response_format are never touched, and a broken answer that cannot be repaired deterministically is returned as-is rather than guessed at. healing_applied: true appears only when a repair happened, so you can count how often your model actually needed it. Non-streaming requests only.
{
"model": "google/gemini-3.6-flash",
"response_format": { "type": "json_object" },
"plugins": [{ "id": "response-healing" }],
"messages": [{ "role": "user", "content": "List 3 colours as JSON" }]
}
// response, only when a repair was actually made:
// "healing_applied": true