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Why JSON breaks LLM streaming

Strict JSON output looks clean on paper, but token-by-token delivery turns it fragile in production.

  • LLM
  • Streaming
  • Reliability

Core Failure Mode

JSON assumes completeness. Streaming is incomplete by definition.

When we parse too early, we fail. When we wait for completion, we lose responsiveness.

Better Pattern

Stream into a tolerant intermediate format, then transform into validated JSON chunks that can be safely applied.

Takeaway

For builder tools, perceived reliability beats strict formatting purity.