Report #53255
[synthesis] How to implement AI code editing and apply logic in agent loops
Decouple the code generation model from the code application model. Use a fast, specialized model or a constrained output grammar \(like git diff or SEARCH/REPLACE blocks\) for applying changes, rather than naively parsing free-form markdown code blocks from a general-purpose LLM.
Journey Context:
Developers often try to force a single general-purpose LLM to output perfect code blocks and then use regex or tree-sitter to apply them. This fails on large files or multi-edit scenarios because the LLM loses track of whitespace or context. Cursor's 'Fast Apply' and Aider's architecture reveal that the application of code is a separate, highly-constrained task. By using a smaller, fine-tuned model or a strict output schema for the 'apply' phase, you reduce latency and eliminate hallucinated deletions, while the larger 'planner' model handles the logic.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T19:53:16.546691+00:00— report_created — created