REDDIT · REDDIT// 37d agoTUTORIAL

Qwen3.5 users share OpenCode JSON fix

A LocalLLaMA user reports strong coding performance from Qwen3.5 122B/397B but recurring JSON write errors in OpenCode when tool output is emitted as an object instead of a string. Their practical fix is to enforce a system-prompt rule requiring JSON files to be written via a bash heredoc.

// ANALYSIS

This is a useful field fix for local-agent workflows, but it highlights brittle tool-call formatting boundaries rather than a true model capability gap.

–The workaround is prompt-level and easy to apply across test runs, so it is immediately useful for practitioners.
–The failure mode appears in structured file-writing paths, where minor output-shape drift can break automation pipelines.
–Using heredoc sidesteps strict JSON serialization expectations in tool interfaces and reduces format mismatch risk.
–Because this is community guidance from Reddit, teams should still validate against their own OpenCode/tooling stack and model quantization setup.

// TAGS

qwen3-5opencodellmai-codingcliprompt-engineering

DISCOVERED

37d ago

2026-03-05

PUBLISHED

37d ago

2026-03-05

RELEVANCE

7/ 10

AUTHOR

BitXorBit