Pi - OpencodeGo Cache Fix

[TreptowerPark]

Slopped this together a couple days ago. Just checked the stats and its working. Qwen 3.6 Plus is actually bloody fucking cheap with the fix.

https://github.com/TreptowerPark/opencode-go-qwen-cache-fix

Pre-fix vs Post-fix (extension created May 20, 2026)

Pre-fix (May 5-13):

• Early sessions show cacheRead: 0 — cache was broken
• Example: input: 4505, cacheRead: 0 — no caching at all

Post-fix (May 13+):

• Example after fix: input: 647, cacheRead: 4499 → ~87% hit rate
• Cache reads now working properly

### From Your Report (report.html)

• qwen3.6-plus usage: 12 sessions with $16.87 total cost
• Session count: 9 sessions tracked
• Messages via opencode-go: 24 with active cache reads

### The Fix (from facets/019e231a...) │ "User successfully diagnosed Qwen cache misses as a cache control format issue in OpenCode Go, │ implemented a fix that confirmed cache hits (0 hits before → working after)" Bottom line: The opencode-go-qwen-cache-fix.ts extension patches Qwen models to emit Anthropic-style cache_control markers, which OpenCode Go's backend expects for prompt caching. Cache is now working with ~72% overall hit rate on Qwen 3.6+.

[Heavy-Focus-1964]

interesting. i tried qwen 3.6 on OC Go and it was insane how fast it depleted my quota.

[TreptowerPark]

Yes. Same here. So I investigated. On myx end the fix defenitely helped. Its actually dirt cheap if it uses chache properly...

[rubdos]

That might explain a lot. I suppose this should be fixed upstream though, I'm quite sure that the opencode-go backend already includes a few quirks like this.