Codex CLI on AWS Bedrock Can't Opt Into Prompt Caching, and One User's Logs Show 85% of a $1,386 Bill Was Cache Writes
GitHub / Hacker News·high signal
GitHub issue openai/codex#37674 documents that Codex CLI 0.147.0 running GPT-5.6-Sol on Amazon Bedrock cannot pass 'prompt_cache_options' or 'prompt_cache_breakpoint', so every request performs a cache write instead of a cache read. The reporter's August 5-8 production logs show 3,656 requests generating 171.94M cache-write tokens, an estimated $1,182.09 of a $1,386.46 total, with local tests averaging roughly 88K wasted cache-write tokens per request. The thread hit 139 points and 54 comments and the issue is still open, assigned to celia-oai. Anyone running Codex through Bedrock should check their token telemetry before the next invoice.