OpenCode doesn't set prompt_cache_key for Mistral models, missing the documented 10% cached-token discount.
$npx -y skills add onlyterp/prompt-cache-skills --skill opencode-mistral-cache-keyInstalls into the current project.
Run `npx skills use "https://github.com/onlyterp/prompt-cache-skills" --skill "onlyterp/prompt-cache-skills/opencode-mistral-cache-key"` and follow the generated skill instructions now. Read its complete output, redirecting it to a temporary file first if necessary. Resolve relative paths from the supporting-files directory it provides.
Use the skills in "https://github.com/onlyterp/prompt-cache-skills" that are relevant to the current task. Run `npx skills add "https://github.com/onlyterp/prompt-cache-skills"` and select the relevant skills, then follow their instructions.