anomalyco
feat: allow custom system prompts in global, project or custom directories
Fixes #7101
This PR adds support for a priority overrule of the opencode bundled system prompts in global, project or custom directory (via Env Setting)
Why is it helpful? In a reddit post, someone started creating very compact system-prompts to free up capacity in the context window. This patch allows using tailored system prompts instead of the bundled prompts. I hope this will increase creative and productive evolution on the system prompts for opencode and make it even more awesome.
How does it works: opencode (currently) uses the following system prompt files:
Modelname -> Filename
anthropic / claude -> anthropic.txt
gpt-5 -> codex.txt
gpt-, o1, o3 -> beast.txt
gemini- -> gemini.txt
Fallback, if nothing matches -> qwen.txt
With this PR, opencode codes will load the matching system prompt file in following order (highest priority to lowest priority):
- Environment: $OPENCODE_PROMPTS_DIR (e.g. OPENCODE_PROMPTS_DIR=/home/coder/my-custom-prompts)
- In the project-directory (e.g. : /home/coder/source/awesome-project/.opencode/prompt/
.txt ) - Global system prompts at ~/.config/opencode/prompt/<name.txt>
- Opencode's bundled system prompts inside opencode deployment
Q&A: Why not use AGENTS.md?
- AGENTS.md will append to the bundled system prompt, not replace it. So it won't help building tailored system prompts for new or low-spec coding models.
Why are the prompts under the /prompt/ directory?
- It follows the same directory structure as opencode's code to prevent confusing standards
How to start with a custom system prompt?
- Start by using a copy of the original prompts from opencode (see: https://github.com/anomalyco/opencode/tree/dev/packages/opencode/src/session/prompt ) and put them into one of the mentioned directories. Look into https://github.com/anomalyco/opencode/blob/dev/packages/opencode/src/session/system.ts to check the current model-matching algorithm.
