You can just use it through Claude Code, so you get to keep the system prompt and tooling you are used to.

3rd party models are a drop-in replacement with `ANTHROPIC_BASE_URL` in Claude Code, something people seem to miss right now. And contrary to what Anthropic might like to have you think, you don't need Opus 4.7 to run the harness to get similar performance.

https://api-docs.deepseek.com/quick_start/agent_integrations...