Per-model custom request headers for DeepSeek Harness: define named header profiles in Settings → Plugins → Plugin configuration, pick one per model in the provider's model catalog, and every call to that model carries those headers.
A DeepSeek Harness plugin: per-segment Session cost in the composer statistics strip, priced from the harness model catalog (41 providers, ~1495 models).
DeepSeek Harness plugin for gateway routes: declares the OpenCode Go and Command Code route protocol + endpoint (so the API address never has to be typed) and completes their model lists. The OpenCode Go half puts DeepSeek V4.1 first; the Command Code half syncs all 81 models from its public catalog. Also adds the x-opencode-session header.