Custom providers previously never enabled prompt-cache control, so agent turns re-billed the full context every request even on cache-capable backends.
- Add `CustomProvider.anthropicPromptCaching` opt-in flag in @fusion/core types
- Set pi-ai `compat.cacheControlFormat="anthropic"` on opted-in models in both registration paths: custom-provider-registry `toProviderConfig` and pi.ts `createFnAgent`
- Expose the new toggle in the dashboard CustomProvidersSection UI (with supporting CSS) and thread it through the legacy API + custom-provider routes
- Update docs (dashboard-guide, settings-reference) to document the new setting
- Add engine test coverage for the caching flag across provider registration and pi-create-fn-agent paths
- Add changeset for the fix
Files changed:
.changeset/fn-7689-custom-provider-prompt-caching.md | 7 +
docs/dashboard-guide.md | 1 +
docs/settings-reference.md | 2 +-
packages/core/src/types.ts | 15 ++
packages/dashboard/app/api/legacy.ts | 12 ++
packages/dashboard/app/components/CustomProvidersSection.css | 24 +++
packages/dashboard/app/components/CustomProvidersSection.tsx | 58 +++++-
packages/dashboard/src/routes/register-custom-provider-routes.ts | 16 ++
packages/engine/src/__tests__/pi-create-fn-agent.test.ts | 71 +++++++
packages/engine/src/__tests__/provider-registration.test.ts | 204 ++++++++++++++++++++-
packages/engine/src/custom-provider-registry.ts | 71 +++++--
packages/engine/src/pi.ts | 27 ++-
12 files changed, 473 insertions(+), 35 deletions(-)
Fusion-Task-Id: FN-7689
Fusion-Task-Lineage: b4f88f32-50da-4651-a546-432a95a1ab1c
Co-authored-by: Fusion (runfusion.ai) <noreply@runfusion.ai>
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