perf(detail): react.cache Copilot calls + skip client refire

[priosshrsth]

Ref: OUT-3701

Foundation for the detail-page perf work. Two low-risk changes that the deeper refactor in the stacked PR builds on.

Changes

• CopilotAPI — wrap getInternalUser + getWorkspace in react.cache. Per-request memoization deduplicates Copilot calls within a single RSC / route handler invocation. Falls back to no-op in non-request contexts (jobs, CLI).
• OneTaskDataFetcher — new useFallback prop that seeds SWR with the SSR-rendered task and disables revalidateOnMount. Default behavior unchanged; the detail page opts in via the stacked PR.

Measured impact

Validated dedup: 4 call sites of getInternalUser(self) collapse to 1 actual network fetch on a typical detail-page load.

Test plan

• Detail page loads for IU + client tokens
• Mutations to task (title, body, assignee, workflow state) still work
• Non-detail pages (home, configure) unaffected

Stacked PR

The actual page handler refactor lives in #1214 (against this branch).

🤖 Generated with Claude Code

[linear-code]

OUT-3701

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
tasks-app	Ready	Preview, Comment	May 12, 2026 7:11am

[vercel]

Deployment failed with the following error:

Deploying Serverless Functions to multiple regions is restricted to the Pro and Enterprise plans.

Learn More: https://vercel.link/multiple-function-regions

[greptile-apps]

Greptile Summary

This PR introduces two low-risk performance foundations for the detail-page work: react.cache wrapping of getInternalUser/getWorkspace for per-request memoization, and a useFallback prop on OneTaskDataFetcher that seeds SWR with the SSR task and suppresses the mount-time refetch.

• CopilotAPI.ts: Module-level cachedFetchInternalUser/cachedFetchWorkspace use react.cache to deduplicate Copilot calls within a single RSC render pass; customApiKey is promoted to a class field to make its value available to those functions, and getWorkspace/getInternalUser are rewired to the cached variants.
• OneTaskDataFetcher.tsx: A new useFallback optional prop passes fallbackData + revalidateOnMount: false to SWR, and a useEffect proactively overwrites any stale SWR cache entry on mount so that a fresh SSR render is not silently lost on client-side revisits.

Confidence Score: 5/5

Safe to merge — both changes are additive and opt-in, with no modification to existing call paths for non-fallback consumers.

The react.cache wrappers are purely additive: wrapWithRetry is still used for every other method, and the two rewired methods delegate to the same underlying _ functions via the same withRetry budget. The useFallback prop defaults to undefined/falsy, leaving the existing SWR behaviour fully intact for all current call sites. The proactive mutate in the effect correctly addresses the revisit-stale-cache edge case raised in the prior review thread.

No files require special attention.

Important Files Changed

Filename	Overview
src/utils/CopilotAPI.ts	Adds react.cache-wrapped module-level functions for getInternalUser/getWorkspace; promotes customApiKey to class field; minor cleanup (remove redundant await, for-of const). Logic is sound and changes are well-scoped.
src/app/_fetchers/OneTaskDataFetcher.tsx	Adds useFallback prop to opt into SSR-seeded SWR; useEffect mutate correctly addresses the stale-cache-on-revisit problem flagged in prior review. Default code path is unchanged.

Sequence Diagram

sequenceDiagram
    participant RSC as RSC (detail page)
    participant CA as CopilotAPI
    participant Cache as react.cache
    participant Copilot as Copilot Network

    RSC->>CA: getInternalUser("self") [call site 1]
    CA->>Cache: cachedFetchInternalUser(token, key, "self")
    Cache->>Copilot: _getInternalUser("self") + withRetry
    Copilot-->>Cache: InternalUsers
    Cache-->>CA: cached result
    CA-->>RSC: InternalUsers

    RSC->>CA: getInternalUser("self") [call site 2]
    CA->>Cache: cachedFetchInternalUser(token, key, "self")
    Cache-->>CA: memoized (no network call)
    CA-->>RSC: InternalUsers

    RSC->>CA: getWorkspace() [call site 1]
    CA->>Cache: cachedFetchWorkspace(token, key)
    Cache->>Copilot: _getWorkspace() + withRetry
    Copilot-->>Cache: WorkspaceResponse
    Cache-->>CA: cached result
    CA-->>RSC: WorkspaceResponse

    RSC->>CA: getWorkspace() [call site 2]
    CA->>Cache: cachedFetchWorkspace(token, key)
    Cache-->>CA: memoized (no network call)
    CA-->>RSC: WorkspaceResponse

Loading

_{Reviews (2): Last reviewed commit: "fix(detail): seed SWR cache with fresh i..." | Re-trigger Greptile}

[priosshrsth]

@greptileai review the PR again. regarding the cache memoizing the error. If it throws error even after 3 retries then we already have an issue. So That is expected.

[SandipBajracharya]

LGTM