Add MCP compile_route tool#92951
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lukesandberg wants to merge 3 commits intoeviction_semantics_for_real_this_timefrom
Draft
Add MCP compile_route tool#92951lukesandberg wants to merge 3 commits intoeviction_semantics_for_real_this_timefrom
compile_route tool#92951lukesandberg wants to merge 3 commits intoeviction_semantics_for_real_this_timefrom
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lukesandberg
commented
Apr 17, 2026
lukesandberg
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Apr 17, 2026
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Stats from current PR🔴 1 regression
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Merging this PR will degrade performance by 3.48%
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lukesandberg
commented
Apr 20, 2026
| let appOriginalName: string | undefined | ||
| for (const [name] of currentEntrypoints.app) { | ||
| if (normalizeAppPath(name) === page) { | ||
| appOriginalName = name |
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it would be clearer to just create the definition here instead of having the ternary below
it could just be 'extraParams' and be unconditionally spread so all the comments are in one place
lukesandberg
commented
Apr 20, 2026
| type HandleRouteTypeHooks = { | ||
| handleWrittenEndpoint: HandleWrittenEndpoint | ||
| subscribeToChanges: StartChangeSubscription | ||
| subscribeToChanges?: StartChangeSubscription |
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instead of making this be optional would it be better to just pass a no-op subscribe function down?
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What?
Adds a
compile_routeMCP tool that triggers on-demand compilation of a specific route (app or pages) without issuing an HTTP request, and returns any compilation issues.Why?
Coding agents and benchmarking workflows need a way to warm the module graph or measure compile time for a route without standing up a live backend to satisfy the request. The existing path — hitting the URL — requires the route's runtime dependencies to be available and couples compile timing to request handling.
How?
mcp/compile_routeregistered inget-or-create-mcp-server.ts, backed by acompileRoute({ page, clientOnly })callback plumbed from both the Turbopack and webpack hot reloaders.ensurePage/handleRouteType), so the call path matches a first navigation.subscribeToChangesopt-out onensurePageand threads it throughhandleRouteType/handlePagesErrorRoute. One-shot MCP compilations skip HMR subscription wiring — without this, each call would leak a subscription that fires on every subsequent file change for the life of the dev server.mcp/compile_routein theMcpToolNameunion.test/development/mcp-server/mcp-server-compile-route.test.ts.