API Reference

Core Idea

Field-by-field reference for the two NextAdapter lifecycle functions: modifyConfig and onBuildComplete.

Key Concepts

• async modifyConfig(config, context): called for any CLI command that loads next.config.js, to let the adapter mutate the config.
• async onBuildComplete(context): called once the build finishes, with detailed routing and output data.

Reference Tables

modifyConfig param	Meaning
config	Complete Next.js configuration object
context.phase	Current build phase
context.nextVersion	Next.js version in use
context.projectDir	Absolute path to project dir
Returns	Modified config object (may be async)

onBuildComplete param	Meaning
context.routing.beforeMiddleware	Routes executed before middleware (headers/redirects)
context.routing.beforeFiles	Rewrites checked before filesystem matching
context.routing.afterFiles	Rewrites checked after filesystem matching
context.routing.dynamicRoutes	Dynamic route matching table
context.routing.onMatch	Routes applied after a successful match (e.g. immutable cache headers)
context.routing.fallback	Final rewrite fallback routes
context.routing.shouldNormalizeNextData	Whether /_next/data/<buildId>/... URLs are normalized during matching
context.routing.rsc	Route metadata for RSC routing behavior
context.outputs	Build outputs organized by type (see Output Types)
context.projectDir	Absolute path to project dir
context.repoRoot	Absolute path to detected repository root
context.distDir	Absolute path to build output dir
context.config	Final config, with modifyConfig applied
context.nextVersion	Next.js version in use
context.buildId	Unique identifier for the current build

Key Takeaways

1. modifyConfig operates on the raw config before build; onBuildComplete operates on the finished artifact graph.
2. context.config inside onBuildComplete already reflects any changes modifyConfig made.
3. routing.rsc and routing.shouldNormalizeNextData are the fields most relevant to adapters that need to mimic Next.js's own RSC/data-URL matching.

Connects To

• ch272 creating-an-adapter: the interface these hooks belong to.
• ch280 routing-information: deeper reference on the routing phases listed here.