next breaking changes
Every breaking API change we have recorded in next on npm: 142 breaking changes in 55 versions. Below are its newest 6 versions, removals and renames first, each with its source.
Newest change October 6, 2026
On this page
16.4.0
- Signature changed
NextConfig.partialPrefetching
Was partialPrefetching?: boolean | 'unstable_eager'; now partialPrefetching?: boolean. npmjs.com
16.4.0-canary.56
- Default changed
Builds now mangle export names by default with Turbopack. Code relying on export names at runtime may be affected. github.com
16.4.0-canary.55
- Behavior changed
An explicitly set generateBuildId is now always used for the build ID. Check custom build ID logic. github.com - Default changed
experimental.turbopackSharedRuntime
experimental.turbopackSharedRuntime is now on by default. Set it to false to keep the previous behavior. github.com
16.4.0-canary.54
- Removed
agentUpgrade
The agentUpgrade option no longer accepts true. Remove or change that setting in your config. github.com - Behavior changed
Next data paths are matched case-sensitively now. Requests that relied on case-insensitive matching may change. github.com
16.4.0-canary.38
- Behavior changed
Routes are matched strictly by default in this canary. Check routes that relied on looser matching. github.com
16.4.0-canary.26
- Behavior changed
Interception routes now require canonical route targets. Routes that previously worked with non-canonical paths may now fail and need to be updated. github.com - Behavior changed
App pages that do not match any route now produce an error. Users with unmatched app pages must add matching routes. github.com
Check your code
These are the changes. To see which of them reach your code, scan a public repository, or have your coding agent call check_code with your manifest or lockfile over MCP. The API reads every change in every version, not only the newest. On Team and up, a fix pull request opens for the changes that reach a connected repository. Nothing merges or deploys.
Put your code on continuous management.
Scan a public repository now, or give your agent one line.
See how out of date your code is.
Tell your agent what changed since it was trained.
claude mcp add --transport http since https://api.since.dev/mcp