Node.js 26 Ships With Major Removals

Several APIs that previously still worked (with warnings) are now fully removed, and others now emit runtime deprecation warnings.

• http.Server.prototype.writeHeader() is fully removed
• The legacy _stream_wrap, _stream_readable, _stream_writable, _stream_duplex, _stream_transform, and _stream_passthrough modules are fully removed
• The DEP0182 crypto deprecation has reached end-of-life
• The --experimental-transform-types flag is removed
• module.register() now triggers a runtime deprecation warning (DEP0)
• DEP0203 and DEP0204 crypto deprecations are now runtime deprecations
• DEP0201 stream deprecation is promoted to a runtime deprecation
• Building Node.js now requires GCC 13.2 and drops support for Python 3.9 as build prerequisites

Update code and build environments before adopting Node.js 26.

• Replace any use of http.Server.prototype.writeHeader() with writeHead()
• Replace any imports of the legacy _stream_* internal modules with the public stream APIs
• Remove any remaining use of the crypto API covered by DEP0182
• Remove any use of the --experimental-transform-types flag
• Audit code using module.register() and plan a replacement, since it now warns at runtime
• Audit code relying on the crypto APIs behind DEP0203, DEP0204, and stream API behind DEP0201, since they now warn at runtime
• Ensure build systems use GCC 13.2+ and Python 3.10+ if compiling Node.js from source