Sweep 19 Sep 2026 · 02:36Z Build v2.1.278 500 read Stable v2.1.267 Latest v2.1.278 Next v2.1.278 Feeds RSS JSON llms.txt Unofficial
Claude Code v2.1.275 ·

File extension map extended: .cjs, .mts, .cts

File extension detection now recognizes .cjs, .mts, and .cts

TierYou'll noticehow much it should matter to you
Useful1my rating, 1 to 5
Signal1worth watching, 1 to 5
AreaElsewherewhat it touches
KindImprovementsin v2.1.275,
You'll notice

File extension detection now recognizes .cjs, .mts, and .cts

What

The map used to detect a file's language from its extension now includes .cjs (mapped to JavaScript) and .mts and .cts (both mapped to TypeScript), alongside the existing .jsx, .js, and .mjs entries.

Why

This lets Claude Code correctly recognize these CommonJS and TypeScript module file extensions wherever the language is used, such as syntax highlighting or file-type-aware behavior.

Read from
Names in the bundle.cjs.mts.cts
What the documentation says

See this entry in the whole of v2.1.275 →