{"version":"2.1.271","anchor":"ink-renderer-requires-new-bunantcellsegmenter-native-api","canonical_anchor":"ink-renderer-requires-new-bunantcellsegmenter-native-api","heading":"Ink renderer requires new Bun.ant.CellSegmenter native API","tier":"internal","area":"Terminal UI","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.271\/e\/ink-renderer-requires-new-bunantcellsegmenter-native-api","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.271","markdown":"### Ink renderer requires new Bun.ant.CellSegmenter native API\n\nTerminal text rendering now requires a native Bun.ant.CellSegmenter API\n\n**What**\n\nClaude Code's terminal UI renderer (Ink) now uses a new grapheme and cell segmentation engine to lay out text, replacing the previous JavaScript-based segmentation. Grapheme\/cell segmentation is the process of figuring out where one visible character ends and the next begins, and how many terminal columns it takes up, which matters for emoji, combining characters and wide characters. This new engine requires a native API called `Bun.ant.CellSegmenter` and will throw an error if that API is missing from the Bun runtime build in use.\n\n**Why**\n\nThis moves text-layout work to a faster native implementation, but it means Claude Code now depends on running under a version of the `bun-internal` runtime that includes `Bun.ant.CellSegmenter`; older builds without it will fail.\n\n- Area: Terminal UI\n- Tier: Under the hood\n- Useful: 2\/5\n- Signal: 3\/5"}