Bun 1.3 + Anthropic Rust Rewrite Deep Dive — Bun.SQL Unified DB Client, Bun.Image, HTTP/3 QUIC, and the 960K-Line Zig→Rust Six-Day Port Redefining the 2026 Full-Stack JavaScript Runtime Standard On May 14, 2026 , the Bun team — now part of Anthropic — merged a pull request that ported roughly 960,000 lines of Zig code to Rust . Work began on May 4. Coding took six days. The PR landed ten days later. The Rust side is 681,000 lines, passes 99.8% of the existing test suite on Linux x64 glibc , leaves about 13,000 unsafe blocks behind, and shrinks the binary by 3–8 MB . Four months earlier, on January 6, Bun 1.3 went GA — Bun.SQL unified PostgreSQL, MySQL, MariaDB, and SQLite behind a single API; the built-in Redis client posted 7.9× the throughput of ioredis ; isolated installs and dependency catalogs reshaped the monorepo model; and the Security Scanner API moved supply-chain blocks to install time.…