The codebase is full of personality — creative loading messages, a model migration chain revealing product evolution, custom output styles, and a Chrome browser integration for authenticated sites.
Spinner Verbs — 200+ Loading Messages
ClaudingBeboppin'BoondogglingCombobulatingDiscombobulatingFlibbertigibbetingGitifyingHyperspacingLollygaggingMoonwalkingNoodlingPhotosynthesizingQuantumizingRazzle-dazzlingShenaniganingSpelunkingTomfoolering...183 more
Format: "[Verb] for [duration]" — e.g. "Sautéed for 4.2s"
Internal Codenames
Codename
Meaning
Notes
TENGU
Project name
100+ GrowthBook gates prefixed tengu_
CHICAGO
Computer use MCP
macOS native screen control
KAIROS
Assistant mode
Also KAIROS_BRIEF, KAIROS_CHANNELS
FENNEC
Deprecated Opus alias
Migrated: fennec-latest → opus
CAPYBARA
Buddy species
Hex-encoded to evade string scanning
AMBER QUARTZ
Voice kill-switch
tengu_amber_quartz_disabled
CHOMP
Prompt suggestion
tengu_chomp_inflection
Model Evolution (via migrations)
Fennec → Opus
"Fennec" was a deprecated Opus alias. fennec-latest → opus, fennec-fast-latest → opus[1m] + fast mode.
Sonnet 4.5 → Sonnet 4.6
Model upgrade with settings auto-update.
Opus → Opus 1M
Context window expansion 200K → 1M tokens.
Pro → Opus default
Pro plan users switched from Sonnet to Opus as default.
REPL bridge → Remote Control
Architecture rename for clarity.
Chrome Integration
claude-in-chrome
Uses your real authenticated browser (OAuth, logged-in sites)
GIF recording, console debugging, tab management, DOM interaction
vs WebBrowser: WebBrowser = dev (local servers, JS eval); Chrome = user's real sessions
JS alerts blocked (hang the extension) — recommends console.log debugging
Custom Output Styles
Drop .md files in ~/.claude/output-styles/. Frontmatter: name, description, keep-coding-instructions. Project styles in .claude/output-styles/ override user styles. Built-in: default, Explanatory, Learning.