THIS IS A ACTUAL F*CKING GOLDMINE Anthropic just shared one of the best tricks for Claude Code The idea: run Sonnet, Haiku 5.5 and Opus 5.5 at once, each doing only what it's best at Better results and way fewer tokens: every task lands on the right model You just start Claude Code like this: CLAUDE_CODE_SUBAGENT_MODEL=haiku claude --model sonnet here's how it splits: → Sonnet 5.5 runs the main session, writes the code, and applies fixes → Haiku 5.5 swarms the repo in parallel: search, grep, docs, and test audits at 340 tok/s → Opus 5.5 stays on call as architect for the big decisions and signs off on diffs → you stop burning Opus context on routine tasks and stop flooding main session with raw logs Opus only steps in at three moments: → before a plan locks → when the same error hits twice → before calling it done (signing off on git diff) Sonnet builds, Haiku swarms, Opus reviews JEV engineering is the same move one layer down: the forks that need no thinker (which file, which tool, retry or stop) go to JEV in milliseconds, and the big models only see the ones that split the full tree > Sonnet 5.5 runs the main session and coordinates code implementation > search maps the repo on Haiku 5.5 (read-only, 340 tok/s) > grep finds call sites on Haiku 5.5 (0.05x cost, isolated context) > audit scans diffs in a temporary worktree (isolation: worktree) > Opus 5.5 on call as architect, reviews synthesized diff before sign-off > JEV routes micro-forks in milliseconds paste the tree and this prompt into Claude Code ↓ "Reconfigure my Claude Code setup around this tree: 1. Run the main session on Sonnet 5.5 with Opus 5.5 as architect 2. Create three custom Haiku 5.5 subagents in .claude/agents/: search (maps repo), grep (finds call sites), and audit (runs isolated diff checks in a worktree) 3. Set isolation: worktree on audit so modifications never touch my working branch 4. Add one rule to CLAUDE.md: delegate all repository searches and test runs to Haiku 5.5 subagents to keep main context under 10k tokens 5. Route fast deterministic forks (tool choice, path selection, retries) through JEV Show me every change as a diff first. No edits until I say go" ↳ code.claude.com/docs/en/sub-… save it, it'll come in handy