Agents-Concerto: Orchestrating Claude Code for PRs

Developer moruno21 released agents-concerto, an orchestration layer for Claude Code that enforces a four-role agent pipeline to generate pull requests without auto-merge. The system uses a Given-When-Then format for acceptance criteria, worktree isolation, and a two-party authority rule to keep final human control over merges. The open-source code is available at github.com/moruno21/agents-concerto.

Agents-Concerto: Orchestrating Claude Code for PRs To fix this, I built agents-concerto. It isn't a standalone app, but an orchestration layer for Claude /en/tags/claude/ Code. Think of it as a conductor and a set of players; the conductor manages the flow but never touches an instrument, ensuring the final merge always stays in human hands. The system relies on a strict set of constraints to maintain quality: Two-party authority: No agent that writes code is allowed to approve or merge it. Worktree isolation: Every agent operates in its own git worktree to avoid messing up the local checkout. No auto-merge: The process stops exactly at "PR ready." Model by complexity: The model isn't tied to a role; it's picked based on the complexity tier of the task. The Logic of Acceptance Criteria The biggest shift in my AI workflow was treating acceptance criteria as test specs rather than human notes. Using a Given-When-Then format Given X , when Y , then Z , the system ensures that every requirement has an observable result. This criterion travels through the pipeline: it's defined during the shaping phase, converted into a test during implementation, and verified by the reviewer. Because the "then" must be observable, it prevents the AI from cheating by asserting on internal state. The Agent Pipeline I've divided the labor across four distinct roles: Orchestrator Opus : Handles decomposition and dispatching. It is strictly forbidden from writing application code. Classifier Sonnet : A read-only agent that assigns a complexity tier complex vs standard to determine which model handles the task. Implementer: This agent uses a "Tidy First" approach—it submits a structural refactor commit first, then a separate behavioral commit. It never mixes the two. Reviewer Opus : Limited to Read , Grep , Glob , and Bash . It has no Write or Edit permissions, meaning it can describe a fix but cannot apply it. By forcing "outside-in" testing—asserting only on outputs, UI, or API responses—we've eliminated the "green tests, zero confidence" problem. Example of the lightweight orchestration structure CLAUDE.md Instruction set agents/ Markdown definitions for the 4 roles scripts/ Bash wrappers for execution For those looking for a real-world LLM agent deployment, the full logic is available here: https://github.com/moruno21/agents-concerto Next AI Agents for Regulated Industries: My Workflow → /en/threads/3719/