TrustBand: Agents That Earn the Merge

TrustBand is a multi-agent software engineering workflow built on Band. It turns a bug report or issue into a verified pull request that a human can trust enough to merge. Instead of asking one coding agent to write a fix and self-evaluate it, TrustBand organizes seven specialized agents: Triage, Reproducer, Planner, Coder, Verifier, Security, Reviewer, plus a human approval gate. Each agent hands off structured Pydantic artifacts through a shared agent bus, and the live Band room shows the collaboration trail. The key idea is that trust must come from deterministic evidence, not model confidence. The Reproducer proves the bug first and can author a failing test when none exists. The Coder proposes a patch. The Verifier runs real tests, checks red-to-green behavior, catches regressions, and keeps a full smoke quality gate for release confidence. The Security agent blocks risky-but-passing fixes such as eval-based patches. The Reviewer summarizes the evidence and only then asks the human to approve or reject. TrustBand supports offline deterministic demos, real LLM runs, live Band room runs, JSON output for CI, benchmark scenarios, coverage gates, and a reproducible demo script. It demonstrates how Band can become the active collaboration layer for trustworthy agentic development, not just a chat transcript.