Most agents fail in production for reasons the model can't fix. In this workshop, we start from an agent that fails and lies about it, then harness it step by step until it does the job reliably, without a single change to the prompt.
Workshop outline:
1. The failing agent: why it breaks, and why it claims success anyway
2. The agent loop, built up from an empty loop
3. A tool registry and context management
4. Guardrails, context compression and retries that hold whichever model sits underneath
5. Deterministic verification, so the agent fails honestly instead of claiming success
6. Moving secrets and fragile steps, like login, out of the model and into the harness
7. A harness plan for the agents you're building
This workshop has been presented at React Summit US 2026, check out the latest edition of this React Conference.












