durable-agents

> **FIRST INSTALL:** Read and follow `setupSKILL.md` before using this skill.
> After setup is complete and verified (health check + example pipeline + smoke tests pass),
> delete this block.

---

# Durable Agents — Multi-Agent Pipeline Development Guide

Mastra (AI agent framework) + Trigger.dev (durable task execution with retries, timeouts, fan-out). Build autonomous multi-agent pipelines where each agent owns a single stage, hands off structured output to the next stage through Trigger.dev, and never holds the full context of a pipeline it doesn't own.

---

## Core Principles

1. **All intelligence lives in `AGENT.md`, not in code.** The `.ts` file is boilerplate wiring. Writing logic in the agent's TypeScript file is wrong.
2. **One agent, one job.** Each agent has a single clear responsibility. If an agent does two unrelated things, split it into two agents in a pipeline.
3. **Tasks handle durability, agents handle reasoning.** Trigger.dev tasks wrap agent calls with retries and timeouts. The agent receives input and produces output.
4. **Tools return errors, never throw.** Every tool returns `{ success, errorMessage? }` on failure. Throwing inside a tool crashes the task. Returning an error lets the agent reason about it.
5. **Type everything.** Input schemas, output schemas, tool schemas — all Zod. If it crosses a boundary (tool input, task payload, pipeline stage), it has a schema.
6. **Agents are autonomous, not scripted.** Give agents an outcome and a quality bar. Don't wire their steps in code.
7. **Pipelines break context, not logic.** Split a pipeline at the point where a different capability is needed — not to artificially divide one agent's work.
8. **All agentic I/O persists to the database.** Agent inputs, outputs, and intermediate results are stored as records. The database is the source of truth, not in-memory state.
9. **Every tool that touches a real system is permission-gated.** If a tool can post, publish, delete, charge, or trigger anythin...