Nitro Imessage Agent Template

nitro-imessage-agent

A **durable** iMessage AI agent built on:

• Nitro v3 — the API server
• Chat SDK + `chat-adapter-sendblue` — message routing over Sendblue
• Vercel AI SDK + AI Gateway — LLM replies, swap models with one constant
• Vercel Workflow — durable orchestration with retryable "use step" units
• evlog — structured wide-event logging with first-class AI SDK integration (token usage, tool calls, cost estimation)

A user texts your Sendblue number, Sendblue posts a webhook to this server, the Chat SDK dispatches the message, a workflow runs an agent step (LLM + tools), and the final reply is sent back through Sendblue. Each step is retryable on its own, so a transient LLM error or send hiccup never drops the inbound message.

   ┌─────────┐    ┌──────────────┐    ┌──────────────┐   ┌────────────┐
   │ user    │───▶│   Sendblue   │───▶│  POST /api/  │──▶│ Chat SDK   │
   │iMessage │    │  (cloud)     │    │webhooks/...  │   │ onMention  │
   └─────────┘    └──────────────┘    └──────────────┘   └─────┬──────┘
        ▲                                                       │
        │                                                       ▼
        │                                           ┌────────────────────────┐
        │                                           │ workflow start(...)    │
        │                                           └───────────┬────────────┘
        │                                                       ▼
        │                                           ┌────────────────────────┐
        │                                           │ generateReply(use step)│
        │                                           │  ├── LLM (AI Gateway)  │
        │                                           │  ├