mastra-hono

name	mastra-hono
description	Develop AI agents, tools, and workflows with Mastra v1 Beta and Hono servers. This skill should be used when creating Mastra agents, defining tools with Zod schemas, building workflows with step data flow, setting up Hono API servers with Mastra adapters, or implementing agent networks. Keywords: mastra, hono, agent, tool, workflow, AI, LLM, typescript, API, MCP.
license	MIT
compatibility	Node.js 22.13.0+ required for v1 Beta
metadata	{"author":"agent-skills","version":"1.0","type":"utility","mode":"assistive","domain":"development"}

Mastra + Hono Development

Build production-ready AI agents, tools, and workflows using Mastra v1 Beta with Hono API servers. This skill covers the complete stack from agent definition to deployment.

Target version: Mastra v1 Beta (stable release expected January 2026)

When to Use This Skill

Use when:

• Creating Mastra agents with tools and memory
• Defining tools with Zod input/output schemas
• Building workflows with multi-step data flow
• Setting up Hono API servers with Mastra adapters
• Implementing agent networks for multi-agent collaboration
• Authoring MCP servers to expose agents/tools
• Integrating RAG and conversation memory

Do NOT use when:

• Working with Mastra stable (0.24.x) - patterns differ significantly
• Building non-AI web APIs (use Hono directly)
• Simple LLM calls without agents/tools

Prerequisites

• Node.js 22.13.0+ (required for v1 Beta)
• Package manager: npm, pnpm, or bun
• API keys: OpenAI, Anthropic, or other supported providers

# Install v1 Beta packages
npm install @mastra/core@beta @mastra/hono@beta
npm install @ai-sdk/openai  # or other provider
npm install zod hono @hono/node-server

Quick Start

Minimal Agent + Tool + Hono Server

// src/mastra/tools/weather-tool.ts
import { createTool } from "@mastra/core/tools";
import { z } from "zod";

export const weatherTool = createTool({
  id: "get-weather",
  description: "Fetches current weather for a location",
  inputSchema: z.object({
    location: z.string().describe("City name, e.g., 'Seattle'"),
  }),
  outputSchema: z.object({
    temperature: z.number(),
    conditions: z.string(),
  }),
  // v1 Beta signature: (inputData, context)
  execute: async (inputData, context) => {
    const { location } = inputData;
    const { abortSignal } = context;

    if (abortSignal?.aborted) throw new Error("Aborted");

    // Fetch weather data...
    return { temperature: 72, conditions: "sunny" };
  },
});

// src/mastra/agents/weather-agent.ts
import { Agent } from "@mastra/core/agent";
import { openai } from "@ai-sdk/openai";
import { weatherTool } from "../tools/weather-tool.js";

export const weatherAgent = new Agent({
  name: "weather-agent",
  instructions: "You are a helpful weather assistant.",
  model: openai("gpt-4o-mini"),
  tools: { weatherTool },  // Object, not array
});

// src/mastra/index.ts
import { Mastra } from "@mastra/core/mastra";
import { weatherAgent } from "./agents/weather-agent.js";

export const mastra = new Mastra({
  agents: { weatherAgent },
});

// src/index.ts
import { serve } from "@hono/node-server";
import { Hono } from "hono";
import { MastraServer } from "@mastra/hono";
import { mastra } from "./mastra/index.js";

const app = new Hono();
const server = new MastraServer({ app, mastra });
await server.init();

app.get("/", (c) => c.text("Mastra + Hono Server"));

serve({ fetch: app.fetch, port: 3000 });
console.log("Server running at http://localhost:3000");
// Agent endpoint: POST /api/agents/weather-agent/generate

---

Core Patterns

Agent Definition

import { Agent } from "@mastra/core/agent";

const agent = new Agent({
  name: "my-agent",                           // Required: unique identifier
  instructions: "You are a helpful assistant.", // Required: system prompt
  model: openai("gpt-4o-mini"),               // Required: LLM model
  tools: { weatherTool, searchTool },         // Optional: object with named tools
});

// Model routing (1113+ models from 53 providers)
model: "openai/gpt-4o-mini"
model: "anthropic/claude-3-5-sonnet"
model: "google/gemini-2.5-flash"

// Model fallbacks for resilience
model: [
  { model: "anthropic/claude-3-opus", maxRetries: 3 },
  { model: "openai/gpt-4o", maxRetries: 2 },
  { model: "google/gemini-pro", maxRetries: 1 },
]

// Agent execution with memory
const response = await agent.generate("Remember my name is Alex", {
  memory: {
    thread: "conversation-123",   // Isolates conversation
    : ,         
  },
});

Tool Signatures (v1 Beta - CRITICAL)

// v1 Beta: execute(inputData, context)
execute: async (inputData, context) => {
  const { location } = inputData;  // First parameter: parsed input
  const { mastra, runtimeContext, abortSignal } = context;  // Second: context

  // Access nested agents via mastra
  const helper = mastra?.getAgent("helperAgent");

  // Always check abort signal for long operations
  if (abortSignal?.aborted) throw new Error("Aborted");

  return { temperature: 72, conditions: "sunny" };
}

// WRONG for v1 Beta:
execute: async ({ context }) => { ... }  // This is stable 0.24.x signature

Workflow Data Flow (CRITICAL)

This is where most errors occur. See references/workflow-data-flow.md for complete patterns.

import { createWorkflow, createStep } from "@mastra/core/workflows";

const step1 = createStep({
  id: "step-1",
  inputSchema: z.object({ message: z.string() }),
  outputSchema: z.object({ formatted: z.string() }),
  execute: async ({ inputData }) => {
    // inputData = workflow input (for first step)
    return { formatted: inputData.message.toUpperCase() };
  },
});

const step2 = createStep({
  id: "step-2",
  inputSchema: z.object({ formatted: z.string() }),  // MUST match step1 output
  outputSchema: z.object({ emphasized: z.string() }),
  execute: async ({ inputData }) => {
    // inputData = step1's return value directly
    return { emphasized: `${inputData.formatted}!!!` };
  },
});

const workflow = createWorkflow({
  id: "my-workflow",
  inputSchema: z.object({ : z.() }),     
  : z.({ : z.() }), 
})
  .(step1)
  .(step2)
  .();

Schema matching rules:

Rule	Description
Workflow input → Step 1 input	Must match exactly
Step N output → Step N+1 input	Must match exactly
Final step output → Workflow output	Must match exactly

Data access in steps:

execute: async ({
  inputData,      // Previous step's output (or workflow input for step 1)
  getStepResult,  // Access ANY step's output by ID
  getInitData,    // Get original workflow input
  mastra,         // Access agents, tools, storage
}) => {
  const step1Result = getStepResult("step-1");
  const originalInput = getInitData();
  return { result: inputData.formatted };
}

Hono Server Setup

import { MastraServer } from "@mastra/hono";

const app = new Hono();
const server = new MastraServer({ app, mastra });
await server.init();

// Endpoints auto-registered:
// POST /api/agents/{agent-name}/generate
// POST /api/agents/{agent-name}/stream
// POST /api/workflows/{workflow-id}/start

Custom route prefix:

const server = new MastraServer({
  app,
  mastra,
  prefix: "/v1/ai"  // Routes at /v1/ai/agents/...
});

Custom API routes:

import { registerApiRoute } from "@mastra/core/server";

registerApiRoute("/my-custom-route", {
  method: "POST",
  handler: async (c) => {
    const mastra = c.get("mastra");
    const agent = mastra.getAgent("my-agent");
    const result = await agent.generate("Hello");
    return c.json({ response: result.text });
  },
});

---

Common Mistakes Quick Reference

Topic	Wrong	Correct
Imports	import { Agent } from "@mastra/core"	import { Agent } from "@mastra/core/agent"
Tools array	tools: [tool1, tool2]	tools: { tool1, tool2 }
Memory context	{ threadId: "123" }	{ memory: { thread: "123", resource: "user" } }
Workflow data	context.steps.step1.output	inputData or getStepResult("step-1")
After parallel	inputData.result	inputData["step-id"].result
After branch	inputData.result	inputData["step-id"]?.result (optional)
Nested agents	import agent; agent.generate()	mastra.getAgent("name").generate()
State mutation	state.counter++	setState({ ...state, counter: state.counter + 1 })
v1 tool exec	execute: async ({ context })	execute: async (inputData, context)

---

Scripts Reference

Script	Purpose	Usage
scaffold-project.ts	Create new Mastra+Hono project	deno run --allow-all scripts/scaffold-project.ts --name my-project
scaffold-agent.ts	Create agent with tools	deno run --allow-all scripts/scaffold-agent.ts --name weather
scaffold-workflow.ts	Create workflow with steps	deno run --allow-all scripts/scaffold-workflow.ts --name process-data
scaffold-tool.ts	Create tool with schemas	deno run --allow-all scripts/scaffold-tool.ts --name fetch-weather
validate-workflow-schemas.ts	Validate step schema matching	deno run --allow-read scripts/validate-workflow-schemas.ts ./src/mastra/workflows/
check-version-patterns.ts	Detect v1/stable pattern mixing	deno run --allow-read scripts/check-version-patterns.ts ./src/mastra/

---

Additional Resources

Reference Files

• references/workflow-data-flow.md - Complete data flow patterns (CRITICAL)
• references/common-mistakes.md - Extended anti-patterns and fixes
• references/agent-patterns.md - Agent definition deep-dive
• references/tool-patterns.md - Tool signatures, wrappers
• references/hono-server-patterns.md - Server setup, routes, middleware
• references/testing-patterns.md - Vitest setup, mocking LLMs
• references/mcp-server-patterns.md - Model Context Protocol authoring
• references/agent-networks.md - Multi-agent collaboration, A2A
• references/rag-memory-patterns.md - Vector stores, embeddings, memory
• references/context-network-memory.md - Context networks for agent memory

Asset Templates

• assets/agent-template.ts - Agent boilerplate
• assets/tool-template.ts - Tool boilerplate (v1 signature)
• assets/workflow-template.ts - Workflow boilerplate
• assets/hono-server-template.ts - Hono+Mastra server setup
• assets/vitest-setup-template.ts - Test configuration

External Documentation

• Mastra v1 Beta Docs
• Hono Documentation
• Mastra GitHub

---

Limitations

• Targets v1 Beta only; stable (0.24.x) patterns differ significantly
• Scripts require Deno runtime with appropriate permissions
• MCP server patterns require MCP-compatible clients
• Agent networks require all participating agents to be registered in same Mastra instance

Related Skills

• research-workflow - Deep dive research for AI agent design
• web-search - Real-time information retrieval for agents