Using Mastra Processors with AI SDK

This example demonstrates how to use withMastra to wrap AI SDK models with Mastra processors and memory.

Setup

Install dependencies:
bash
```
pnpm install
```
Copy .env.example to .env and add your OpenAI API key:
bash
```
cp .env.example .env
```

Running the Examples

Basic Example (generateText with processors)

bash

pnpm start

This example shows:

Creating custom processors (logging, prefix)
Using withMastra to wrap a model
Running processors with generateText

Streaming Example

bash

pnpm start:stream

Tripwire/Abort Example

bash

pnpm start:tripwire

Memory Example

bash

pnpm start:memory

How It Works

The withMastra function wraps an AI SDK model with Mastra processors and memory:

typescript

import { openai } from '@ai-sdk/openai';
import { generateText } from 'ai';
import { withMastra } from '@mastra/ai-sdk';

// Create your processors
const myProcessor = {
  id: 'my-processor',
  async processInput({ messages }) {
    // Transform input messages
    return messages;
  },
  async processOutputResult({ messages }) {
    // Transform output messages
    return messages;
  },
};

// Wrap the model with processors
const model = withMastra(openai('gpt-4o'), {
  inputProcessors: [myProcessor],
  outputProcessors: [myProcessor],
});

// Use with generateText or streamText
const { text } = await generateText({
  model,
  prompt: 'Hello!',
});

Processor Lifecycle

processInput - Runs before the LLM call, transforms input messages
processOutputStream - Runs on each streaming chunk (streaming only)
processOutputResult - Runs after the LLM call, transforms output messages

Tripwire / Abort

Processors can abort processing by calling abort(reason):

typescript

const guardProcessor = {
  id: 'guard',
  async processInput({ messages, abort }) {
    for (const msg of messages) {
      if (containsBadContent(msg)) {
        abort('Content blocked by guard');
      }
    }
    return messages;
  },
};

When a processor aborts:

The model is NOT called
A blocked response is returned with the abort reason