AI TOOLKIT
Get started
Recipes/API Servers

Hono

Example of using the AI TOOLKIT in a Hono server.

2 min readapi serversstreamingView source

You can use the AI TOOLKIT in a Hono server to generate and stream text and objects to the client.

Run it locally

$ npm install ai

Examples

The examples start a simple HTTP server that listens on port 8080. You can e.g. test it using curl:

curl -X POST http://localhost:8080

<Note>

The examples use the Vercel AI Gateway. Ensure that your AI Gateway API key is

set in the AI_GATEWAY_API_KEY environment variable.

</Note>

Full example: github.com/khulnasoft/ai-toolkit/examples/hono

### UI Message Stream

You can use the toUIMessageStreamResponse method to create a properly formatted streaming response.

import { serve } from '@hono/node-server';

import { streamText } from 'ai-toolkit';

import { Hono } from 'hono';

const app = new Hono();

app.post('/', async c => {

const result = streamText({

model: 'openai/gpt-4o',

prompt: 'Invent a new holiday and describe its traditions.',

});

return result.toUIMessageStreamResponse();

});

serve({ fetch: app.fetch, port: 8080 });

### Text Stream

You can use the toTextStreamResponse method to return a text stream response.

import { serve } from '@hono/node-server';

import { streamText } from 'ai-toolkit';

import { Hono } from 'hono';

const app = new Hono();

app.post('/text', async c => {

const result = streamText({

model: 'openai/gpt-4o',

prompt: 'Write a short poem about coding.',

});

return result.toTextStreamResponse();

});

serve({ fetch: app.fetch, port: 8080 });

### Sending Custom Data

You can use createUIMessageStream and createUIMessageStreamResponse to send custom data to the client.

import { serve } from '@hono/node-server';

import {

createUIMessageStream,

createUIMessageStreamResponse,

streamText,

} from 'ai-toolkit';

import { Hono } from 'hono';

const app = new Hono();

app.post('/stream-data', async c => {

// immediately start streaming the response

const stream = createUIMessageStream({

execute: ({ writer }) => {

writer.write({ type: 'start' });

writer.write({

type: 'data-custom',

data: {

custom: 'Hello, world!',

},

});

const result = streamText({

model: 'openai/gpt-4o',

prompt: 'Invent a new holiday and describe its traditions.',

});

writer.merge(

result.toUIMessageStream({

sendStart: false,

onError: error => {

// Error messages are masked by default for security reasons.

// If you want to expose the error message to the client, you can do so here:

return error instanceof Error ? error.message : String(error);

},

}),

);

},

});

return createUIMessageStreamResponse({ stream });

});

serve({ fetch: app.fetch, port: 8080 });

bash
  1. 1curl -X POST http://localhost:8080
index.ts
ts
  1. 1import { serve } from '@hono/node-server';
  2. 2import { streamText } from 'ai-toolkit';
  3. 3import { Hono } from 'hono';
  4. 4const app = new Hono();
  5. 5app.post('/', async c => {
  6. 6 const result = streamText({
  7. 7 model: 'openai/gpt-4o',
  8. 8 prompt: 'Invent a new holiday and describe its traditions.',
  9. 9 });
  10. 10 return result.toUIMessageStreamResponse();
  11. 11});
  12. 12serve({ fetch: app.fetch, port: 8080 });
index.ts
ts
  1. 1import { serve } from '@hono/node-server';
  2. 2import { streamText } from 'ai-toolkit';
  3. 3import { Hono } from 'hono';
  4. 4const app = new Hono();
  5. 5app.post('/text', async c => {
  6. 6 const result = streamText({
  7. 7 model: 'openai/gpt-4o',
  8. 8 prompt: 'Write a short poem about coding.',
  9. 9 });
  10. 10 return result.toTextStreamResponse();
  11. 11});
  12. 12serve({ fetch: app.fetch, port: 8080 });
index.ts
ts
  1. 1import { serve } from '@hono/node-server';
  2. 2import {
  3. 3 createUIMessageStream,
  4. 4 createUIMessageStreamResponse,
  5. 5 streamText,
  6. 6} from 'ai-toolkit';
  7. 7import { Hono } from 'hono';
  8. 8const app = new Hono();
  9. 9app.post('/stream-data', async c => {
  10. 10 // immediately start streaming the response
  11. 11 const stream = createUIMessageStream({
  12. 12 execute: ({ writer }) => {
  13. 13 writer.write({ type: 'start' });
  14. 14 writer.write({
  15. 15 type: 'data-custom',
  16. 16 data: {
  17. 17 custom: 'Hello, world!',
  18. 18 },
  19. 19 });
  20. 20 const result = streamText({
  21. 21 model: 'openai/gpt-4o',
  22. 22 prompt: 'Invent a new holiday and describe its traditions.',
  23. 23 });
  24. 24 writer.merge(
  25. 25 result.toUIMessageStream({
  26. 26 sendStart: false,
  27. 27 onError: error => {
  28. 28 // Error messages are masked by default for security reasons.
  29. 29 // If you want to expose the error message to the client, you can do so here:
  30. 30 return error instanceof Error ? error.message : String(error);
  31. 31 },
  32. 32 }),
  33. 33 );
  34. 34 },
  35. 35 });
  36. 36 return createUIMessageStreamResponse({ stream });
  37. 37});
  38. 38serve({ fetch: app.fetch, port: 8080 });

Troubleshooting

- Streaming not working when proxied

Browse all recipes