---
description: Reference for the legacy env.AI.autorag() Workers binding used by earlier AI Search instances.
title: Workers binding (legacy)
image: https://developers.cloudflare.com/og-docs.png
---

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# Workers binding (legacy)

Last updated Aug 24, 2026|Copy as Markdown|[View as Markdown](https://docs-durable-objects-instance-replaced-errors.previews.developers.cloudflare.com/ai-search/api/migration/workers-binding-legacy/index.md)|[Agent setup](https://docs-durable-objects-instance-replaced-errors.previews.developers.cloudflare.com/agent-setup/)

The `env.AI.autorag()` binding is the legacy API for AI Search. It will continue to work, but new projects should use the new AI Search bindings instead. For a step-by-step upgrade guide, refer to [Workers binding migration](https://docs-durable-objects-instance-replaced-errors.previews.developers.cloudflare.com/ai-search/api/migration/workers-binding/).

### `aiSearch()`

This method searches for relevant results from your data source and generates a response using your default model and the retrieved context:

```js
const answer = await env.AI.autorag("my-autorag").aiSearch({
	query: "How do I train a llama to deliver coffee?",
	model: "@cf/meta/llama-3.3-70b-instruct-fp8-fast",
	rewrite_query: true,
	max_num_results: 2,
	ranking_options: {
		score_threshold: 0.3,
	},
	reranking: {
		enabled: true,
		model: "@cf/baai/bge-reranker-base",
	},
	stream: true,
});
```

#### Parameters

`query` `string`required

The input query.

---

`model` `string`optional

The text-generation model used to generate the response for the query. For a list of valid options, check the AI Search generation model settings. Defaults to the generation model selected in the AI Search settings.

---

`system_prompt` `string`optional

The system prompt for generating the answer.

---

`rewrite_query` `boolean`optional

Rewrites the original query into a search optimized query to improve retrieval accuracy. Defaults to `false`.

---

`max_num_results` `number`optional

The maximum number of results that can be returned from the Vectorize database. Defaults to `10`. Must be between `1` and `50`.

---

`ranking_options` `object`optional

Configurations for customizing result ranking. Defaults to `{}`.

* `score_threshold` `number`optional  
  * The minimum match score required for a result to be considered a match. Defaults to `0`. Must be between `0` and `1`.

`reranking` `object`optional

Configurations for customizing reranking. Defaults to `{}`.

* `enabled` `boolean`optional

  * Enables or disables reranking, which reorders retrieved results based on semantic relevance using a reranking model. Defaults to `false`.
* `model` `string`optional

  * The reranking model to use when reranking is enabled.

`stream` `boolean`optional

Returns a stream of results as they are available. Defaults to `false`.

`filters` `object`optional

Narrow down search results based on metadata, like folder and date, so only relevant content is retrieved. For more details, refer to [Metadata filtering](https://docs-durable-objects-instance-replaced-errors.previews.developers.cloudflare.com/ai-search/configuration/retrieval/filtering/).

#### Response

This is the response structure without `stream` enabled.

```json
{
	"object": "vector_store.search_results.page",
	"search_query": "How do I train a llama to deliver coffee?",
	"response": "To train a llama to deliver coffee:\n\n1. **Build trust** — Llamas appreciate patience (and decaf).\n2. **Know limits** — Max 3 cups per llama, per `llama-logistics.md`.\n3. **Use voice commands** — Start with \"Espresso Express!\"\n4.",
	"data": [
		{
			"file_id": "llama001",
			"filename": "llama/logistics/llama-logistics.md",
			"score": 0.45,
			"attributes": {
				"modified_date": 1735689600000,
				"folder": "llama/logistics/"
			},
			"content": [
				{
					"id": "llama001",
					"type": "text",
					"text": "Llamas can carry 3 drinks max."
				}
			]
		},
		{
			"file_id": "llama042",
			"filename": "llama/llama-commands.md",
			"score": 0.4,
			"attributes": {
				"modified_date": 1735689600000,
				"folder": "llama/"
			},
			"content": [
				{
					"id": "llama042",
					"type": "text",
					"text": "Start with basic commands like 'Espresso Express!' Llamas love alliteration."
				}
			]
		}
	],
	"has_more": false,
	"next_page": null
}
```

### `search()`

This method searches for results from your corpus and returns the relevant results:

```js
const answer = await env.AI.autorag("my-autorag").search({
	query: "How do I train a llama to deliver coffee?",
	rewrite_query: true,
	max_num_results: 2,
	ranking_options: {
		score_threshold: 0.3,
	},
	reranking: {
		enabled: true,
		model: "@cf/baai/bge-reranker-base",
	},
});
```

#### Parameters

`messages` `array`required

An array of message objects. Each message has:

* `content` `string` \- The search query content.
* `role` `string` \- The role: `user`, `system`, or `assistant`.

---

`ai_search_options` `object`optional

Per-request overrides for retrieval and model behavior. Supports the following nested options:

* `retrieval.filters` `object` \- Narrow down search results based on metadata. Refer to [Metadata filtering](https://docs-durable-objects-instance-replaced-errors.previews.developers.cloudflare.com/ai-search/configuration/retrieval/filtering/) for syntax and examples.
* `retrieval.max_num_results` `number` \- Maximum number of chunks to return. Defaults to `10`, maximum `50`.
* `retrieval.retrieval_type` `string` \- One of `vector`, `keyword`, or `hybrid`.
* `retrieval.match_threshold` `number` \- Minimum similarity score (0-1). Defaults to `0.4`.
* `cache.enabled` `boolean` \- Override the instance-level cache setting for this request.
* `reranking.enabled` `boolean` \- Override the instance-level reranking setting for this request.

---

For the full list of optional parameters, refer to the [Search API reference](https://docs-durable-objects-instance-replaced-errors.previews.developers.cloudflare.com/api/resources/ai%5Fsearch/subresources/instances/methods/search/).

#### Response

```json
{
	"object": "vector_store.search_results.page",
	"search_query": "How do I train a llama to deliver coffee?",
	"data": [
		{
			"file_id": "llama001",
			"filename": "llama/logistics/llama-logistics.md",
			"score": 0.45,
			"attributes": {
				"modified_date": 1735689600000,
				"folder": "llama/logistics/"
			},
			"content": [
				{
					"id": "llama001",
					"type": "text",
					"text": "Llamas can carry 3 drinks max."
				}
			]
		},
		{
			"file_id": "llama042",
			"filename": "llama/llama-commands.md",
			"score": 0.4,
			"attributes": {
				"modified_date": 1735689600000,
				"folder": "llama/"
			},
			"content": [
				{
					"id": "llama042",
					"type": "text",
					"text": "Start with basic commands like 'Espresso Express!' Llamas love alliteration."
				}
			]
		}
	],
	"has_more": false,
	"next_page": null
}
```

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