# OpenAI

## Install

To use OpenAI models or OpenAI-compatible APIs, you need to either install `pydantic-ai`, or install `pydantic-ai-slim` with the `openai` optional group:

```bash
pip/uv-add "pydantic-ai-slim[openai]"
```

## Configuration

To use OpenAI models with the OpenAI API, go to [platform.openai.com](https://platform.openai.com/) and follow your nose until you find the place to generate an API key.

## Environment variable

Once you have the API key, you can set it as an environment variable:

```bash
export OPENAI_API_KEY='your-api-key'
```

The bare `'openai:'` prefix resolves to [`OpenAIResponsesModel`][pydantic_ai.models.openai.OpenAIResponsesModel], which uses the modern [Responses API](https://platform.openai.com/docs/api-reference/responses).

```python
from pydantic_ai import Agent

agent = Agent('openai:gpt-5.6-sol')
...
```

To pin to the legacy [Chat Completions API](https://platform.openai.com/docs/api-reference/chat) instead, use the `'openai-chat:'` prefix, which resolves to [`OpenAIChatModel`][pydantic_ai.models.openai.OpenAIChatModel].

Or initialise the model directly with just the model name:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIResponsesModel

model = OpenAIResponsesModel('gpt-5.6-sol')
agent = Agent(model)
...
```

By default, the model uses the `OpenAIProvider` with the `base_url` set to `https://api.openai.com/v1`.

## Configure the provider

If you want to pass parameters in code to the provider, you can programmatically instantiate the
[OpenAIProvider][pydantic_ai.providers.openai.OpenAIProvider] and pass it to the model:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIResponsesModel
from pydantic_ai.providers.openai import OpenAIProvider

model = OpenAIResponsesModel('gpt-5.2', provider=OpenAIProvider(api_key='your-api-key'))
agent = Agent(model)
...
```

## Custom OpenAI Client

`OpenAIProvider` also accepts a custom `AsyncOpenAI` client via the `openai_client` parameter, so you can customise the `organization`, `project`, `base_url` etc. as defined in the [OpenAI API docs](https://platform.openai.com/docs/api-reference).

```python {title="custom_openai_client.py"}
from openai import AsyncOpenAI

from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIResponsesModel
from pydantic_ai.providers.openai import OpenAIProvider

client = AsyncOpenAI(max_retries=3)
model = OpenAIResponsesModel('gpt-5.2', provider=OpenAIProvider(openai_client=client))
agent = Agent(model)
...
```

You could also use the [`AsyncAzureOpenAI`](https://learn.microsoft.com/en-us/azure/ai-services/openai/how-to/switching-endpoints) client
to use the Azure OpenAI API. Note that the `AsyncAzureOpenAI` is a subclass of `AsyncOpenAI`.

```python
from openai import AsyncAzureOpenAI

from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.openai import OpenAIProvider

client = AsyncAzureOpenAI(
    azure_endpoint='...',
    api_version='2024-07-01-preview',
    api_key='your-api-key',
)

model = OpenAIChatModel(
    'gpt-5.2',
    provider=OpenAIProvider(openai_client=client),
)
agent = Agent(model)
...
```

## Model settings

You can customize model behavior using [`OpenAIResponsesModelSettings`][pydantic_ai.models.openai.OpenAIResponsesModelSettings]:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIResponsesModel, OpenAIResponsesModelSettings

model = OpenAIResponsesModel('gpt-5.2')
settings = OpenAIResponsesModelSettings(
    temperature=0.2,
    service_tier='flex',
)
agent = Agent(model, model_settings=settings)
...
```

### Service tier

OpenAI supports controlling the [service tier](https://platform.openai.com/docs/api-reference/responses/create#responses-create-service_tier) to trade off latency and cost.
You can use the unified [`service_tier`][pydantic_ai.settings.ModelSettings.service_tier] field or the provider-specific [`openai_service_tier`][pydantic_ai.models.openai.OpenAIResponsesModelSettings.openai_service_tier] field. Both accept `'auto'`, `'default'`, `'flex'`, and `'priority'`, passed through unchanged. `openai_service_tier` takes precedence over the unified field when both are set.

## Responses API features

The features below are specific to the Responses API and only available on [`OpenAIResponsesModel`][pydantic_ai.models.openai.OpenAIResponsesModel] (the default). For background on how the Responses API differs from Chat Completions, see the [OpenAI API docs](https://platform.openai.com/docs/guides/migrate-to-responses).

### Reasoning mode

Models that support it (currently the GPT-5.6 family) can use OpenAI's [`standard` and `pro` reasoning modes](https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode). `standard` is the default; `pro` performs more model work to improve reliability on difficult tasks, at the cost of higher latency and token usage. The mode is independent of the reasoning effort: any combination of mode and effort is valid, and the unified [`thinking`](../thinking.md) setting only ever influences the effort, so `pro` is used only when you set it explicitly.

Configure the mode with [`openai_reasoning_mode`][pydantic_ai.models.openai.OpenAIResponsesModelSettings.openai_reasoning_mode]; there is no separate `pro` model to select:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIResponsesModel, OpenAIResponsesModelSettings

model = OpenAIResponsesModel('gpt-5.6-sol')
settings = OpenAIResponsesModelSettings(openai_reasoning_mode='pro')
agent = Agent(model, model_settings=settings)
...
```

The setting is ignored on models that don't support reasoning mode, per [`OpenAIModelProfile.openai_responses_supports_reasoning_mode`][pydantic_ai.profiles.openai.OpenAIModelProfile.openai_responses_supports_reasoning_mode].

### Native tools

The Responses API has native tools that you can use instead of building your own:

- [Web search](https://platform.openai.com/docs/guides/tools-web-search): allow models to search the web for the latest information before generating a response.
- [Code interpreter](https://platform.openai.com/docs/guides/tools-code-interpreter): allow models to write and run Python code in a sandboxed environment before generating a response.
- [Image generation](https://platform.openai.com/docs/guides/tools-image-generation): allow models to generate images based on a text prompt.
- [File search](https://platform.openai.com/docs/guides/tools-file-search): allow models to search your files for relevant information before generating a response.
- [Computer use](https://platform.openai.com/docs/guides/tools-computer-use): allow models to use a computer to perform tasks on your behalf.

Web search, Code interpreter, Image generation, and File search are natively supported through the [Native tools](../native-tools.md) feature.

Computer use can be enabled by passing an [`openai.types.responses.ComputerToolParam`](https://github.com/openai/openai-python/blob/main/src/openai/types/responses/computer_tool_param.py) in the `openai_native_tools` setting on [`OpenAIResponsesModelSettings`][pydantic_ai.models.openai.OpenAIResponsesModelSettings]. It doesn't currently generate [`NativeToolCallPart`][pydantic_ai.messages.NativeToolCallPart] or [`NativeToolReturnPart`][pydantic_ai.messages.NativeToolReturnPart] parts in the message history, or streamed events; please submit an issue if you need native support for this native tool.

```python {title="computer_use_tool.py" test="skip"}
from openai.types.responses import ComputerToolParam

from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIResponsesModel, OpenAIResponsesModelSettings

model_settings = OpenAIResponsesModelSettings(
    openai_native_tools=[
        ComputerToolParam(
            type='computer_use',
        )
    ],
)
model = OpenAIResponsesModel('gpt-5.2')
agent = Agent(model=model, model_settings=model_settings)

result = agent.run_sync('Open a new browser tab')
print(result.output)
```

#### Referencing earlier responses

The Responses API supports referencing earlier model responses in a new request using a `previous_response_id` parameter, to ensure the full [conversation state](https://platform.openai.com/docs/guides/conversation-state?api-mode=responses#passing-context-from-the-previous-response) including [reasoning items](https://platform.openai.com/docs/guides/reasoning#keeping-reasoning-items-in-context) is kept in context without having to resend it. This is available through the [`openai_previous_response_id`][pydantic_ai.models.openai.OpenAIResponsesModelSettings.openai_previous_response_id] field in
[`OpenAIResponsesModelSettings`][pydantic_ai.models.openai.OpenAIResponsesModelSettings].

When the field is set to `'auto'`, Pydantic AI automatically selects the most recent `provider_response_id` from the message history and omits messages that came before it, letting the OpenAI API reconstruct them from server-side state. The same chaining is applied inside a run across tool-call continuations and retries, so OpenAI never sees duplicate copies of the same messages.

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIResponsesModel, OpenAIResponsesModelSettings

model = OpenAIResponsesModel('gpt-5.2')
agent = Agent(model=model)

result1 = agent.run_sync('Tell me a joke.')
print(result1.output)
#> Did you hear about the toothpaste scandal? They called it Colgate.

model_settings = OpenAIResponsesModelSettings(openai_previous_response_id='auto')
result2 = agent.run_sync(
    'Explain?',
    message_history=result1.new_messages(),
    model_settings=model_settings
)
print(result2.output)
#> This is an excellent joke invented by Samuel Colvin, it needs no explanation.
```

As an alternative to passing `message_history`, you can pass a concrete `provider_response_id` from an earlier run as the seed. Pydantic AI uses the seed for the first request in the new run, then automatically chains to the response returned for that request on any subsequent in-run calls — so the chain still extends correctly if the run includes tool-call continuations or retries.

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIResponsesModel, OpenAIResponsesModelSettings

model = OpenAIResponsesModel('gpt-5.2')
agent = Agent(model=model)

result = agent.run_sync('The secret is 1234')
model_settings = OpenAIResponsesModelSettings(
    openai_previous_response_id=result.all_messages()[-1].provider_response_id
)
result = agent.run_sync('What is the secret code?', model_settings=model_settings)
print(result.output)
#> 1234
```

!!! note
    Referencing a stored response requires the response to have actually been stored. OpenAI stores responses by default; if you've disabled storage via [`openai_store=False`][pydantic_ai.models.openai.OpenAIResponsesModelSettings.openai_store] or your organization has Zero Data Retention enabled, chaining is unavailable and the full message history must be sent on every request.

#### Using durable conversations

OpenAI's [Conversations API](https://platform.openai.com/docs/guides/conversation-state?api-mode=responses#using-the-conversations-api) works with the Responses API to persist conversation state in a durable conversation object. If you already have an OpenAI conversation ID, pass it with [`openai_conversation_id`][pydantic_ai.models.openai.OpenAIResponsesModelSettings.openai_conversation_id]:

```python {test="skip"}
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIResponsesModel, OpenAIResponsesModelSettings

model = OpenAIResponsesModel('gpt-5.2')
agent = Agent(model=model)

model_settings = OpenAIResponsesModelSettings(openai_conversation_id='conv_...')
result = agent.run_sync('What did we discuss last time?', model_settings=model_settings)
print(result.output)
```

When a response belongs to a conversation, Pydantic AI stores the returned ID in `ModelResponse.provider_details['conversation_id']`. Setting `openai_conversation_id='auto'` uses the most recent same-provider conversation ID from the message history and sends only the new input items after that response.

When message-level [`conversation_id`][pydantic_ai.messages.ModelResponse.conversation_id] values are available, `auto` only reuses an OpenAI conversation from the current Pydantic AI conversation; pass a concrete OpenAI conversation ID to reuse one explicitly:

```python {test="skip"}
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIResponsesModel, OpenAIResponsesModelSettings

model = OpenAIResponsesModel('gpt-5.2')
agent = Agent(model=model)

model_settings = OpenAIResponsesModelSettings(openai_conversation_id='conv_...')
result = agent.run_sync('What did we discuss last time?', model_settings=model_settings)

follow_up_settings = OpenAIResponsesModelSettings(openai_conversation_id='auto')
result2 = agent.run_sync(
    'Summarize the next step.',
    message_history=result.new_messages(),
    model_settings=follow_up_settings,
)
print(result2.output)
```

Pydantic AI does not create OpenAI conversations for you. Use the OpenAI client to create the conversation, then pass its ID to `openai_conversation_id`. The `conversation` and `previous_response_id` parameters are mutually exclusive in the OpenAI API, so `openai_conversation_id` cannot be combined with [`openai_previous_response_id`][pydantic_ai.models.openai.OpenAIResponsesModelSettings.openai_previous_response_id].

#### Message Compaction

The Responses API supports [compacting message history](https://developers.openai.com/api/docs/guides/compaction) to reduce token usage in long conversations. Compaction produces an encrypted summary that replaces older messages while preserving context.

The easiest way to enable compaction is with the [`OpenAICompaction`][pydantic_ai.models.openai.OpenAICompaction] capability:

```python {title="openai_compaction.py" test="skip"}
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAICompaction

agent = Agent(
    'openai-responses:gpt-5.2',
    capabilities=[OpenAICompaction()],
)
```

By default, `OpenAICompaction` runs in **stateful mode**: it configures OpenAI's server-side auto-compaction via the `context_management` field on the regular `/responses` request, and OpenAI triggers compaction whenever the input token count crosses a threshold it manages for you. This mode is compatible with [`openai_previous_response_id='auto'`](#referencing-earlier-responses) and [`openai_conversation_id`](#using-durable-conversations).

To override the threshold, pass [`token_threshold`][pydantic_ai.models.openai.OpenAICompaction]:

```python {title="openai_compaction_token_threshold.py" test="skip"}
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAICompaction

agent = Agent(
    'openai-responses:gpt-5.2',
    capabilities=[OpenAICompaction(token_threshold=100_000)],
)
```

As an alternative, `OpenAICompaction` supports a **stateless mode** (`stateless=True`) that calls the stateless `/responses/compact` endpoint via a `before_model_request` hook. Use this in [ZDR](https://openai.com/enterprise-privacy/) environments where OpenAI must not retain conversation data, when using [`openai_store=False`][pydantic_ai.models.openai.OpenAIResponsesModelSettings.openai_store], or when you need explicit out-of-band control over when compaction runs. Stateless mode requires you to specify either a [`message_count_threshold`][pydantic_ai.models.openai.OpenAICompaction] or a custom `trigger` callable:

```python {title="openai_compaction_stateless.py" test="skip"}
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAICompaction

agent = Agent(
    'openai-responses:gpt-5.2',
    capabilities=[OpenAICompaction(message_count_threshold=20)],
)
```

The mode is inferred from which parameters you pass: supplying `message_count_threshold` or `trigger` implies stateless mode, otherwise stateful mode is used. You can also pass `stateless=True` or `stateless=False` explicitly. Mixing parameters from different modes raises [`UserError`][pydantic_ai.exceptions.UserError].

!!! tip
    Stateful compaction pairs especially well with [`openai_previous_response_id='auto'`](#referencing-earlier-responses) or [`openai_conversation_id`](#using-durable-conversations). Both rely on OpenAI's server-side conversation state, so OpenAI can use a previously compacted context as the starting point for the next turn without you having to resend it.

For lower-level use cases, you can call [`compact_messages`][pydantic_ai.models.openai.OpenAIResponsesModel.compact_messages] directly on the model.

## Chat Completions API

If you need the [Chat Completions API](https://platform.openai.com/docs/api-reference/chat) instead of the default [Responses API](https://platform.openai.com/docs/api-reference/responses), pin to it with the `'openai-chat:'` prefix or [`OpenAIChatModel`][pydantic_ai.models.openai.OpenAIChatModel]:

```python
from pydantic_ai import Agent

agent = Agent('openai-chat:gpt-5.2')
...
```

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel

model = OpenAIChatModel('gpt-5.2')
agent = Agent(model)
...
```

`OpenAIChatModel` is also what backs every [OpenAI-compatible provider](#openai-compatible-models) below — they all speak the Chat Completions wire format, so the same model class applies.

## OpenAI-compatible Models

Many providers and models are compatible with the OpenAI API, and can be used with `OpenAIChatModel` in Pydantic AI.
Before getting started, check the [installation and configuration](#install) instructions above.

To use another OpenAI-compatible API, you can set the `OPENAI_BASE_URL` and `OPENAI_API_KEY` environment variables, or make use of the `base_url` and `api_key` arguments from [`OpenAIProvider`][pydantic_ai.providers.openai.OpenAIProvider]:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.openai import OpenAIProvider

model = OpenAIChatModel(
    'model_name',
    provider=OpenAIProvider(
        base_url='https://<openai-compatible-api-endpoint>', api_key='your-api-key'
    ),
)
agent = Agent(model)
...
```

Various providers also have their own provider classes so that you don't need to specify the base URL yourself and you can use the standard `<PROVIDER>_API_KEY` environment variable to set the API key.
When a provider has its own provider class, you can use the `Agent("<provider>:<model>")` shorthand, e.g. `Agent("deepseek:deepseek-chat")` or `Agent("moonshotai:kimi-k2-0711-preview")`, instead of building the `OpenAIChatModel` explicitly. Similarly, you can pass the provider name as a string to the `provider` argument on `OpenAIChatModel` instead of instantiating the provider class explicitly.

### Model Profile

Sometimes, the provider or model you're using will have slightly different requirements than OpenAI's API or models, like having different restrictions on JSON schemas for tool definitions, or not supporting tool definitions to be marked as strict.

When using an alternative provider class provided by Pydantic AI, an appropriate model profile is typically selected automatically based on the model name.
If the model you're using is not working correctly out of the box, you can tweak various aspects of how model requests are constructed by providing your own [`ModelProfile`][pydantic_ai.profiles.ModelProfile] (for behaviors shared among all model classes) or [`OpenAIModelProfile`][pydantic_ai.profiles.openai.OpenAIModelProfile] (for behaviors specific to `OpenAIChatModel`):

```py
from pydantic_ai import Agent, InlineDefsJsonSchemaTransformer
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.profiles.openai import OpenAIModelProfile
from pydantic_ai.providers.openai import OpenAIProvider

model = OpenAIChatModel(
    'model_name',
    provider=OpenAIProvider(
        base_url='https://<openai-compatible-api-endpoint>.com', api_key='your-api-key'
    ),
    profile=OpenAIModelProfile(
        json_schema_transformer=InlineDefsJsonSchemaTransformer,  # Supported by any model class via the base ModelProfile
        openai_supports_strict_tool_definition=False,  # Supported by OpenAIChatModel and OpenAIResponsesModel
        openai_chat_supports_multiple_system_messages=False,  # Supported by OpenAIChatModel only — for strict providers (e.g. some vLLM/LiteLLM setups) that require exactly one initial system message
        openai_chat_supports_max_completion_tokens=False,  # Supported by OpenAIChatModel only — for providers (e.g. OpenRouter) that only accept the older `max_tokens` field instead of `max_completion_tokens`
    )
)
agent = Agent(model)
```

#### Models that accept only one leading system message

Some models are served with a chat template (applied server-side, for example by [vLLM](https://docs.vllm.ai/), [LiteLLM](#litellm), or TGI) that accepts only a single system message at the start of the conversation and rejects additional ones. Sending more than one fails with a `400` error such as `System message must be at the beginning.` or `Conversation roles must alternate ...`, seen with some newer Qwen, Mistral, Gemma, and Command-R models. It's easy to hit without intending to, since more than one leading system message can be produced in several ways.

Set `openai_chat_supports_multiple_system_messages=False` on the model's [`OpenAIModelProfile`][pydantic_ai.profiles.openai.OpenAIModelProfile] (as shown above) to merge the leading run of system messages into one, joined with two newlines, before the request is sent. The merge is lossless, so it's safe to enable whenever a backend rejects multiple system messages.

### DeepSeek

To use the [DeepSeek](https://deepseek.com) provider, first create an API key by following the [Quick Start guide](https://api-docs.deepseek.com/).

You can then set the `DEEPSEEK_API_KEY` environment variable and use [`DeepSeekProvider`][pydantic_ai.providers.deepseek.DeepSeekProvider] by name:

```python
from pydantic_ai import Agent

agent = Agent('deepseek:deepseek-chat')
...
```

Or initialise the model and provider directly:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.deepseek import DeepSeekProvider

model = OpenAIChatModel(
    'deepseek-chat',
    provider=DeepSeekProvider(api_key='your-deepseek-api-key'),
)
agent = Agent(model)
...
```

You can also customize any provider with a custom `http_client`:

```python
from httpx import AsyncClient

from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.deepseek import DeepSeekProvider

custom_http_client = AsyncClient(timeout=30)
model = OpenAIChatModel(
    'deepseek-chat',
    provider=DeepSeekProvider(
        api_key='your-deepseek-api-key', http_client=custom_http_client
    ),
)
agent = Agent(model)
...
```

### Alibaba Cloud Model Studio (DashScope)

To use Qwen models via [Alibaba Cloud Model Studio (DashScope)](https://www.alibabacloud.com/en/product/modelstudio), you can set the `ALIBABA_API_KEY` (or `DASHSCOPE_API_KEY`) environment variable and use [`AlibabaProvider`][pydantic_ai.providers.alibaba.AlibabaProvider] by name:

```python
from pydantic_ai import Agent

agent = Agent('alibaba:qwen-max')
...
```

Or initialise the model and provider directly:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.alibaba import AlibabaProvider

model = OpenAIChatModel(
    'qwen-max',
    provider=AlibabaProvider(api_key='your-api-key'),
)
agent = Agent(model)
...
```

The `AlibabaProvider` uses the international DashScope compatible endpoint `https://dashscope-intl.aliyuncs.com/compatible-mode/v1` by default. You can override this by passing a custom `base_url`:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.alibaba import AlibabaProvider

model = OpenAIChatModel(
    'qwen-max',
    provider=AlibabaProvider(
        api_key='your-api-key',
        base_url='https://dashscope.aliyuncs.com/compatible-mode/v1',  # China region
    ),
)
agent = Agent(model)
...
```

!!! note "Document input is not supported"
    The DashScope compatible-mode Chat Completions API does not accept document content parts, so passing a [`DocumentUrl`][pydantic_ai.messages.DocumentUrl] or document [`BinaryContent`][pydantic_ai.messages.BinaryContent] to an [`OpenAIChatModel`][pydantic_ai.models.openai.OpenAIChatModel] backed by [`AlibabaProvider`][pydantic_ai.providers.alibaba.AlibabaProvider] raises a `UserError`.

### Ollama

See [Ollama](ollama.md) for dedicated Ollama documentation, including structured output and Ollama Cloud limitations.

### Azure AI Foundry

To use [Azure AI Foundry](https://ai.azure.com/) as your provider, set `AZURE_OPENAI_ENDPOINT` to a URL whose path ends in `/v1` (for example `https://<resource>.openai.azure.com/openai/v1/` or `https://<resource>.services.ai.azure.com/openai/v1/`), set `AZURE_OPENAI_API_KEY`, and use [`AzureProvider`][pydantic_ai.providers.azure.AzureProvider] by name:

```python
from pydantic_ai import Agent

agent = Agent('azure:gpt-5.2')
...
```

Or initialise the model and provider directly:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.azure import AzureProvider

model = OpenAIChatModel(
    'gpt-5.2',
    provider=AzureProvider(
        azure_endpoint='https://your-resource.openai.azure.com/openai/v1/',
        api_key='your-api-key',
    ),
)
agent = Agent(model)
...
```

This targets the [Azure OpenAI v1 API](https://learn.microsoft.com/en-us/azure/ai-foundry/openai/api-version-lifecycle), which Microsoft recommends for all new projects. It also pairs naturally with the Responses API — see [Using Azure with the Responses API](#using-azure-with-the-responses-api) below.

[`AzureProvider`][pydantic_ai.providers.azure.AzureProvider] also recognises [Azure AI Foundry serverless model deployments](https://learn.microsoft.com/en-us/azure/ai-foundry/foundry-models/concepts/endpoints) at `https://<model>.<region>.models.ai.azure.com` and connects to them the same way.

#### Connecting to an existing `api-version`-based deployment

If your resource still uses the dated `api-version` API, pass `api_version` (or set the `OPENAI_API_VERSION` environment variable) and point `azure_endpoint` at the resource root instead:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.azure import AzureProvider

model = OpenAIChatModel(
    'gpt-5.2',
    provider=AzureProvider(
        azure_endpoint='https://your-resource.openai.azure.com/',
        api_version='2024-12-01-preview',
        api_key='your-api-key',
    ),
)
agent = Agent(model)
...
```

#### Using Azure with the Responses API

Azure AI Foundry also supports the OpenAI Responses API through [`OpenAIResponsesModel`][pydantic_ai.models.openai.OpenAIResponsesModel]. This is particularly recommended when working with document inputs ([`DocumentUrl`][pydantic_ai.DocumentUrl] and [`BinaryContent`][pydantic_ai.BinaryContent]), as Azure's Chat Completions API does not support these input types.

Use the `azure-responses:` prefix to select the Responses API by name (the `azure:` prefix uses the Chat Completions API):

```python
from pydantic_ai import Agent

agent = Agent('azure-responses:gpt-5.2')
...
```

!!! note
    Azure's Responses API doesn't yet support every feature of OpenAI's Responses API — for example, the web search built-in tool is unavailable, and there are limits around image editing and file uploads. See [Microsoft's Responses API docs](https://learn.microsoft.com/en-us/azure/foundry/openai/how-to/responses) for the current list. This applies whether you use the `azure-responses:` shorthand or construct `OpenAIResponsesModel` with `AzureProvider` directly.

Or initialise the model and provider directly:

??? example "Document processing with Azure using Responses API"
    ```python
    from pydantic_ai import Agent, BinaryContent
    from pydantic_ai.models.openai import OpenAIResponsesModel
    from pydantic_ai.providers.azure import AzureProvider

    pdf_bytes = b'%PDF-1.4 ...'  # Your PDF content

    model = OpenAIResponsesModel(
        'gpt-5.2',
        provider=AzureProvider(
            azure_endpoint='https://your-resource.openai.azure.com/openai/v1/',
            api_key='your-api-key',
        ),
    )
    agent = Agent(model)
    result = agent.run_sync([
        'Summarize this document',
        BinaryContent(data=pdf_bytes, media_type='application/pdf'),
    ])
    ```

### Vercel AI Gateway

To use [Vercel's AI Gateway](https://vercel.com/docs/ai-gateway), first follow the [documentation](https://vercel.com/docs/ai-gateway) instructions on obtaining an API key or OIDC token.

You can set the `VERCEL_AI_GATEWAY_API_KEY` and `VERCEL_OIDC_TOKEN` environment variables and use [`VercelProvider`][pydantic_ai.providers.vercel.VercelProvider] by name:

```python
from pydantic_ai import Agent

agent = Agent('vercel:anthropic/claude-sonnet-4-5')
...
```

Or initialise the model and provider directly:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.vercel import VercelProvider

model = OpenAIChatModel(
    'anthropic/claude-sonnet-4-5',
    provider=VercelProvider(api_key='your-vercel-ai-gateway-api-key'),
)
agent = Agent(model)
...
```

### MoonshotAI

Create an API key in the [Moonshot Console](https://platform.moonshot.ai/console).

You can set the `MOONSHOTAI_API_KEY` environment variable and use [`MoonshotAIProvider`][pydantic_ai.providers.moonshotai.MoonshotAIProvider] by name:

```python
from pydantic_ai import Agent

agent = Agent('moonshotai:kimi-k2-0711-preview')
...
```

Or initialise the model and provider directly:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.moonshotai import MoonshotAIProvider

model = OpenAIChatModel(
    'kimi-k2-0711-preview',
    provider=MoonshotAIProvider(api_key='your-moonshot-api-key'),
)
agent = Agent(model)
...
```

### GitHub Models

To use [GitHub Models](https://docs.github.com/en/github-models), you'll need a GitHub personal access token with the `models: read` permission.

You can set the `GITHUB_API_KEY` environment variable and use [`GitHubProvider`][pydantic_ai.providers.github.GitHubProvider] by name:

```python
from pydantic_ai import Agent

agent = Agent('github:xai/grok-3-mini')
...
```

Or initialise the model and provider directly:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.github import GitHubProvider

model = OpenAIChatModel(
    'xai/grok-3-mini',  # GitHub Models uses prefixed model names
    provider=GitHubProvider(api_key='your-github-token'),
)
agent = Agent(model)
...
```

GitHub Models supports various model families with different prefixes. You can see the full list on the [GitHub Marketplace](https://github.com/marketplace?type=models) or the public [catalog endpoint](https://models.github.ai/catalog/models).

### Perplexity

Follow the Perplexity [getting started](https://docs.perplexity.ai/guides/getting-started)
guide to create an API key, then initialise the model and provider directly:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.openai import OpenAIProvider

model = OpenAIChatModel(
    'sonar-pro',
    provider=OpenAIProvider(
        base_url='https://api.perplexity.ai',
        api_key='your-perplexity-api-key',
    ),
)
agent = Agent(model)
...
```

### Fireworks AI

Go to [Fireworks.AI](https://fireworks.ai/) and create an API key in your account settings.

You can set the `FIREWORKS_API_KEY` environment variable and use [`FireworksProvider`][pydantic_ai.providers.fireworks.FireworksProvider] by name:

```python
from pydantic_ai import Agent

agent = Agent('fireworks:accounts/fireworks/models/qwq-32b')
...
```

Or initialise the model and provider directly:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.fireworks import FireworksProvider

model = OpenAIChatModel(
    'accounts/fireworks/models/qwq-32b',  # model library available at https://fireworks.ai/models
    provider=FireworksProvider(api_key='your-fireworks-api-key'),
)
agent = Agent(model)
...
```

### Together AI

Go to [Together.ai](https://www.together.ai/) and create an API key in your account settings.

You can set the `TOGETHER_API_KEY` environment variable and use [`TogetherProvider`][pydantic_ai.providers.together.TogetherProvider] by name:

```python
from pydantic_ai import Agent

agent = Agent('together:meta-llama/Llama-3.3-70B-Instruct-Turbo-Free')
...
```

Or initialise the model and provider directly:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.together import TogetherProvider

model = OpenAIChatModel(
    'meta-llama/Llama-3.3-70B-Instruct-Turbo-Free',  # model library available at https://www.together.ai/models
    provider=TogetherProvider(api_key='your-together-api-key'),
)
agent = Agent(model)
...
```

### Heroku AI

To use [Heroku AI](https://www.heroku.com/ai), first create an API key.

You can set the `HEROKU_INFERENCE_KEY` and (optionally) `HEROKU_INFERENCE_URL` environment variables and use [`HerokuProvider`][pydantic_ai.providers.heroku.HerokuProvider] by name:

```python
from pydantic_ai import Agent

agent = Agent('heroku:claude-sonnet-4-5')
...
```

Or initialise the model and provider directly:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.heroku import HerokuProvider

model = OpenAIChatModel(
    'claude-sonnet-4-5',
    provider=HerokuProvider(api_key='your-heroku-inference-key'),
)
agent = Agent(model)
...
```

### LiteLLM

To use [LiteLLM](https://www.litellm.ai/), set the configs as outlined in the [doc](https://docs.litellm.ai/docs/set_keys). In `LiteLLMProvider`, you can pass `api_base` and `api_key`. The value of these configs will depend on your setup. For example, if you are using OpenAI models, then you need to pass `https://api.openai.com/v1` as the `api_base` and your OpenAI API key as the `api_key`. If you are using a LiteLLM proxy server running on your local machine, then you need to pass `http://localhost:<port>` as the `api_base` and your LiteLLM API key (or a placeholder) as the `api_key`.

To use custom LLMs, use `custom/` prefix in the model name.

Once you have the configs, use the [`LiteLLMProvider`][pydantic_ai.providers.litellm.LiteLLMProvider] as follows:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.litellm import LiteLLMProvider

model = OpenAIChatModel(
    'openai/gpt-5.2',
    provider=LiteLLMProvider(
        api_base='<api-base-url>',
        api_key='<api-key>'
    )
)
agent = Agent(model)

result = agent.run_sync('What is the capital of France?')
print(result.output)
#> The capital of France is Paris.
...
```

!!! note
    If your model rejects requests with more than one leading system message (for example, you
    see `System message must be at the beginning.`), set
    `openai_chat_supports_multiple_system_messages=False` on its profile. See
    [Models that accept only one leading system message](#models-that-accept-only-one-leading-system-message)
    for details.

### Nebius AI Studio

Go to [Nebius AI Studio](https://studio.nebius.com/) and create an API key.

You can set the `NEBIUS_API_KEY` environment variable and use [`NebiusProvider`][pydantic_ai.providers.nebius.NebiusProvider] by name:

```python
from pydantic_ai import Agent

agent = Agent('nebius:Qwen/Qwen3-32B-fast')
result = agent.run_sync('What is the capital of France?')
print(result.output)
#> The capital of France is Paris.
```

Or initialise the model and provider directly:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.nebius import NebiusProvider

model = OpenAIChatModel(
    'Qwen/Qwen3-32B-fast',
    provider=NebiusProvider(api_key='your-nebius-api-key'),
)
agent = Agent(model)
result = agent.run_sync('What is the capital of France?')
print(result.output)
#> The capital of France is Paris.
```

### OVHcloud AI Endpoints

To use OVHcloud AI Endpoints, you need to create a new API key. To do so, go to the [OVHcloud manager](https://ovh.com/manager), then in Public Cloud > AI Endpoints > API keys. Click on `Create a new API key` and copy your new key.

You can explore the [catalog](https://endpoints.ai.cloud.ovh.net/catalog) to find which models are available.

You can set the `OVHCLOUD_API_KEY` environment variable and use [`OVHcloudProvider`][pydantic_ai.providers.ovhcloud.OVHcloudProvider] by name:

```python
from pydantic_ai import Agent

agent = Agent('ovhcloud:gpt-oss-120b')
result = agent.run_sync('What is the capital of France?')
print(result.output)
#> The capital of France is Paris.
```

If you need to configure the provider, you can use the [`OVHcloudProvider`][pydantic_ai.providers.ovhcloud.OVHcloudProvider] class:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.ovhcloud import OVHcloudProvider

model = OpenAIChatModel(
    'gpt-oss-120b',
    provider=OVHcloudProvider(api_key='your-api-key'),
)
agent = Agent(model)
result = agent.run_sync('What is the capital of France?')
print(result.output)
#> The capital of France is Paris.
```

### SambaNova

To use [SambaNova Cloud](https://cloud.sambanova.ai/), you need to obtain an API key from the [SambaNova Cloud dashboard](https://cloud.sambanova.ai/dashboard).

SambaNova provides access to multiple model families including Meta Llama, DeepSeek, Qwen, and Mistral models with fast inference speeds.

You can set the `SAMBANOVA_API_KEY` environment variable and use [`SambaNovaProvider`][pydantic_ai.providers.sambanova.SambaNovaProvider] by name:

```python
from pydantic_ai import Agent

agent = Agent('sambanova:Meta-Llama-3.1-8B-Instruct')
result = agent.run_sync('What is the capital of France?')
print(result.output)
#> The capital of France is Paris.
```

Or initialise the model and provider directly:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.sambanova import SambaNovaProvider

model = OpenAIChatModel(
    'Meta-Llama-3.1-8B-Instruct',
    provider=SambaNovaProvider(api_key='your-api-key'),
)
agent = Agent(model)
result = agent.run_sync('What is the capital of France?')
print(result.output)
#> The capital of France is Paris.
```

For a complete list of available models, see the [SambaNova supported models documentation](https://docs.sambanova.ai/docs/en/models/sambacloud-models).

You can customize the base URL if needed:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.sambanova import SambaNovaProvider

model = OpenAIChatModel(
    'DeepSeek-R1-0528',
    provider=SambaNovaProvider(
        api_key='your-api-key',
        base_url='https://custom.endpoint.com/v1',
    ),
)
agent = Agent(model)
...
```

### Atlas Cloud

[Atlas Cloud](https://www.atlascloud.ai/) is an OpenAI-compatible API gateway that provides access to 300+ models from a single endpoint, including DeepSeek, Qwen, Claude, GPT, and Gemini.

Atlas Cloud doesn't have a dedicated provider class, so you can use it with [`OpenAIProvider`][pydantic_ai.providers.openai.OpenAIProvider] by setting the `base_url` and `api_key`:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.openai import OpenAIProvider

model = OpenAIChatModel(
    'deepseek-ai/deepseek-v4-pro',
    provider=OpenAIProvider(
        base_url='https://api.atlascloud.ai/v1',
        api_key='your-atlas-cloud-api-key',
    ),
)
agent = Agent(model)
...
```

### Rapid-MLX (Apple Silicon)

[Rapid-MLX](https://github.com/raullenchai/Rapid-MLX) is an OpenAI-compatible inference server for Apple Silicon, built on Apple's MLX framework.

```bash
pip install rapid-mlx
rapid-mlx serve mlx-community/Qwen3.5-4B-MLX-4bit
```

The server listens on `http://localhost:8000/v1` and implements the OpenAI chat completions API, so you can point [`OpenAIProvider`][pydantic_ai.providers.openai.OpenAIProvider] at it:

```python
from pydantic_ai import Agent
from pydantic_ai.models.openai import OpenAIChatModel
from pydantic_ai.providers.openai import OpenAIProvider

rapid_mlx_model = OpenAIChatModel(
    model_name='default',
    provider=OpenAIProvider(
        base_url='http://localhost:8000/v1',
        api_key='not-needed',
    ),
)
agent = Agent(rapid_mlx_model)
```