Custom Providers
Create your own providers and use them like the built-in providers. You can
choose to implement either a ChatModel or an EmbeddingsModel or both.
Dependencies
You do not need to depend on the dartantic_ai package to create a custom
provider. The dartantic_interface package is all you need.
dependencies:
dartantic_interface: ^VERSION
Creating a Custom Provider
Here's a simple example of a custom provider that exposes a ChatModel:
class EchoProvider extends Provider<ChatModelOptions, EmbeddingsModelOptions> {
EchoProvider()
: super(
name: 'echo',
displayName: 'Echo',
defaultModelNames: {ModelKind.chat: 'echo'},
caps: {ProviderCaps.chat},
);
@override
ChatModel<ChatModelOptions> createChatModel({
String? name,
List<Tool<Object>>? tools,
double? temperature,
ChatModelOptions? options,
}) => EchoChatModel(
name: name ?? defaultModelNames[ModelKind.chat]!,
defaultOptions: options,
);
// ... other required methods
}
Custom Model
Here's a minimal chat model example:
class EchoChatModel extends ChatModel<ChatModelOptions> {
EchoChatModel({required super.name, ChatModelOptions? defaultOptions})
: super(defaultOptions: defaultOptions ?? const ChatModelOptions());
@override
Stream<ChatResult<ChatMessage>> sendStream(
List<ChatMessage> messages, {
ChatModelOptions? options,
JsonSchema? outputSchema,
}) {
// Echo back the last user message
return Stream.fromIterable([
ChatResult<ChatMessage>(
output: ChatMessage.fromJson(
messages.last.toJson()..['role'] = 'model',
),
),
]);
}
}
With your custom provider, you can use it with an agent:
final agent = Agent.forProvider(EchoProvider());
final result = await agent.send('Hello!');
print(result.output); // Echoes back your input
Dynamic Provider Registration
If you'd like to participate in the named lookup of providers, you can add your custom provider to the provider map:
// Add your custom provider to the registry
Provider.providerMap['echo'] = EchoProvider();
// Use it like any built-in provider
final agent = Agent('echo');
final result = await agent.send('Hello!');
print(result.output); // Echoes back your input
Next Steps
- Providers - Current built-in providers
- Environment Setup - Configure API keys