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DIAL SDK reference

DIAL SDK is a Python framework for building Custom Apps and model adapters that plug into the DIAL platform. It wraps FastAPI and handles the Unified API contract — streaming, error formatting, auth header propagation, and telemetry — so you can focus on application logic.

In this section​

  • DIALApp — register handlers, configure middleware, and serve the application
  • Chat completion — completion handlers, requests, responses, choices, and stages
  • Embeddings — implement and serve an embedding handler
  • Telemetry — emit OpenTelemetry traces, metrics, and logs

Installation​

Install the base package:

pip install aidial-sdk

To include OpenTelemetry support for traces, metrics, and logs:

pip install "aidial-sdk[telemetry]"

Python version: 3.10 or later.

What the SDK handles for you​

You implement one method. The SDK takes care of the contract around it:

  • The Unified API surface — it creates the routes DIAL Core calls, parses incoming requests, and serializes what you produce, whether the client asked for a streamed or a single response. See DIALApp and Chat completion.
  • Auth propagation — calls your app makes back to DIAL Core can carry the caller's key, so downstream deployments see the original user. See DIALApp.
  • Telemetry — optional OpenTelemetry traces, metrics, and logs. See Telemetry.

Quick example​

A minimal echo app that repeats the user's last message:

import uvicorn
from aidial_sdk import DIALApp
from aidial_sdk.chat_completion import ChatCompletion, Request, Response


class EchoApplication(ChatCompletion):
    async def chat_completion(
        self, request: Request, response: Response
    ) -> None:
        last_message = request.messages[-1]
        with response.create_single_choice() as choice:
            choice.append_content(last_message.text())


app = DIALApp()
app.add_chat_completion("echo", EchoApplication())

if __name__ == "__main__":
    uvicorn.run(app, port=5000)

Source repository​

The SDK source code and additional examples are available at github.com/epam/ai-dial-sdk.