Azure managed identity with BYOK

This guide shows how to use the Azure Identity SDK's DefaultAzureCredential API to authenticate with Microsoft Foundry models through the Copilot SDK.

How it works

Microsoft Foundry's OpenAI-compatible endpoint accepts bearer tokens from Microsoft Entra ID in place of static API keys. The pattern is:

1. Use DefaultAzureCredential to obtain a token for the https://ai.azure.com/.default scope
2. Pass the token as the bearer_token in the BYOK provider config
3. Refresh the token before it expires (tokens are typically valid for ~1 hour)

Code samples

Prerequisites

Install the Azure Identity and Copilot SDK packages for your language:

dotnet add package GitHub.Copilot.SDK
dotnet add package Azure.Core

pip install github-copilot-sdk azure-identity

npm install @github/copilot-sdk @azure/identity

Basic usage

Get a token using DefaultAzureCredential and pass it as the bearer token in your provider configuration:

using Azure.Core;
using Azure.Identity;
using GitHub.Copilot;

DefaultAzureCredential credential = new(
    DefaultAzureCredential.DefaultEnvironmentVariableName);
AccessToken token = await credential.GetTokenAsync(
    new TokenRequestContext(new[] { "https://ai.azure.com/.default" }));

await using CopilotClient client = new();
string? foundryUrl = Environment.GetEnvironmentVariable("FOUNDRY_RESOURCE_URL");

await using CopilotSession session = await client.CreateSessionAsync(new SessionConfig
{
    Model = "gpt-5.5",
    Provider = new ProviderConfig
    {
        Type = "openai",
        BaseUrl = $"{foundryUrl!.TrimEnd('/')}/openai/v1/",
        BearerToken = token.Token,
        WireApi = "responses",
    },
});

AssistantMessageEvent? response = await session.SendAndWaitAsync(
    new MessageOptions { Prompt = "Hello from Managed Identity!" });
Console.WriteLine(response?.Data.Content);

import asyncio
import os

from azure.identity import DefaultAzureCredential
from copilot import CopilotClient
from copilot.session import PermissionHandler, ProviderConfig

SCOPE = "https://ai.azure.com/.default"

async def main():
    # Get a token using Managed Identity, Azure CLI, or other credential chain
    credential = DefaultAzureCredential(require_envvar=True)
    token = credential.get_token(SCOPE).token

    foundry_url = os.environ["FOUNDRY_RESOURCE_URL"]

    client = CopilotClient()
    await client.start()

    session = await client.create_session(
        on_permission_request=PermissionHandler.approve_all,
        model="gpt-5.5",
        provider=ProviderConfig(
            type="openai",
            base_url=f"{foundry_url.rstrip('/')}/openai/v1/",
            bearer_token=token,  # Short-lived bearer token
            wire_api="responses",
        ),
    )

    response = await session.send_and_wait("Hello from Managed Identity!")
    print(response.data.content)

    await client.stop()

asyncio.run(main())

import { DefaultAzureCredential } from "@azure/identity";
import { CopilotClient } from "@github/copilot-sdk";

const credential = new DefaultAzureCredential({
  requiredEnvVars: ["AZURE_TOKEN_CREDENTIALS"],
});
const tokenResponse = await credential.getToken(
  "https://ai.azure.com/.default"
);

const client = new CopilotClient();

const session = await client.createSession({
  model: "gpt-5.5",
  provider: {
    type: "openai",
    baseUrl: `${process.env.FOUNDRY_RESOURCE_URL}/openai/v1/`,
    bearerToken: tokenResponse.token,
    wireApi: "responses",
  },
});

const response = await session.sendAndWait({ prompt: "Hello!" });
console.log(response?.data.content);

await client.stop();

Token refresh for long-running applications

Bearer tokens expire (typically after ~1 hour). For servers or long-running agents, refresh the token before creating each session. The following Python example demonstrates this pattern:

from azure.identity import DefaultAzureCredential
from copilot import CopilotClient
from copilot.session import PermissionHandler, ProviderConfig

SCOPE = "https://ai.azure.com/.default"

class ManagedIdentityCopilotAgent:
    """Copilot agent that refreshes Microsoft Entra tokens for Microsoft Foundry."""

    def __init__(self, foundry_url: str, model: str = "gpt-5.5"):
        self.foundry_url = foundry_url.rstrip("/")
        self.model = model
        self.credential = DefaultAzureCredential(require_envvar=True)
        self.client = CopilotClient()

    def _get_provider_config(self) -> ProviderConfig:
        """Build a ProviderConfig with a fresh bearer token."""
        token = self.credential.get_token(SCOPE).token
        return ProviderConfig(
            type="openai",
            base_url=f"{self.foundry_url}/openai/v1/",
            bearer_token=token,
            wire_api="responses",
        )

    async def chat(self, prompt: str) -> str:
        """Send a prompt and return the response text."""
        # Fresh token for each session
        session = await self.client.create_session(
            on_permission_request=PermissionHandler.approve_all,
            model=self.model,
            provider=self._get_provider_config(),
        )

        response = await session.send_and_wait(prompt)
        await session.disconnect()

        return response.data.content if response else ""

Environment configuration

No API key environment variable is needed—authentication is handled by DefaultAzureCredential, which automatically supports:

• Managed Identity (system-assigned or user-assigned): for Azure-hosted apps
• Azure CLI (az login): for local development
• Environment variables (AZURE_CLIENT_ID, AZURE_TENANT_ID, AZURE_CLIENT_SECRET): for service principals
• Workload Identity: for Kubernetes

See the DefaultAzureCredential documentation for the full credential chain:

• .NET
• Python
• TypeScript

When to use this pattern

See also

• BYOK (bring your own key): Static API key configuration
• Backend services setup: Server-side deployment
• Azure Identity documentation