Azure Identity SDK for Rust

Authentication library for Azure SDK clients using Microsoft Entra ID (formerly Azure AD).

Installation

cargo add azure_identity

Environment Variables

# Service Principal (for production/CI)
AZURE_TENANT_ID=<your-tenant-id>
AZURE_CLIENT_ID=<your-client-id>
AZURE_CLIENT_SECRET=<your-client-secret>

# User-assigned Managed Identity (optional)
AZURE_CLIENT_ID=<managed-identity-client-id>

DeveloperToolsCredential

The recommended credential for local development. Tries developer tools in order (Azure CLI, Azure Developer CLI):

use azure_identity::DeveloperToolsCredential;
use azure_security_keyvault_secrets::SecretClient;

let credential = DeveloperToolsCredential::new(None)?;
let client = SecretClient::new(
    "https://my-vault.vault.azure.net/",
    credential.clone(),
    None,
)?;

Credential Chain Order

Order	Credential	Environment
1	AzureCliCredential	az login
2	AzureDeveloperCliCredential	azd auth login

Credential Types

Credential	Usage
DeveloperToolsCredential	Local development - tries CLI tools
ManagedIdentityCredential	Azure VMs, App Service, Functions, AKS
WorkloadIdentityCredential	Kubernetes workload identity
ClientSecretCredential	Service principal with secret
ClientCertificateCredential	Service principal with certificate
AzureCliCredential	Direct Azure CLI auth
AzureDeveloperCliCredential	Direct azd CLI auth
AzurePipelinesCredential	Azure Pipelines service connection
ClientAssertionCredential	Custom assertions (federated identity)

ManagedIdentityCredential

For Azure-hosted resources:

use azure_identity::ManagedIdentityCredential;

// System-assigned managed identity
let credential = ManagedIdentityCredential::new(None)?;

// User-assigned managed identity
let options = ManagedIdentityCredentialOptions {
    client_id: Some("<user-assigned-mi-client-id>".into()),
    ..Default::default()
};
let credential = ManagedIdentityCredential::new(Some(options))?;

ClientSecretCredential

For service principal with secret:

use azure_identity::ClientSecretCredential;

let credential = ClientSecretCredential::new(
    "<tenant-id>".into(),
    "<client-id>".into(),
    "<client-secret>".into(),
    None,
)?;

Best Practices

1. Use DeveloperToolsCredential for local dev — automatically picks up Azure CLI
2. Use ManagedIdentityCredential in production — no secrets to manage
3. Clone credentials — credentials are Arc-wrapped and cheap to clone
4. Reuse credential instances — same credential can be used with multiple clients
5. Use tokio feature — cargo add azure_identity --features tokio

Reference Links

Resource	Link
API Reference	https://docs.rs/azure_identity
Source Code	https://github.com/Azure/azure-sdk-for-rust/tree/main/sdk/identity/azure_identity
crates.io	https://crates.io/crates/azure_identity