Azure Identity library for Rust

Microsoft Entra ID authentication for Azure SDK clients.

Use this skill when:

• An app needs to authenticate to Azure services from Rust
• You need DeveloperToolsCredential for local development
• You need ManagedIdentityCredential for Azure-hosted workloads
• You need service principal auth with secret or certificate

IMPORTANT: Only use official azure_* crates published by the azure-sdk crates.io user. Do NOT use the deprecated azure_sdk_* crates (MindFlavor/AzureSDKForRust) or community crates. Official crates use underscores in names and none have version 0.21.0.

Note: The Rust SDK does not have DefaultAzureCredential. Use DeveloperToolsCredential for local development and ManagedIdentityCredential for production.

// Incorrect in Rust: this type does not exist in azure_identity
use azure_identity::DefaultAzureCredential;

Installation

cargo add azure_identity azure_core tokio

If your code uses azure_core types directly, add azure_core to Cargo.toml. If you only use service-crate re-exports, direct azure_core dependency is optional.

Environment Variables

AZURE_TENANT_ID=<your-tenant-id>         # Required for service principal auth
AZURE_CLIENT_ID=<your-client-id>         # Required for service principal or user-assigned managed identity
AZURE_CLIENT_SECRET=<your-client-secret> # Required for ClientSecretCredential

Authentication

DeveloperToolsCredential (Local Development)

Tries Azure CLI then Azure Developer CLI:

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

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Local dev: DeveloperToolsCredential. Production: use ManagedIdentityCredential.
    let credential = DeveloperToolsCredential::new(None)?;
    let client = SecretClient::new(
        "https://<vault-name>.vault.azure.net/",
        credential.clone(),
        None,
    )?;

    let secret = client.get_secret("secret-name", None).await?.into_model()?;
    println!("Secret: {:?}", secret.value);
    Ok(())
}

Ensure you are logged in:

az login        # Azure CLI
azd auth login  # or Azure Developer CLI

Order	Credential	Login Command
1	AzureCliCredential	az login
2	AzureDeveloperCliCredential	azd auth login

ManagedIdentityCredential (Production)

For Azure-hosted resources (VMs, App Service, Functions, AKS):

use azure_identity::ManagedIdentityCredential;

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

ClientSecretCredential (Service Principal)

For CI/CD pipelines and service accounts:

use azure_identity::ClientSecretCredential;

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

Credential Types

Credential	Use Case
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)

Best Practices

1. Use cargo add to manage dependencies, never edit Cargo.toml directly. Add and remove Rust SDK dependencies with cargo commands instead of manual manifest edits.
2. Add azure_core only when importing azure_core types directly. If your code imports azure_core::http::Url, azure_core::http::RequestContent, or azure_core::error::ErrorKind, include azure_core; otherwise a direct dependency is optional.
3. Use DeveloperToolsCredential for local dev, ManagedIdentityCredential for production — Rust does not provide a single DefaultAzureCredential type
4. Never hardcode credentials — use environment variables for service principals
5. Clone credentials — pass credential.clone() when constructing multiple clients; credentials are Arc-wrapped
6. Reuse clients — clients are thread-safe; create once, share across tasks
7. Assign RBAC roles — ensure the identity has appropriate roles for the target service (e.g., "Key Vault Secrets User" for secret reads)
8. Run cargo clippy -- -D warnings when the prompt, eval, or CI expects lint-clean output; Rust trajectory graders can fail on style lints even after compiler errors are fixed
9. Future-proof #[non_exhaustive] SDK models — when constructing SDK model/options structs, end the initializer with ..Default::default() (add #[allow(clippy::needless_update)]) and use a _ wildcard arm when matching SDK enums, so new service-added fields/variants don't break your build

Reference Links

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