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

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

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