Local Azure emulator

Developing against real Azure is slow, expensive, and requires a subscription. Topaz is a local Azure emulator that runs the services your application depends on — Storage, Key Vault, Service Bus, Event Hubs, Container Registry, and more — directly on your machine, without connecting to the cloud.

One process, every service

Most local Azure setups involve stitching together multiple tools: Azurite for storage, a third-party mock for Key Vault, the real Service Bus because nothing else exists. Each adds configuration, another process to manage, and another failure point in CI.

Topaz replaces the entire stack with a single binary:

topaz start --default-subscription 00000000-0000-0000-0000-000000000001

That one command gives you a running Azure environment — ARM control plane, storage, secrets, messaging, container registry — all on localhost.

The same code, locally

Topaz implements the actual Azure REST APIs, not simplified mocks. The SDK calls, authentication flow, and error handling you write against Topaz work identically in production — the only difference is the endpoint URI, which points at the Topaz-specific domain instead of Azure:

// Local: point at the Topaz-emulated vault
var client = new SecretClient(
    new Uri("https://myvault.keyvault.topaz.local.dev:8898"),
    new DefaultAzureCredential()
);
var secret = await client.GetSecretAsync("db-connection-string");

Everything else — credential resolution, retry behaviour, response parsing — behaves exactly as it would against a real vault. Swap the URI for https://myvault.vault.azure.net and the same code runs in production.

Infrastructure as code, locally

Topaz includes a full ARM control plane. That means Terraform's azurerm provider can target Topaz with a one-line configuration change:

provider "azurerm" {
  features {}
  metadata_host = "topaz.local.dev:8899"
  resource_provider_registrations = "none"
}

Your terraform apply creates real resources in Topaz — resource groups, storage accounts, Key Vaults, Service Bus namespaces — and terraform destroy cleans them up. No subscription. No cost. No drift between your local environment and what you declare in code.

Built for CI

Topaz ships as a Docker image, making it straightforward to add to any CI pipeline as a service container:

services:
  topaz:
    image: thecloudtheory/topaz-cli:latest
    ports:
      - "8899:8899"
      - "8898:8898"
      - "8891:8891"

Tests run against a fresh Topaz instance on every build — no shared state, no leftover resources, no subscription required.

What Topaz emulates

Service	Coverage
Azure Storage (Blob, Table)	Partial — core operations
Azure Key Vault (secrets)	Full secret lifecycle
Azure Service Bus	Namespaces, queues, topics
Azure Event Hubs	Namespaces, event hubs
Azure Container Registry	Full Docker Registry V2 + OCI
Managed Identity	Token issuance
ARM control plane	Resource groups, subscriptions, deployments
Entra ID	Applications, service principals, groups

See Supported services for the full operation-level breakdown.

Next steps

• Getting started — install Topaz and run it for the first time
• Terraform integration — configure azurerm to target Topaz
• Local Key Vault development — store and retrieve secrets locally
• Azurite alternative — detailed comparison with Azurite