Azure API Management vs. Tetrate Agent Router Enterprise: Which AI Gateway Fits?
Last updated: November 2026
The short answer
Azure API Management (APIM) is Microsoft’s API management service, and its AI gateway policies fit teams whose AI traffic stays in Azure. Tetrate Agent Router Enterprise is the Azure API Management AI gateway alternative for AI traffic that spans clouds, providers, coding assistants, and MCP servers. Many teams keep Azure API Management for APIs and add Agent Router Enterprise for AI.
Key facts
- Azure API Management’s AI gateway is a set of AI policies inside Azure API Management, not a separate product.
- Microsoft Foundry can create an AI gateway on the Basic v2 tier, free for the first 100,000 calls.
- Azure API Management self-hosted gateways get their configuration from an API Management instance in Azure. Microsoft lists them for production use in the Premium tier.
- Tetrate Agent Router Enterprise runs gateways in AWS, Azure, Google Cloud, on-premises, or at the edge, managed from one Tetrate-run management plane.
- Microsoft Foundry agents can use either gateway. Foundry bring your own model has been generally available since April 2026.
TL;DR
Azure API Management is Microsoft’s API management service, and it now includes AI gateway policies. It is a strong choice when your AI traffic stays in Azure and your team already runs API Management for its APIs.
Tetrate Agent Router Enterprise is a purpose-built AI gateway. Tetrate runs one management plane, and your gateways run in AWS, Azure, Google Cloud, on-premises, or at the edge. It tracks AI spend by person, team, agent, and project, runs guardrails inside your network, and governs MCP tools across teams.
Many teams use both. Keep Azure API Management for your APIs. Add Agent Router Enterprise for AI traffic that crosses clouds, providers, coding tools, and MCP servers. Microsoft Foundry supports both as a gateway for its agents. See the full 2026 enterprise AI gateway comparison.
Azure API Management AI gateway
Azure API Management is made up of an API gateway, a management plane, and a developer portal. Microsoft hosts and manages these parts by default.
The AI gateway is a set of AI features inside Azure API Management. Microsoft says it is not a separate offering. The AI gateway features include:
- Token limits and token metrics for model APIs
- Semantic caching with Azure Managed Redis or another compatible cache
- Prompt checks that call the Azure AI Content Safety service
- Load balancing and circuit breakers across model backends
- MCP servers created from existing REST APIs, and pass-through to existing MCP servers
- Agent-to-agent (A2A) API support
Microsoft has also built the AI gateway into Microsoft Foundry, in preview. A new AI gateway created from Foundry runs on the Basic v2 tier and is free for the first 100,000 calls. Microsoft lists a new AI Gateway tier for API Management, in preview, with pricing not yet published.
Product scope
Both products give applications one OpenAI-compatible entry point for many models. The difference is scope.
Azure API Management manages all kinds of APIs, such as REST, GraphQL, and SOAP, and adds AI policies on top. Its control plane is an API Management instance in Azure. That is the classic API gateway pattern with AI features added.
Tetrate Agent Router Enterprise is built only for AI traffic: models, agents, and MCP tools. It is built on Agent Router, the open source AI gateway (formerly Envoy AI Gateway) that Tetrate co-created with Bloomberg and that now belongs to the Agentic AI Foundation. See the Agent Router Enterprise product page.
Azure API Management incumbents
Problem. A platform team runs Azure API Management for its APIs. AI use grows across teams. Some teams call Azure OpenAI. Others call Anthropic or OpenAI directly, use AWS Bedrock or Google Vertex AI, run models on their own GPUs, or use coding assistants on laptops. Finance asks for AI spend by team, and security asks which agent can call which tool.
Solution. Keep Azure API Management for APIs. Put AI traffic behind Tetrate Agent Router Enterprise, with gateways in each cloud and region where the AI traffic runs. Point Microsoft Foundry agents at Agent Router through Foundry’s bring your own model gateway connection, which Microsoft made generally available in April 2026.
Outcome. One set of AI rules, one spend report by person, team, and agent, and one MCP catalog across every cloud and provider. The API Management setup stays as it is.
Head-to-head comparison
| Azure API Management | Tetrate Agent Router Enterprise | |
|---|---|---|
| Architecture | API management service with AI policies added | Purpose-built AI gateway on the Agent Router data plane |
| Control plane | An API Management instance in Azure | Run by Tetrate. Gateways keep serving traffic if the management plane is unreachable |
| Gateways outside Azure | Self-hosted gateway. Microsoft lists it for production use in the Premium tier. Some features, such as semantic caching, are not supported on the self-hosted gateway | Data planes in AWS, Azure, Google Cloud, on-premises, or at the edge, with outbound-only connections |
| Model routing | Load balancing, priority, and circuit breakers across backends | Rules, weights, fallbacks, and smart routing. Every routing decision is recorded |
| Cost attribution | Token metrics sent to Application Insights, with up to 5 custom dimensions per policy | Spend by person, team, agent, and project, with budgets checked before each request, and showback and chargeback |
| Runtime guardrails | Prompt checks through the Azure AI Content Safety service | Classifiers in the data plane, PII and secrets redaction before data leaves your network, and your own guardrail services |
| MCP and tool governance | Turns REST APIs into MCP servers and passes traffic to existing MCP servers | MCP profiles that combine servers, scope them to projects, and govern access, with step-up authorization through Ory |
| Policy authoring | XML policies attached to APIs | Declared once in the console or admin API. Every gateway in scope applies the policy |
| Coding assistants | Custom setup | VS Code extension, GitHub Copilot CLI, Visual Studio, Claude Code, and Tetrate Desktop |
| Caching | Semantic caching with Redis | Provider prompt caching. No gateway-owned prompt cache |
Pricing models
Azure API Management prices by service tier and scale unit. The classic tiers are Developer, Basic, Standard, and Premium, and the v2 tiers are Basic v2, Standard v2, and Premium v2. Microsoft lists the self-hosted gateway for production use in the Premium tier. Pricing for the new AI Gateway tier is not yet published.
Tetrate Agent Router Enterprise uses a fixed subscription based on features, deployment footprint, and support tier. There is no per-token or per-request charge, so the bill does not change when AI usage grows.
Deployment architecture
With Azure API Management, every self-hosted gateway connects to an API Management instance in Azure for its configuration. Microsoft always provisions a managed gateway in Azure as part of each instance.
With Tetrate Agent Router Enterprise, Tetrate runs the management plane outside the request path. Each data plane keeps a local copy of the rules and connects outward to Tetrate. If the management plane is unreachable, AI traffic keeps flowing. Prompts and responses stay in your network when the data plane runs there.
Gateway comparison
| Gateway | Management run by | AI traffic stays in your network | Same rules across clouds |
|---|---|---|---|
| Tetrate Agent Router Enterprise | Tetrate | Yes, with data planes in your network | Yes, one management plane for every data plane |
| Azure API Management | Microsoft, as an API Management instance in your Azure subscription | Yes, with self-hosted gateways in the Premium tier | Yes, from one API Management instance in Azure |
Performance note
In an independent Broadcom (VMware Cloud Foundation) test of the Agent Router data plane, then named Envoy AI Gateway, gateway overhead was about 2 ms per request, about 0.01% of end-to-end latency under real GPU inference. See the AI gateway benchmarks page.
Azure API Management fit
Choose Azure API Management when:
- Your AI traffic stays in Azure and will stay there.
- You already run Azure API Management for your APIs, with a developer portal.
- You want Entra ID and Azure Monitor with no extra setup.
- You need semantic caching at the gateway.
- You want to start with the free AI gateway that Microsoft Foundry creates.
Agent Router Enterprise fit
Choose Tetrate Agent Router Enterprise when:
- AI traffic runs in more than one cloud, region, or data center, or on your own GPUs.
- Teams call model providers directly, outside Azure.
- Finance needs AI spend by person, team, agent, and project, with budgets that stop spend before it happens.
- Security needs guardrails and PII redaction inside your own network.
- You run many MCP servers and need to control which agent can use which tool.
- Developers use coding assistants such as GitHub Copilot, Claude Code, or Codex, and you want one key and one bill.
- You want a fixed price with no usage charge.
Agent Router Enterprise
Tetrate Agent Router Enterprise routes AI agent traffic across providers and your own models, with smart routing, policy, cost controls, and audit on every request, in cloud, on-prem, or edge.
Frequently asked questions
What is the Azure API Management AI gateway? The AI gateway is a set of AI policies inside Azure API Management, Microsoft’s API management service. The policies add token limits, token metrics, semantic caching, content safety checks, and load balancing for model APIs, plus MCP and A2A support.
Can I run Tetrate Agent Router Enterprise alongside Azure API Management? Yes. Many teams keep Azure API Management for REST, GraphQL, and SOAP APIs and use Tetrate Agent Router Enterprise for AI traffic. Microsoft Foundry supports both as a gateway for Foundry agents. Applications reach Agent Router Enterprise through an OpenAI-compatible endpoint, so adding it is usually a base URL change and a new key.
Does Microsoft Foundry work with Tetrate Agent Router Enterprise? Yes. Microsoft made bring your own model generally available for Foundry Agent Service in April 2026. Foundry prompt agents can use models behind Azure API Management or any third-party AI model gateway, including Tetrate Agent Router Enterprise. Every model call from the agent then passes through the gateway for policy, cost tracking, and guardrails.
Can Azure API Management run outside Azure? Yes, through the self-hosted gateway, which Microsoft lists for production use in the Premium tier. Each self-hosted gateway gets its configuration from an API Management instance in Azure, and Microsoft always provisions a managed gateway in Azure as well. Some features, such as semantic caching, are not supported on the self-hosted gateway.
Should I replace Azure API Management with Tetrate Agent Router Enterprise? Usually not. Keep Azure API Management for your REST, GraphQL, and SOAP APIs and for AI traffic that stays in Azure. Add Tetrate Agent Router Enterprise for AI traffic that crosses clouds, providers, coding tools, and MCP servers. Most teams start with one AI use case and grow from there.
Does Azure have an AI gateway? Yes. Microsoft offers AI gateway features in Azure API Management. They include token limits, token metrics, semantic caching, content safety checks through Azure AI Content Safety, and load balancing for model APIs. Microsoft has also built the AI gateway into Microsoft Foundry, in preview, and lists a new AI Gateway tier for API Management, also in preview.
How is the Azure API Management AI gateway priced? Azure API Management prices by service tier and scale unit. A new AI gateway created from Microsoft Foundry runs on Basic v2 and is free for the first 100,000 calls. Microsoft lists the self-hosted gateway for production use in the Premium tier. Pricing for the new AI Gateway tier is not yet published. Tetrate Agent Router Enterprise uses a fixed subscription with no usage charge.
What is the best Azure API Management alternative for multi-cloud AI traffic? Tetrate Agent Router Enterprise is built for multi-cloud AI traffic. It runs gateways in AWS, Azure, Google Cloud, on-premises, and at the edge from one Tetrate-run management plane. Cost attribution by person, team, and agent, guardrails inside your network, and MCP governance are built in, with a fixed subscription and no usage charge.
Compare other gateways: OpenRouter · Portkey · Bifrost · Cloudflare AI Gateway · Kong AI Gateway · Agent Router (open source) · LiteLLM
See the full 2026 enterprise AI gateway comparison.
Sources
- AI gateway capabilities in Azure API Management
- API Management gateways overview and feature comparison
- API Management key concepts
- API Management pricing
- llm-emit-token-metric policy
- AI Gateway in Azure API Management is now available in Microsoft Foundry (preview)
- Bring your own model to Foundry Agent Service
Microsoft features checked on 13 November 2026.
Learn more about Tetrate Agent Router Enterprise — enterprise AI agent routing with smart routing, policy, cost controls, and audit across every gateway.
