The MCP tooling landscape just got a subtle but significant shift. On October 7, 2026, Agent Router v1.2.0 shipped a new prefixMode: Never setting for MCP tool names. This brings it into functional parity with agentgateway, which already offers Conditional, Always, and Never modes. However, the devil is in the defaults. While agentgateway defaults to Conditional—meaning single-target backends expose bare tool names—Agent Router retains an Always default, forcing prefixes until you explicitly opt out.

The Naming Collision Problem

prefixMode dictates whether a gateway namespaces MCP tool names with their target server. This is critical when multiplexing multiple servers behind one endpoint to prevent collisions, such as two servers both exposing a fetch tool. agentgateway’s Conditional mode is smart: it only adds prefixes when a backend has more than one target. If you run a single-target backend, your clients see clean, bare names. Agent Router’s default Always mode prefixes everything, even single targets, which can break clients expecting plain names unless you manually set Never.

Agent Router Renaming and New Features

Context matters here. Agent Router is simply Envoy AI Gateway rebranded, effective with v1.2.0. The GitHub org moved to theagentrouter/agent-router and the site is now theagentrouter.ai, but the underlying API group aigateway.envoyproxy.io and CRDs remain unchanged. Beyond the rename, v1.2.0 introduces caller-supplied credentials with injectionPolicy: IfNotPresent, allowing clients to forward their own tokens while the gateway injects keys only when missing. It also adds policy merging for SecurityPolicy and BackendTrafficPolicy, plus new backend schemas for AWSOpenAI and TypeSafe’s Jev System One model, though streaming remains unsupported for TypeSafe.

Operational Gotchas and Spend Limits

For agentgateway users, a major operational trap exists with the default Conditional mode: adding a second target to an existing backend instantly changes every tool name from bare to prefixed. This breaks clients calling the old names. The fix is to either update clients to use prefixed names or switch to prefixMode: Never, ensuring no name collisions across targets. Regarding spend controls, agentgateway standalone (v1.5.0+) supports per-key USD budgets via a database, while Kubernetes open-source mode limits caps to tokens only. Dollar budgets on Kubernetes require the EnterpriseAgentgatewayBudget CRD from Solo Enterprise.

Key Takeaways

  • Agent Router v1.2.0 adds prefixMode: Never, matching agentgateway’s feature set but keeping an Always default.
  • agentgateway defaults to Conditional, exposing bare names for single-target backends out of the box.
  • Envoy AI Gateway is now Agent Router, joining the Agentic AI Foundation on September 9, 2026.
  • Adding a second target to an agentgateway backend changes tool names, requiring client updates or a mode switch to Never.
  • Agent Router v1.2.0 introduces TypeSafe Jev backend support and caller-supplied credential injection.

The Bottom Line

If you prioritize clean tool names for single-backend setups, agentgateway’s Conditional default is superior to Agent Router’s Always default. But if you’re migrating from Envoy AI Gateway, the rebrand is purely cosmetic; the API stability is reassuring, though you must manually adjust prefixMode to match agentgateway’s out-of-the-box behavior.