Auto Router

What the new Auto Router is

The Auto Router is OpenRouter's flagship general-purpose router. Instead of you choosing a model, it chooses one for each request. The new generation is rebuilt from the ground up on a new technical foundation that outperforms the old router by up to 4× depending on the benchmark.

The new routers choose models by weighing eleven factors about each request and combining them with live pricing, provider health, and cache status. This means the routing decision reflects both the content of the request and the current state of the model market on OpenRouter.

• General-purpose router: openrouter/auto
• Coding-specialized router: openrouter/auto-code (Auto Code)
• Experimental release channel: openrouter/auto-beta (Auto Beta)

What changed compared with the previous generation

The headline change is a full rebuild. OpenRouter says the new router outperforms the old one by up to 4× depending on the benchmark, and the routing step is 3× faster at the p90 in its live test (0.65s against 1.96s).

Behavior during the beta period also improved: the router stayed on the same model for nearly nine of every ten agent turns, invalid tool calls were 4× lower, and agentic responses were cut off half as often. These are OpenRouter's reported beta results, not guarantees for every workload.

• Up to 4× better performance depending on the benchmark
• 3× faster routing step at p90 (0.65s vs 1.96s)
• Stayed on the same model for nearly nine of every ten agent turns during beta
• 4× fewer invalid tool calls and half as many cut-off agentic responses during beta

Auto Code (openrouter/auto-code) for coding work

Auto Code is a new router specialized for coding work, launched alongside the flagship general-purpose Auto Router. Across five benchmarks, OpenRouter reports that Auto Code scores in line with Claude Opus 5.5 while costing 74% less per task.

If your workload is primarily code generation, editing, or agentic coding, Auto Code is the more targeted option. For general-purpose tasks, openrouter/auto remains the flagship choice.

• Use openrouter/auto-code when the task is coding-focused
• Use openrouter/auto for general-purpose routing
• Auto Code is reported to score in line with Claude Opus 5.5 on five benchmarks at 74% lower cost per task

Getting started and switching from the old router

Switching from the old Auto Router requires no changes. The slug is still openrouter/auto, and the auto-router plugin settings cost_tier, allowed_models, and excluded_models still work.

If you want to test routing changes before they reach the stable router, use Auto Beta (openrouter/auto-beta). It is the experimental release channel where routing changes land before graduating to openrouter/auto. Its per-request settings must use the plugin id auto-beta-router.

• Keep using openrouter/auto; no slug change is needed
• Existing cost_tier, allowed_models, and excluded_models settings continue to work
• For experimental routing, use openrouter/auto-beta with plugin id auto-beta-router

Cost behavior and restoring previous cost performance

The default policy of the new Auto Router costs more per task than the previous generation. OpenRouter made this decision to return to pricing closer to where Auto was a few months ago in order to introduce a greater variety of models.

If you preferred the previous cost behavior, you can set cost_tier to low to get similar cost performance. This is a configuration choice, not an automatic change.

• Default policy costs more per task than the previous generation
• Set cost_tier to low to get similar cost performance to the previous behavior
• The change is intended to allow a greater variety of models

Seeing why the router picked a model

A routing insights panel appears beside each reply in the chatroom, showing why the router picked that model. The same analysis is available via the API when you enable router metadata.

This is useful for debugging unexpected model choices and for understanding how the eleven factors and live signals influenced a decision.

• Chatroom: routing insights panel beside each reply
• API: enable router metadata to get the same analysis

Documented limitations

The router requires conversational input: a string or message list in input on the Responses API, or messages on Chat Completions, not the legacy prompt field. It is available only in the global data region.

Do not combine openrouter/auto with another router model in the same request. Also note that the deprecated settings cost_quality_tradeoff and pin_model belonged to the previous generation; requests sending them still succeed, but the current router does not use them.

• Requires conversational input (input string or message list; messages on Chat Completions)
• Global data region only
• Do not combine with another router model in the same request
• cost_quality_tradeoff and pin_model are accepted but ignored

Questions