Choose your balance with Fusion

Fusion reads your request and chooses a model, with automatic reasoning effort where supported. Now you can choose how strongly it favours price or quality, without maintaining your own model list.

Three profiles. One API.

• Fusion Cheap

  Spend less

  A stronger preference for lower estimated cost.

  minirouter/fusion:cheap

• Fusion

  Find a balance

  The default balance of benchmark quality and estimated cost.

  minirouter/fusion

• Fusion Max

  Aim higher

  Higher quality targets, with more room for cost.

  minirouter/fusion:max

A frontier for each task

Fusion compares models and reasoning efforts on benchmark quality, estimated request cost and latency. It sorts requests into coding, reasoning, writing or conversation, with four complexity levels for each.

Each profile has its own picks and fallbacks across those 16 combinations. The picks come from published settings, so they can improve as models, prices and evaluations change.

Benchmarks guide selection; they do not guarantee a better, cheaper or faster answer to every prompt.

Switch with one model ID

Use the profile you want on Chat Completions, Responses or Messages. Messages keeps the model’s default reasoning effort. Existing calls to minirouter/fusion keep the balanced profile.

curl https://api.minirouter.sh/v1/chat/completions \
  -H "Authorization: Bearer $MINIROUTER_API_KEY" \
  -H 'Content-Type: application/json' \
  --data '{
    "model": "minirouter/fusion:cheap",
    "max_tokens": 1024,
    "messages": [{ "role": "user", "content": "Fix this failing test." }]
  }'

Your explicit reasoning setting still wins. The x-minirouter-model response header names the model that served the request; x-minirouter-route-reason shows the task and tier when classification succeeds.