{
  "version": "fak-route/v1",
  "default": {
    "members": [{ "model": "medium", "role": "primary" }],
    "reason": "no rule matched; fail-closed to the balanced mid-tier model"
  },
  "rules": [
    {
      "name": "guard-writes-vote",
      "match": { "aspect": "tool_call", "tool": "write_*" },
      "plan": {
        "members": [
          { "model": "guard-a", "weight": 1, "role": "primary" },
          { "model": "guard-b", "weight": 1, "role": "verifier" }
        ],
        "reduce": "vote",
        "reason": "write-shaped tool call: two guard models must agree (weighted majority) before the call proceeds"
      }
    },
    {
      "name": "legal-best-of",
      "match": { "aspect": "query", "labels": { "domain": "legal" } },
      "plan": {
        "members": [
          { "model": "drafter-a", "role": "drafter" },
          { "model": "drafter-b", "role": "drafter" },
          { "model": "judge", "role": "judge" }
        ],
        "reduce": "best_of",
        "scout": "tiny-classifier",
        "reason": "legal sub-query: two drafters, a judge scores, best answer wins; a tiny scout pre-classifies risk first"
      }
    },
    {
      "name": "retrieval-small",
      "match": { "aspect": "tool_call", "tool": "search_*" },
      "plan": {
        "members": [{ "model": "small" }],
        "reason": "cheap read-shaped tool call -> small/fast model"
      }
    },
    {
      "name": "fanout-concat",
      "match": { "aspect": "query", "labels": { "mode": "fanout" } },
      "plan": {
        "members": [
          { "model": "worker-a" },
          { "model": "worker-b" }
        ],
        "reduce": "concat",
        "reason": "fan-out gather: concatenate both workers' partial answers in member order"
      }
    },
    {
      "name": "hard-reasoning-step",
      "match": { "aspect": "step", "min_complexity": "high" },
      "plan": {
        "members": [{ "model": "large" }],
        "reason": "a hard reasoning step -> the large model (only the hard aspects pay the large-model price)"
      }
    }
  ]
}