{
  "schema_version": "1.0",
  "id": "relation.joint.fixed",
  "version": "1.0.0",
  "relation_type": "fixed",
  "endpoint_rules": {
    "source_port": "port.rotation.coaxial",
    "target_port": "port.mount.stationary",
    "axis_relation": "mechanism_defined"
  },
  "constraint_rules": ["one_endpoint_is_grounded", "fixed_speed_is_zero"],
  "kinematic_effect": {"equation": "omega_source = omega_target = 0"},
  "capability_refs": [
    "capability.kinematics.graph",
    "capability.validation.fixed"
  ],
  "maturity": "production"
}