{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "urn:mujoco-web:robot:v1",
  "description": "V1 numeric robot payloads. Descriptor semantics and action epoch/lease/sequence are additionally validated at runtime. JSON numbers must be finite. No camera, lockstep or training support.",
  "oneOf": [
    { "$ref": "#/$defs/descriptor" },
    { "$ref": "#/$defs/action" },
    { "$ref": "#/$defs/observation" }
  ],
  "$defs": {
    "id": { "type": "string", "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.:-]{0,127}$" },
    "counter": { "type": "integer", "minimum": 0, "maximum": 9007199254740991 },
    "values": {
      "type": "object",
      "minProperties": 1,
      "maxProperties": 256,
      "propertyNames": { "$ref": "#/$defs/id" },
      "additionalProperties": { "type": "number" }
    },
    "channel": {
      "type": "object",
      "additionalProperties": false,
      "required": ["id", "unit", "mode", "min", "max"],
      "properties": {
        "id": { "$ref": "#/$defs/id" },
        "unit": { "enum": ["rad", "rad/s", "m", "m/s", "ratio", "N", "N.m"] },
        "mode": { "enum": ["position", "velocity", "effort", "opening"] },
        "min": { "type": "number" },
        "max": { "type": "number" }
      }
    },
    "channels": {
      "type": "array",
      "minItems": 1,
      "maxItems": 256,
      "items": { "$ref": "#/$defs/channel" }
    },
    "descriptor": {
      "type": "object",
      "additionalProperties": false,
      "required": [
        "protocolVersion",
        "profileId",
        "profileVersion",
        "modelFingerprint",
        "frame",
        "actionChannels",
        "observationChannels",
        "capabilities"
      ],
      "properties": {
        "protocolVersion": { "const": 1 },
        "profileId": { "$ref": "#/$defs/id" },
        "profileVersion": { "type": "integer", "minimum": 1, "maximum": 9007199254740991 },
        "modelFingerprint": { "type": "string", "pattern": "^[a-f0-9]{64}$" },
        "frame": { "const": "x-forward-y-left-z-up" },
        "actionChannels": { "$ref": "#/$defs/channels" },
        "observationChannels": { "$ref": "#/$defs/channels" },
        "capabilities": {
          "type": "object",
          "additionalProperties": false,
          "required": ["reset", "lockstep", "cameras", "training"],
          "properties": {
            "reset": { "type": "boolean" },
            "lockstep": { "const": false },
            "cameras": { "const": false },
            "training": { "type": "boolean" }
          }
        }
      }
    },
    "action": {
      "type": "object",
      "additionalProperties": false,
      "required": ["protocolVersion", "sessionId", "modelEpoch", "leaseId", "actionSeq", "values"],
      "properties": {
        "protocolVersion": { "const": 1 },
        "sessionId": { "$ref": "#/$defs/id" },
        "modelEpoch": { "$ref": "#/$defs/counter" },
        "leaseId": { "$ref": "#/$defs/id" },
        "actionSeq": { "type": "integer", "minimum": 1, "maximum": 9007199254740991 },
        "values": { "$ref": "#/$defs/values" }
      }
    },
    "observation": {
      "type": "object",
      "additionalProperties": false,
      "required": [
        "protocolVersion",
        "sessionId",
        "modelEpoch",
        "sequence",
        "simTime",
        "appliedActionSeq",
        "paused",
        "values"
      ],
      "properties": {
        "protocolVersion": { "const": 1 },
        "sessionId": { "$ref": "#/$defs/id" },
        "modelEpoch": { "$ref": "#/$defs/counter" },
        "sequence": { "$ref": "#/$defs/counter" },
        "simTime": { "type": "number", "minimum": 0 },
        "appliedActionSeq": { "$ref": "#/$defs/counter" },
        "paused": { "type": "boolean" },
        "values": { "$ref": "#/$defs/values" }
      }
    }
  }
}