config.schema.json

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$ref": "#/$defs/Config",
  "$defs": {
    "Config": {
      "properties": {
        "to": { "type": "string", "enum": ["github.com"] },
        "from": { "type": "string" },
        "orgs": {
          "additionalProperties": {
            "items": { "$ref": "#/$defs/MirrorDefinition" },
            "type": "array"
          },
          "type": "object"
        },
        "defaults": { "$ref": "#/$defs/MirrorDefaults" }
      },
      "additionalProperties": false,
      "type": "object",
      "required": ["to", "from", "orgs"]
    },
    "MirrorDefaults": {
      "properties": {
        "except": { "items": { "type": "string" }, "type": "array" },
        "only": { "items": { "type": "string" }, "type": "array" },
        "prefix": { "type": "string" },
        "suffix": { "type": "string" },
        "topics": { "items": { "type": "string" }, "type": "array" },
        "subgroups": {
          "properties": { "flatten": { "type": "string" } },
          "additionalProperties": false,
          "type": "object",
          "required": ["flatten"]
        }
      },
      "additionalProperties": false,
      "type": "object"
    },
    "MirrorDefinition": {
      "properties": {
        "from": { "type": "string" },
        "except": { "items": { "type": "string" }, "type": "array" },
        "only": { "items": { "type": "string" }, "type": "array" },
        "prefix": { "type": "string" },
        "suffix": { "type": "string" },
        "topics": { "items": { "type": "string" }, "type": "array" },
        "subgroups": {
          "properties": { "flatten": { "type": "string" } },
          "additionalProperties": false,
          "type": "object",
          "required": ["flatten"]
        }
      },
      "additionalProperties": false,
      "type": "object",
      "required": ["from"]
    }
  }
}