{
  "$defs": {
    "Expression": {
      "discriminator": {
        "mapping": {
          "call": "#/$defs/TreeCall",
          "conditional": "#/$defs/TreeConditional",
          "literal": "#/$defs/TreeLiteral",
          "memo": "#/$defs/TreeMemo",
          "tool_call": "#/$defs/TreeToolCall",
          "variable": "#/$defs/TreeVariable"
        },
        "propertyName": "type"
      },
      "oneOf": [
        {
          "$ref": "#/$defs/TreeLiteral"
        },
        {
          "$ref": "#/$defs/TreeVariable"
        },
        {
          "$ref": "#/$defs/TreeCall"
        },
        {
          "$ref": "#/$defs/TreeToolCall"
        },
        {
          "$ref": "#/$defs/TreeConditional"
        },
        {
          "$ref": "#/$defs/TreeMemo"
        }
      ]
    },
    "JsonValue": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "integer"
        },
        {
          "type": "number"
        },
        {
          "type": "boolean"
        },
        {
          "items": {
            "$ref": "#/$defs/JsonValue"
          },
          "type": "array"
        },
        {
          "additionalProperties": {
            "$ref": "#/$defs/JsonValue"
          },
          "type": "object"
        },
        {
          "type": "null"
        }
      ]
    },
    "TreeCall": {
      "additionalProperties": false,
      "description": "A call to a user-defined function.",
      "properties": {
        "type": {
          "const": "call",
          "default": "call",
          "title": "Type",
          "type": "string"
        },
        "function": {
          "minLength": 1,
          "pattern": "^[A-Za-z_][A-Za-z0-9_]*$",
          "title": "Function",
          "type": "string"
        },
        "arguments": {
          "items": {
            "$ref": "#/$defs/Expression"
          },
          "title": "Arguments",
          "type": "array"
        }
      },
      "required": [
        "function"
      ],
      "title": "TreeCall",
      "type": "object"
    },
    "TreeConditional": {
      "additionalProperties": false,
      "description": "A lazily evaluated conditional expression.",
      "properties": {
        "type": {
          "const": "conditional",
          "default": "conditional",
          "title": "Type",
          "type": "string"
        },
        "condition": {
          "$ref": "#/$defs/Expression"
        },
        "true_branch": {
          "$ref": "#/$defs/Expression"
        },
        "false_branch": {
          "$ref": "#/$defs/Expression"
        }
      },
      "required": [
        "condition",
        "true_branch",
        "false_branch"
      ],
      "title": "TreeConditional",
      "type": "object"
    },
    "TreeFunctionDefinition": {
      "additionalProperties": false,
      "description": "A globally declared user function with a lexical parameter scope.",
      "properties": {
        "type": {
          "const": "function_definition",
          "default": "function_definition",
          "title": "Type",
          "type": "string"
        },
        "name": {
          "minLength": 1,
          "pattern": "^[A-Za-z_][A-Za-z0-9_]*$",
          "title": "Name",
          "type": "string"
        },
        "params": {
          "items": {
            "minLength": 1,
            "pattern": "^[A-Za-z_][A-Za-z0-9_]*$",
            "type": "string"
          },
          "title": "Params",
          "type": "array"
        },
        "body": {
          "$ref": "#/$defs/Expression"
        }
      },
      "required": [
        "name",
        "body"
      ],
      "title": "TreeFunctionDefinition",
      "type": "object"
    },
    "TreeLiteral": {
      "additionalProperties": false,
      "description": "A JSON-compatible literal value.",
      "properties": {
        "type": {
          "const": "literal",
          "default": "literal",
          "title": "Type",
          "type": "string"
        },
        "value": {
          "$ref": "#/$defs/JsonValue"
        }
      },
      "required": [
        "value"
      ],
      "title": "TreeLiteral",
      "type": "object"
    },
    "TreeMemo": {
      "additionalProperties": false,
      "description": "Memoize one closed expression within a program invocation.",
      "properties": {
        "type": {
          "const": "memo",
          "default": "memo",
          "title": "Type",
          "type": "string"
        },
        "key": {
          "minLength": 1,
          "pattern": "^[A-Za-z_][A-Za-z0-9_]*$",
          "title": "Key",
          "type": "string"
        },
        "expression": {
          "$ref": "#/$defs/Expression"
        }
      },
      "required": [
        "key",
        "expression"
      ],
      "title": "TreeMemo",
      "type": "object"
    },
    "TreeProgram": {
      "additionalProperties": false,
      "description": "A version 2 program containing declarations and root expressions.",
      "properties": {
        "type": {
          "const": "program",
          "default": "program",
          "title": "Type",
          "type": "string"
        },
        "definitions": {
          "items": {
            "$ref": "#/$defs/TreeFunctionDefinition"
          },
          "title": "Definitions",
          "type": "array"
        },
        "body": {
          "items": {
            "$ref": "#/$defs/Expression"
          },
          "minItems": 1,
          "title": "Body",
          "type": "array"
        },
        "mode": {
          "default": "single",
          "enum": [
            "single",
            "parallel"
          ],
          "title": "Mode",
          "type": "string"
        },
        "name": {
          "anyOf": [
            {
              "type": "string"
            },
            {
              "type": "null"
            }
          ],
          "default": null,
          "title": "Name"
        },
        "description": {
          "anyOf": [
            {
              "type": "string"
            },
            {
              "type": "null"
            }
          ],
          "default": null,
          "title": "Description"
        },
        "schema_version": {
          "const": "2.0",
          "default": "2.0",
          "title": "Schema Version",
          "type": "string"
        }
      },
      "required": [
        "body"
      ],
      "title": "TreeProgram",
      "type": "object"
    },
    "TreeToolCall": {
      "additionalProperties": false,
      "description": "A call to an external provider tool.",
      "properties": {
        "type": {
          "const": "tool_call",
          "default": "tool_call",
          "title": "Type",
          "type": "string"
        },
        "tool": {
          "minLength": 1,
          "pattern": "^[A-Za-z_][A-Za-z0-9_]*$",
          "title": "Tool",
          "type": "string"
        },
        "arguments": {
          "patternProperties": {
            "^[A-Za-z_][A-Za-z0-9_]*$": {
              "$ref": "#/$defs/Expression"
            }
          },
          "propertyNames": {
            "minLength": 1
          },
          "title": "Arguments",
          "type": "object"
        }
      },
      "required": [
        "tool"
      ],
      "title": "TreeToolCall",
      "type": "object"
    },
    "TreeVariable": {
      "additionalProperties": false,
      "description": "A lexical variable reference.",
      "properties": {
        "type": {
          "const": "variable",
          "default": "variable",
          "title": "Type",
          "type": "string"
        },
        "name": {
          "minLength": 1,
          "pattern": "^[A-Za-z_][A-Za-z0-9_]*$",
          "title": "Name",
          "type": "string"
        }
      },
      "required": [
        "name"
      ],
      "title": "TreeVariable",
      "type": "object"
    }
  },
  "$ref": "#/$defs/TreeProgram",
  "description": "Validate the complete static contract of a version 2 program.",
  "title": "Treelang AST Program 2.0",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://cs0lar.github.io/treelang/latest/schemas/treelang-2.0.schema.json"
}