iflytek/astron-agent · error · Exception

Failed to convert literal value

Error message

Failed to convert literal value {input_key} to type {json_input_type}, literal value: {input_content_org}

What it means

Raised in VariablePool.protocol_inputs_parser when ast.literal_eval cannot parse a declared-literal input string into the required JSON type. Literal inputs are parsed with Python's ast.literal_eval; a string that is not a valid Python literal (or not coercible to the target type) aborts parsing with this message.

Solutions

1. Quote string literals explicitly (e.g. '"some text"') or change the input type to string so literal_eval is not applied
2. Fix the literal syntax of the value (valid Python literal: numbers, True/False, lists, dicts)
3. Pre-validate the value with ast.literal_eval in a try/except before saving the workflow
4. Sanitize/resolve template placeholders before the input reaches protocol_inputs_parser

Example fix

// before
input_content = "Hello world"  # typed as number -> literal_eval fails
// after
input_content = '"Hello world"'  # or declare input type as string

import ast
try:
    ast.literal_eval(input_content)
except (ValueError, SyntaxError):
    raise ValueError(f"'{input_content}' is not a valid literal for type {json_input_type}")

def is_valid_literal(s: str) -> bool:
    import ast
    try:
        ast.literal_eval(s)
        return True
    except (ValueError, SyntaxError):
        return False

try:
    parsed = ast.literal_eval(raw)
except Exception:
    parsed = raw  # treat as plain string instead of failing

When it happens

Trigger: A workflow node input declared with a literal/json type contains content that literal_eval fails on — e.g. unquoted free text intended as a string, malformed JSON, single quotes in numeric-looking values, or template remnants like '{{var}}'.

Common situations: Users typing plain sentences into fields typed as numbers/booleans/lists; copying JSON with trailing commas; config exported from another tool with different literal syntax; unresolved mustache placeholders left in the value.

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

• ENG_PROTOCOL_VALIDATE_ERROR
• VARIABLE_POOL_SET_PARAMETER_ERROR
• VARIABLE_POOL_GET_PARAMETER_ERROR
• get variable error
• {';'.join(er_msgs)}

AI-assisted analysis of iflytek/astron-agent@5e758547a8 (2026-09-12). Data as JSON: /api/errors/91af129f3d8dba1f. Report an issue: GitHub.

Appendix: source

Thrown at core/workflow/engine/entities/variable_pool.py:380

                input_content: Any = ""
                if input_value.type == ValueType.LITERAL.value:
                    input_content = input_value.content
                    input_content_org = input_content
                    type_match = any(
                        isinstance(input_content, t) for t in python_input_type_list
                    )
                    if not type_match:
                        if json_input_type == "boolean":
                            input_content = (
                                False
                                if input_content == "false" or input_content == "False"
                                else True
                            )
                        else:
                            try:
                                input_content = ast.literal_eval(input_content)
                            except Exception:
                                raise Exception(
                                    f"Failed to convert literal value {input_key} to type {json_input_type}, literal value: {input_content_org}"
                                )
                mapping_value = {"value": input_content, "schema": input_schema}
                mapping_key = assemble_mapping_key(node_id, input_key)
                self.input_variable_mapping.update({mapping_key: mapping_value})

    def protocol_outputs_parser(self) -> None:
        """
        Parse protocol outputs and populate output variable mapping.
        """
        for node in self.nodes:
            output_nodes = node.data.outputs
            for output_node in output_nodes:
                output_key = output_node.name
                output_schema = output_node.output_schema
                output_required = output_node.required
                output_content = schema_type_default_value.get(
                    output_schema.get("type", "")

View on GitHub (pinned to 5e758547a8)