ScrapeGraphAI/Scrapegraph-ai · error · ValueError

No state keys matched the expression.

Error message

No state keys matched the expression.
                             Expression was {expression}.
                             State contains keys: {", ".join(state.keys())}

What it means

The expression parsed successfully but evaluated to an empty result — none of the tokens in the expression match keys present in the graph state at evaluation time. The message (bug: uses literal braces, so it is not f-string interpolated) is meant to show the expression and available keys.

Source

Thrown at scrapegraphai/nodes/base_node.py:224

        def evaluate_expression(expression: str) -> List[str]:
            """Evaluate an expression with parentheses."""

            while "(" in expression:
                start = expression.rfind("(")
                end = expression.find(")", start)
                sub_exp = expression[start + 1 : end]

                sub_result = evaluate_simple_expression(sub_exp)

                expression = (
                    expression[:start] + "|".join(sub_result) + expression[end + 1 :]
                )
            return evaluate_simple_expression(expression)

        result = evaluate_expression(expression)

        if not result:
            raise ValueError(
                f"""No state keys matched the expression.
                             Expression was {expression}.
                             State contains keys: {", ".join(state.keys())}"""
            )

        final_result = []
        for key in result:
            if key not in final_result:
                final_result.append(key)

        return final_result

View on GitHub (pinned to 532dfffbf6)

Solutions

1. Print/list the graph state keys and correct the expression to reference existing ones
2. Check the node's expected state keys against the graph definition (e.g. SmartScraperGraph state)
3. Update custom nodes after upgrading the library if state keys were renamed
4. When unit-testing nodes, pass a state dict populated with all expected keys

Example fix

# before
input="my_docs & query"
# after (match actual state keys)
input="parsed_docs & user_prompt"

def keys_exist(expr: str, state: dict) -> bool:
    import re
    tokens = set(re.split(r'[&|()\s]+', expr)) - {'', '&', '|'}
    return all(t in state for t in tokens)

try:
    result = node.get_input_keys(state)
except ValueError as e:
    log state keys and expression, then correct the expression

When it happens

Trigger: Referencing a key that doesn't exist in state, e.g. input="my_docs" when state only has 'parsed_docs'; graph state schema changed after the node was written; typo in a key name.

Common situations: Upgrading ScrapeGraphAI where state key names changed; custom nodes referencing renamed state attributes; running a node standalone with a partial state dict during tests.

Related errors

• Adjacent state keys found without an operator between them.
• Invalid operator usage.
• Invalid operator placement: operators cannot be adjacent.
• Missing or unbalanced parentheses in expression.
• You need to provide key_name inside the node config

AI-assisted analysis of ScrapeGraphAI/Scrapegraph-ai@532dfffbf6 (2026-08-28). Data as JSON: /api/errors/90f81efef7d79f93. Report an issue: GitHub.