OpenBB-finance/OpenBB · error · ValueError

Prompt name '{v}' should be a valid identifier

Error message

Prompt name '{v}' should be a valid identifier

What it means

Pydantic validation error on PromptConfigModel.name: the provided name (after strip) does not match ^[a-zA-Z_][a-zA-Z0-9_]*$, i.e. it is not identifier-like. Prompt names become tool/resource identifiers on the MCP server, so dashes, spaces, dots, and leading digits are rejected.

Source

Thrown at openbb_platform/extensions/mcp_server/openbb_mcp_server/models/mcp_config.py:127

        open_braces = v.count("{")
        close_braces = v.count("}")
        if open_braces != close_braces:
            raise ValueError(
                f"Unmatched braces in prompt content: {open_braces} opening, {close_braces} closing"
            )

        return v

    @field_validator("name")
    @classmethod
    def validate_name(cls, v: str | None) -> str | None:
        """Validate prompt name if provided."""
        if v is not None:
            if not v.strip():
                raise ValueError("Prompt name cannot be empty string")
            # Check for valid identifier-like name
            if not re.match(r"^[a-zA-Z_][a-zA-Z0-9_]*$", v.strip()):
                raise ValueError(f"Prompt name '{v}' should be a valid identifier")
        return v

    @field_validator("tags")
    @classmethod
    def validate_tags(cls, v: list[str]) -> list[str]:
        """Validate tags are non-empty strings."""
        validated_tags = []
        for tag in v:
            if not isinstance(tag, str):
                raise ValueError(f"Tag must be a string, got {type(tag)}")
            if not tag.strip():
                raise ValueError("Tag cannot be empty string")
            validated_tags.append(tag.strip())
        return validated_tags


class MCPConfigModel(BaseModel):
    """Model for validating the main MCP configuration structure."""

View on GitHub (pinned to 3e071fcc2c)

Solutions

1. Use snake_case identifiers: 'my-prompt' → 'my_prompt'.
2. Start with a letter or underscore; strip file extensions and punctuation.
3. Leave name unset to let the server auto-generate a valid one.

Example fix

# before
prompts:
  - name: daily-report
    content: "..."

# after
prompts:
  - name: daily_report
    content: "..."

import re

def prompt_name_or_none(name: str | None) -> str | None:
    if name is None:
        return None
    n = re.sub(r"[^a-zA-Z0-9_]+", "_", name.strip()).strip("_")
    n = f"_{n}" if n[:1].isdigit() else n
    assert re.match(r"^[a-zA-Z_][a-zA-Z0-9_]*$", n), f"unusable name {name!r}"
    return n

def is_identifier_like(name: str | None) -> bool:
    return name is None or (bool(name.strip()) and bool(re.match(r"^[a-zA-Z_][a-zA-Z0-9_]*$", name.strip())))

When it happens

Trigger: Naming a prompt 'my-prompt', '1_greet', 'greet.me', or 'daily report' in the config; deriving names from human titles or file names with hyphens; non-ASCII names.

Common situations: Slugs with hyphens copied from URLs; prompts generated from markdown headings; names mirroring filenames like 'my-prompt.md'.

Related errors

• Prompt name cannot be empty string
• Argument name '{v}' must be a valid Python identifier
• Prompt content cannot be empty
• Unmatched braces in prompt content: {open_braces} opening, {
• Argument name cannot be empty

AI-assisted analysis of OpenBB-finance/OpenBB@3e071fcc2c (2026-08-14). Data as JSON: /api/errors/167661425ce9553d. Report an issue: GitHub.