ansible/ansible · error · TypeError

Key of type {type(k).__name__!r} is not JSON serializable by

Error message

Key of type {type(k).__name__!r} is not JSON serializable by the {cls.profile_name!r} profile.

What it means

Error "Key of type {type(k).__name__!r} is not JSON serializable by the {cls.profile_name!r} profile." thrown in ansible/ansible.

Source

Thrown at lib/ansible/module_utils/_internal/_json/_profiles/__init__.py:212

    @classmethod
    def post_init(cls) -> None:
        pass

    @classmethod
    def maybe_wrap(cls, o: t.Any) -> t.Any:
        if type(o) in cls._unwrapped_json_types:
            return o

        return _WrappedValue(o)

    @classmethod
    def handle_key(cls, k: t.Any) -> t.Any:
        """Validation/conversion hook before a dict key is serialized. The default implementation only accepts str-typed keys."""
        # NOTE: Since JSON requires string keys, there is no support for preserving tags on dictionary keys during serialization.

        if not isinstance(k, str):  # DTFIX-FUTURE: optimize this to use all known str-derived types in type map / allowed types
            raise TypeError(f'Key of type {type(k).__name__!r} is not JSON serializable by the {cls.profile_name!r} profile.')

        return k

    @classmethod
    def _handle_key_str_fallback(cls, k: t.Any) -> t.Any:
        """Legacy implementations should use this key handler for backward compatibility with stdlib JSON key conversion quirks."""
        # DTFIX-FUTURE: optimized exact-type table lookup first

        if isinstance(k, str):
            return k

        if k is None or isinstance(k, (int, float)):
            return json.dumps(k)

        raise TypeError(f'Key of type {type(k).__name__!r} is not JSON serializable by the {cls.profile_name!r} profile.')

    @classmethod
    def default(cls, o: t.Any) -> t.Any:

View on GitHub (pinned to 9cf16a4aca)

Solutions

1. Use string keys in dictionaries that will be JSON serialized.
2. Convert non-string keys to strings before returning.

When it happens

Trigger: Thrown at lib/ansible/module_utils/_internal/_json/_profiles/__init__.py:212 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of ansible/ansible@9cf16a4aca (2026-08-15). Data as JSON: /api/errors/72dc82207a301edd. Report an issue: GitHub.