CoplayDev/unity-mcp · error · ValueError

import_settings must be a JSON object

Error message

import_settings must be a JSON object

What it means

Thrown by _normalize_import_settings() when, after optional JSON-string parsing, the value is not a dict. Import settings are a map of key/value pairs, so a non-object (array, number, string) is rejected before any field mapping occurs.

Source

Thrown at Server/src/cli/commands/texture.py:251

        return value
    if isinstance(value, (int, float)) and value in (0, 1, 0.0, 1.0):
        return bool(value)
    if isinstance(value, str):
        lowered = value.strip().lower()
        if lowered in _TRUE_STRINGS:
            return True
        if lowered in _FALSE_STRINGS:
            return False
    raise ValueError(f"{name} must be a boolean")


def _normalize_import_settings(value: Any) -> dict[str, Any]:
    if value is None:
        return {}
    if isinstance(value, str):
        value = try_parse_json(value, "import_settings")
    if not isinstance(value, dict):
        raise ValueError("import_settings must be a JSON object")

    result: dict[str, Any] = {}

    if "texture_type" in value:
        result["textureType"] = _map_enum(
            value["texture_type"], _TEXTURE_TYPES)
    if "texture_shape" in value:
        result["textureShape"] = _map_enum(
            value["texture_shape"], _TEXTURE_SHAPES)

    for snake, camel in [
        ("srgb", "sRGBTexture"),
        ("alpha_is_transparency", "alphaIsTransparency"),
        ("readable", "isReadable"),
        ("generate_mipmaps", "mipmapEnabled"),
        ("compression_crunched", "crunchedCompression"),
    ]:
        if snake in value:

View on GitHub (pinned to c21bf496bc)

Solutions

1. Wrap settings in a JSON object: `--import-settings '{"texture_type":"sprite"}'`.
2. Validate the JSON parses to a dict with `python -c "import json,sys; print(type(json.loads(sys.argv[1])))" '<value>'`.
3. Leave --import-settings off entirely to use Unity defaults.

Example fix

// before
--import-settings 'sprite'
// after
--import-settings '{"texture_type":"sprite"}'

import json
if isinstance(value, str):
    value = json.loads(value)
if not isinstance(value, dict):
    raise ValueError("import_settings must be a JSON object")

def is_import_settings_obj(v) -> bool:
    if isinstance(v, str):
        try:
            v = json.loads(v)
        except json.JSONDecodeError:
            return False
    return isinstance(v, dict)

try:
    settings = _normalize_import_settings(raw)
except ValueError as e:
    print_error(str(e)); sys.exit(1)

When it happens

Trigger: Passing --import-settings as a JSON array or scalar, e.g. `--import-settings '[]'` or `--import-settings '"sprite"'`, or calling the normalizer with a list. Also when a quoted JSON string parses to a scalar instead of an object.

Common situations: A developer passes a single import type string directly instead of an object, or misquotes the JSON so it becomes a scalar. Common when adapting an example that used a bare value.

Related errors

• set-pixels must be a JSON object
• {name} must be a boolean
• set-pixels is required
• set-pixels requires width and height when pixels are provide
• set-pixels width and height must be positive

AI-assisted analysis of CoplayDev/unity-mcp@c21bf496bc (2026-08-13). Data as JSON: /api/errors/2cd3fbecc9a123d0. Report an issue: GitHub.