zylon-ai/private-gpt · error · ValueError

Invalid system item: {item}

Error message

Invalid system item: {item}

What it means

Raised by GET /skills/{skill_id}/versions/{version} when the skill does not exist in the collection (first guard). The route verifies the parent skill before looking up the specific version token.

Source

Thrown at private_gpt/chat/input_models.py:1262

            if value.get("type") == "text" and isinstance(value.get("text"), str):
                return [System(text=value["text"])]
            return [System.model_validate(value)]
        if isinstance(value, list):
            systems: list[System] = []
            for item in value:
                if isinstance(item, System):
                    systems.append(item)
                elif isinstance(item, TextBlock):
                    systems.append(System(text=item.text))
                elif isinstance(item, str):
                    systems.append(System(text=item))
                elif isinstance(item, dict):
                    if item.get("type") == "text" and isinstance(item.get("text"), str):
                        systems.append(System(text=item["text"]))
                    else:
                        systems.append(System.model_validate(item))
                else:
                    raise ValueError(f"Invalid system item: {item}")
            return systems or [System()]
        raise ValueError(f"Invalid system value: {value}")

    @field_validator("model", mode="before")
    @classmethod
    def normalize_model(cls, value: str | None) -> str:
        if value is None:
            return "default"
        return value

    @model_validator(mode="after")
    def extract_system_messages(self) -> "MessagesInputBase":
        """Extract role=system messages and append them to the system list."""
        system_msgs = [msg for msg in self.messages if msg.role == "system"]
        if not system_msgs:
            return self

        self.messages = [msg for msg in self.messages if msg.role != "system"]

View on GitHub (pinned to 4a030776a3)

Solutions

1. Confirm the skill exists first and handle 404 by falling back to the skill list.
2. Re-fetch the version list for the skill to obtain valid tokens.
3. Ensure the collection parameter matches the environment the token came from.

Example fix

// before
const v = await skillsApi.getVersion(id, version, col);

// after
const v = await skillsApi.getVersion(id, version, col).catch((e) => {
  if (e.status === 404) return skillsApi.listVersions(id, col).then(() => null);
  throw e;
});

const skill = await skillsApi.get(id, collection).catch(() => null);
if (!skill) throw new SkillGoneError(id);

try { return await skillsApi.getVersion(id, version, collection); }
catch (e) {
  if (e.status === 404) { const l = await skillsApi.listVersions(id, collection); return l.data[0] ?? null; }
  throw e;
}

When it happens

Trigger: Fetching a version by token for a skill id that is deleted, in another collection, or invalid.

Common situations: Version-permalink clicked after the skill was removed; cached version tokens reused across environments.

Related errors

• Unknown message role {self.role}. Expected 'system', 'user',
• Unsupported content block type: {type(block)}
• Audio size {audio_size} exceeds maximum allowed size of {set
• Invalid tool specification: {tool}
• Invalid system value: {value}

AI-assisted analysis of zylon-ai/private-gpt@4a030776a3 (2026-08-15). Data as JSON: /api/errors/8c00b7f9081c99d3. Report an issue: GitHub.