langflow-ai/langflow · error · HTTPException

Template not found

Error message

Template not found

What it means

Raised by the template-create helper when get_template_by_id cannot find a starter-project template with the given template_id. Templates come from the bundled starter_projects collection; the id must match the 'id' field inside that JSON exactly. 404.

Source

Thrown at src/backend/base/langflow/agentic/utils/template_create.py:48

    template_id: str,
    target_folder_id: UUID | None = None,
) -> dict[str, Any]:
    """Create a new flow from a starter template and return its id and UI link.

    Args:
        session: Active async DB session.
        user_id: The owner user id for the new flow.
        template_id: The string id field inside the starter template JSON.
        target_folder_id: Optional folder id to place the flow. If not provided,
            the user's default folder will be used.

    Returns:
        Dict with keys: {"id": str, "link": str}
    """
    # 1) Load template JSON from starter_projects
    template = get_template_by_id(template_id=template_id, fields=None)
    if not template:
        raise HTTPException(status_code=404, detail="Template not found")

    # 2) Resolve target folder
    if target_folder_id:
        folder = await session.get(Folder, target_folder_id)
        if not folder or folder.user_id != user_id:
            raise HTTPException(status_code=400, detail="Invalid target folder")
        folder_id = folder.id
    else:
        default_folder = await get_or_create_default_folder(session, user_id)
        folder_id = default_folder.id

    # 3) Build FlowCreate from template fields (ignore unknowns)
    new_flow = FlowCreate(
        name=template.get("name"),
        description=template.get("description"),
        icon=template.get("icon"),
        icon_bg_color=template.get("icon_bg_color"),
        gradient=template.get("gradient"),

View on GitHub (pinned to 976ec789d2)

Solutions

1. List available templates (GET /api/v1/starter-projects/ or the equivalent) and use an id from the response.
2. Check the template_id spelling and case against the installed starter_projects JSON.
3. After upgrading Langflow, re-verify template ids — they are version-dependent.

Example fix

# before
create_flow_from_template(template_id="basic_prompt")

# after
templates = client.get("/api/v1/starter-projects/").json()
create_flow_from_template(template_id=templates[0]["id"])

templates = client.get("/api/v1/starter-projects/").json()
valid_ids = {t["id"] for t in (templates if isinstance(templates, list) else templates.get("templates", []))}
assert template_id in valid_ids, f"unknown template {template_id!r}; valid: {sorted(valid_ids)[:10]}..."

try:
    create_flow_from_template(template_id=tid)
except HTTPError as e:
    if e.response.status_code == 404:
        tid = pick_from_list_response()  # re-resolve against installed set
        create_flow_from_template(template_id=tid)
    else:
        raise

When it happens

Trigger: POSTing the create-from-template endpoint/MCP tool with a template_id that is not in starter_projects — typos, a template removed in the current version, or an id from the marketplace that is not bundled locally.

Common situations: Langflow upgrades renaming/removing starter templates; ids copied from online docs that differ from the installed version's set; case sensitivity ('basic-prompt' vs 'Basic-Prompt').

Related errors

• Failed to load file (HTTP ${status})
• reload-in-progress
• An error occurred while uploading the file
• Flow not found
• Build job not found

AI-assisted analysis of langflow-ai/langflow@976ec789d2 (2026-08-14). Data as JSON: /api/errors/1ff2d0b23ab4e926. Report an issue: GitHub.