card_instance
Instance a card template into the open scene and bind data to its slots via the template's set_data(). Undoable node authoring. Slot values are strings/numbers/booleans; any texture slot (e.g. art) takes a res:// texture path. Reports which data keys bound and which had no matching slot.
This record as markdown: /tools/breakpoint-mcp/card-instance.md
What card_instance does on Breakpoint
AI agents use card_instance to create or update resources in Breakpoint, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Breakpoint environment.
| Parameter | Type | Required | Description |
|---|---|---|---|
data | object | Yes | Slot name → value; a texture slot takes a res:// path |
name | string | — | Optional node name for the instance |
parent | string | Yes | Node path to parent the instance under (in the open scene); "." for the root |
face_up | boolean | — | Show the face (default true); false shows the back on two-sided cards |
persist | boolean | — | Bake the bound slot data into the saved scene by enabling Editable Children on the instance (default false = runtime-bound only, reverts on reload) |
position | object | — | Local position of the instance |
template_path | string | Yes | Card template scene, e.g. res://ui/cards/Card.tscn |
Parameters from the server's own tool schema.
Why card_instance is rated Medium
card_instance creates and modifies scene state by instantiating a template and binding data to slots. This is a Write operation (creates/modifies data reversibly), not Execute (it doesn't run arbitrary code or shell commands — it follows a fixed card template schema). The reversibility ("Undoable") and bounded scope (slot binding via template) lower severity to medium.
From the tool's definition "Instance a card template into the open scene and bind data to its slots" — creates/modifies scene objects. "Undoable node authoring" — reversible changes. Tool name and description match typical 3D/game editor scene modification.
Attacks that exploit this kind of access
The rule that runs card_instance safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Breakpoint, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For card_instance, this is the rule to start with:
card_instance stays usable, but capped: an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Breakpoint, apply this rule, and every card_instance call is checked against it from then on.
Questions about card_instance
Instance a card template into the open scene and bind data to its slots via the template's set_data(). Undoable node authoring. Slot values are strings/numbers/booleans; any texture slot (e.g. art) takes a res:// texture path. Reports which data keys bound and which had no matching slot. It is categorised as a Write tool in the Breakpoint MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
card_instance accepts 7 parameters: data, name, parent, face_up, persist, position, template_path. Required: data, parent, template_path. The full parameter table on this page comes from the server's own tool schema.
Register the Breakpoint MCP server in PolicyLayer and add a rule for card_instance: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Breakpoint. Nothing to install.
card_instance is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the card_instance rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for card_instance. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
card_instance is provided by the Breakpoint MCP server (breakpoint-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
More on Breakpoint, and thousands of servers like it.
This server
Across the catalogue