create_needs_system
Generate a sim/tycoon needs engine component: a [Property] list of need definitions (name, decay rate/s, critical threshold, weight) with per-need 0..100 values that decay over Time.Delta, Satisfy(name, amount) to restore, an aggregate Happiness (weighted mean, [Sync(FromHost)] when networked), a...
This record as markdown: /tools/sbox/create-needs-system.md
What create_needs_system does on Sbox
AI agents use create_needs_system to create or update resources in Sbox, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Sbox environment.
Why create_needs_system is rated Medium
Creates and modifies game state data via component properties, events, and networked synchronization—a reversible write operation.
From the tool's definition Generate sim/tycoon needs engine component with property list, decay rates, events
Attacks that exploit this kind of access
The rule that runs create_needs_system safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Sbox, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For create_needs_system, this is the rule to start with:
create_needs_system 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 Sbox, apply this rule, and every create_needs_system call is checked against it from then on.
Questions about create_needs_system
Generate a sim/tycoon needs engine component: a [Property] list of need definitions (name, decay rate/s, critical threshold, weight) with per-need 0..100 values that decay over Time.Delta, Satisfy(name, amount) to restore, an aggregate Happiness (weighted mean, [Sync(FromHost)] when networked), and static OnNeedCritical (edge-triggered: fires once crossing below threshold, re-arms above) + OnHappinessChanged (>0.25-point moves) events. Returns {created, path, className, needs[], propertyNames[], note}. Next: trigger_hotload, get_compile_errors, then attach via targetId re-call or add_component_with_properties; drive from game code (e.g. a create_interactable that calls Satisfy). Limits: per-need values live on the simulating machine only (host) — sync per-need UI yourself via RPCs; events fire on the simulating machine only; networked default true means a no-session solo playtest won. It is categorised as a Write tool in the Sbox MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Sbox MCP server in PolicyLayer and add a rule for create_needs_system: 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 Sbox. Nothing to install.
create_needs_system 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 create_needs_system 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 create_needs_system. 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.
create_needs_system is provided by the Sbox MCP server (sbox-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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