canvas_list

List all active canvas sessions for the current task

SERVERCoWork OS SOURCECoWork-OS/CoWork-OS

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/cowork-os/canvas-list.md

WHAT IT DOES

What canvas_list does on CoWork OS

AI agents call canvas_list to retrieve information from CoWork OS without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why canvas_list is rated Low

This tool queries and returns information about active canvas sessions. It performs a read-only operation that retrieves data without creating, modifying, deleting, or executing any actions. The verb 'list' is a classic read operation. The potential blast radius if misused is minimal, as an agent cannot cause damage by listing sessions.

From the tool's definition Tool name 'canvas_list' and description 'List all active canvas sessions for the current task' indicate a retrieval operation with no side effects.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs canvas_list safely

PolicyLayer is an MCP gateway: it sits between your AI agents and CoWork OS, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For canvas_list, this is the rule to start with:

canvas_list Allowed

canvas_list is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "canvas_list": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect CoWork OS, apply this rule, and every canvas_list call is checked against it from then on.

FAQ

Questions about canvas_list

What does the canvas_list tool do? +

List all active canvas sessions for the current task. It is categorised as a Read tool in the CoWork OS MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on canvas_list? +

Register the CoWork OS MCP server in PolicyLayer and add a rule for canvas_list: 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 CoWork OS. Nothing to install.

What risk level is canvas_list? +

canvas_list is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit canvas_list? +

Yes. Add a rate_limit block to the canvas_list 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.

How do I block canvas_list completely? +

Set action: deny in the PolicyLayer policy for canvas_list. 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.

What MCP server provides canvas_list? +

canvas_list is provided by the CoWork OS MCP server (CoWork-OS/CoWork-OS). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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