juno_config_apply · Junobuild MCP: Risk & Policy

WHAT IT DOES

What juno_config_apply does on Junobuild

AI agents use juno_config_apply to create or update resources in Junobuild — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Junobuild environment.

WHY IT NEEDS A POLICY

Why juno_config_apply needs a policy

This tool modifies configuration settings on a deployed satellite (cloud hosting platform). It updates multiple subsystems: storage headers, datastore rules, authentication config, and collection definitions. These are reversible changes (configuration can be reverted), not irreversible deletions.

From the tool's definition Apply the current juno.config file to your satellite. This is required after modifying settings like storage headers, datastore rules, authentication config, or collection definitions.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

juno_config_apply Rate-limited

juno_config_apply 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "juno_config_apply": {
      "limits": [
        {
          "counter": "juno_config_apply_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Junobuild, so you can run agents against it safely.

FAQ

Questions about juno_config_apply

What does the juno_config_apply tool do? +

Apply the current juno.config file to your satellite. This is required after modifying settings like storage headers, datastore rules, authentication config, or collection definitions. It is categorised as a Write tool in the Junobuild MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on juno_config_apply? +

Register the Junobuild MCP server in PolicyLayer and add a rule for juno_config_apply: 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 Junobuild. Nothing to install.

What risk level is juno_config_apply? +

juno_config_apply is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit juno_config_apply? +

Yes. Add a rate_limit block to the juno_config_apply 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 juno_config_apply completely? +

Set action: deny in the PolicyLayer policy for juno_config_apply. 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 juno_config_apply? +

juno_config_apply is provided by the Junobuild MCP server (junobuild-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.