assets_put · Run402 MCP: Risk & Policy

WHAT IT DOES

What assets_put does on Run402

AI agents use assets_put to create or update resources in Run402 — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Run402 environment.

WHY IT NEEDS A POLICY

Why assets_put needs a policy

This tool creates and modifies data in project storage (S3), making it a Write operation. Severity is high because: (1) it can upload files up to 5 TiB, enabling large-scale data injection; (2) uploading malicious content (binaries, scripts) to public CDN URLs could compromise downstream users; (3) in context of an 'Autonomous infra for Coding Agents paid by X402', an agent could upload unauthorized data to storage,…

From the tool's definition Upload a blob (file or inline content) to project storage via direct-to-S3. Accepts local_path (any size up to 5 TiB) or content (≤ 1 MB inline). Public blobs get a CDN URL; private blobs require authenticated reads.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

assets_put Rate-limited

assets_put 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": {
    "assets_put": {
      "limits": [
        {
          "counter": "assets_put_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 Run402, so you can run agents against it safely.

FAQ

Questions about assets_put

What does the assets_put tool do? +

Upload a blob (file or inline content) to project storage via direct-to-S3. Accepts local_path (any size up to 5 TiB) or content (≤ 1 MB inline). Public blobs get a CDN URL; private blobs require authenticated reads. Use. It is categorised as a Write tool in the Run402 MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on assets_put? +

Register the Run402 MCP server in PolicyLayer and add a rule for assets_put: 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 Run402. Nothing to install.

What risk level is assets_put? +

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

Can I rate-limit assets_put? +

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

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

assets_put is provided by the Run402 MCP server (kychee-com/run402). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.