upload_image

SERVERA3plus SOURCEa3plus-mcp

Medium RISK CLASS

Category Write

Parameters 31 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/a3plus-mcp/upload-image.md

WHAT IT DOES

What upload_image does on A3plus

AI agents use upload_image to create or update resources in A3plus, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your A3plus environment.

Parameter	Type	Required	Description
`url`	string	—	Public source URL to fetch server-side. Mutually exclusive with base64.
`base64`	string	—	Base64-encoded image bytes (data: URI prefix tolerated). Mutually exclusive with url.
`siteId`	string	Yes	The A3Plus site ID this image belongs to.

Parameters from the server's own tool schema.

RISK

Why upload_image is rated Medium

An AI agent can call upload_image faster than any human can review: one bad instruction and it creates or modifies resources in A3plus by the hundred, each call as confident as the last.

Risk signalsAccepts URL/endpoint input (url)

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs upload_image safely

PolicyLayer is an MCP gateway: it sits between your AI agents and A3plus, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For upload_image, this is the rule to start with:

upload_image Rate-limited

upload_image 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": {
    "upload_image": {
      "limits": [
        {
          "counter": "upload_image_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect A3plus, apply this rule, and every upload_image call is checked against it from then on.

FAQ

Questions about upload_image

What does the upload_image tool do? +

Upload an image to A3Plus CDN (Cloudflare R2) and get back a permanent URL. Use this when the image source is WAF-protected (server-side fetch returns 403) or when you have the image bytes locally. Pass EITHER base64 (raw base64 or data: URI) OR url (server fetches it). The returned image.url can be used as featuredImageUrl, in inlineImages, or directly in markdown — create/update article will not refetch it. Allowed formats: jpeg, png, webp, gif, avif (detected from magic bytes). Max 10 MB. It is categorised as a Write tool in the A3plus MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

What parameters does upload_image accept? +

upload_image accepts 3 parameters: url, base64, siteId. Required: siteId. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on upload_image? +

Register the A3plus MCP server in PolicyLayer and add a rule for upload_image: 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 A3plus. Nothing to install.

What risk level is upload_image? +

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

Can I rate-limit upload_image? +

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

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

upload_image is provided by the A3plus MCP server (a3plus-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

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