AI agents invoke blend_images to trigger actions in Midjourney MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
Blending images is an external execution operation that calls a third-party API to process and combine images. It is not a simple read, nor does it delete data or move money. It creates a new derived image, but the primary action is executing an external transformation pipeline rather than a simple write/upload.
From the tool's definition 'Blend multiple images together' — triggers an external image processing operation via the GPTNB API, producing a new artifact by executing a transformation on provided inputs.
Documented attack patterns abuse exactly the kind of access blend_images gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Midjourney MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for blend_images:
{
"version": "1",
"default": "deny",
"tools": {
"blend_images": {
"limits": [
{
"counter": "blend_images_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}blend_images stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
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Blend multiple images together. It is categorised as a Execute tool in the Midjourney MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Midjourney MCP Server MCP server in PolicyLayer and add a rule for blend_images: 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 Midjourney MCP Server. Nothing to install.
blend_images is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the blend_images 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 blend_images. 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.
blend_images is provided by the Midjourney MCP Server MCP server (z23cc/midjourney-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Midjourney MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
7 Midjourney MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.