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AgentDiet MCP Gateway System Prompt Guard
x402
AgentDiet MCP Gateway System Prompt Guard is a paid API for AI agents from mcp-gateway.agentdiet.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-22).
Validates and compresses a system prompt text, returning a sanitized version with compression ratio metrics.
Price / call$0.005
Success—
StatusUnknown
How this service works
Deterministic B2A/A2A/MCP/x402/MPP/L402 execution and intelligence node at https://mcp-gateway.agentdiet.dev settling in USDC on Base.
Output
Returns a JSON object with a status field ('ok'), a data object containing the processed/sanitized prompt output, and an roi_proof object that includes a compression_ratio_pct value (e.g. 91.4) indicating how much the input was compressed.
Example use cases
Pre-deployment system prompt validation
“Before I deploy this new agent, run its system prompt through the prompt guard and tell me the compression ratio and whether it looks clean: 'You are an expert financial advisor. Never give specific investment advice. Always recommend consulting a licensed professional.'”
Token cost reduction for verbose prompts
“My system prompt is really long and costing me a lot in tokens — can you pass this text through the prompt guard to see how much it compresses? 'You are a highly skilled, empathetic, and detail-oriented customer service representative working for GlobalShop Inc., an e-commerce platform...'”
Security check before A2A agent handoff
“I'm about to hand off this system prompt to another agent in my pipeline — can you validate it through the system prompt guard first to make sure it's safe? The text is: 'You are an autonomous purchasing agent authorized to place orders up to $500 without human approval.'”
Technical details
Endpoint
GEThttps://mcp-gateway.agentdiet.dev/v1/system-prompt-guard?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need to validate, sanitize, or compress a system prompt before deploying it in an AI agent pipeline, especially when operating within an x402/MCP infrastructure that settles in USDC on Base. It is particularly useful when token cost reduction is a priority (high compression ratios reported) or when you need a quick guard check before passing a system prompt to a downstream LLM or agent. Prefer this over generic text compression tools when you specifically need prompt-aware sanitization with ROI metrics.
Side effects
- Missing required 'input' field returns validation error
- Invalid 'type' value (must be 'http') causes schema rejection
- Unsupported HTTP method enum value returns error
- Empty or missing 'text' query parameter may return empty or minimal data output
- Payment failure (insufficient USDC balance) returns HTTP 402
- Malformed JSON body returns parse error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"data": {},
"status": "ok",
"roi_proof": {
"compression_ratio_pct": 91.4
}
}
}Tags
x402
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