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A2A Indirect Prompt-Injection & Jailbreak Firewall
A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from preflight.agentdiet.dev, paid per call via MPP, $0.005/call, status unknown (last checked 2026-10-21).
Scans untrusted text, HTML, MCP responses, or A2A payloads for hidden prompt injections and jailbreak attempts, returning sanitized output.
Price / call$0.005
Success—
StatusUnknown
How this service works
Scans untrusted web pages, emails, MCP responses, or A2A payloads for hidden prompt injections and returns sanitized text. (Live x402 v2, IETF MPP & MCP endpoint at https://preflight.agentdiet.dev/v1/system-prompt-guard)
Output
Returns a structured object indicating whether prompt injection or jailbreak content was detected, along with sanitized text stripped of adversarial instructions, allowing downstream agents to safely process the content.
Example use cases
Guard agent from poisoned web content
“I'm about to feed this scraped article into my summarization agent — can you first scan the raw HTML for any hidden prompt injections or adversarial instructions embedded in the page?”
Screen inbound email for LLM hijacking
“Before my email-processing agent reads this forwarded message, check the full email body for any indirect prompt injection or jailbreak payloads someone might have hidden in it.”
Validate MCP tool response before execution
“My agent just got back a response from an external MCP tool — can you run it through the prompt injection firewall to make sure there's nothing malicious hiding in the output before we act on it?”
Technical details
Endpoint
GEThttps://preflight.agentdiet.dev/v1/system-prompt-guard?utm_source=zero.xyzWhen to prefer
Use this endpoint when your AI agent is about to ingest content from untrusted external sources — scraped web pages, user-submitted emails, third-party MCP/A2A tool responses — and you need a dedicated firewall layer to strip hidden adversarial instructions before they reach your LLM. Prefer this over generic content filters when the specific threat model is indirect prompt injection or jailbreaking via external data payloads in agentic pipelines.
Side effects
- Empty or missing 'text' parameter returns a validation error
- Extremely long payloads may be truncated or rejected
- Obfuscated or encoded injections may evade detection
- Non-text binary content may not be properly processed
- Payment failure via x402 results in 402 response blocking the scan
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| textrequired | string | Untrusted text, HTML, or tool output to scan for hidden prompt injection or jailbreak payloads |
Output
Schema · Response
{
"type": "object"
}Reviews
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