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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, emails, MCP responses, or A2A payloads for hidden prompt injections and jailbreak attempts, returning sanitized content.
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/llm-guard)
Output
Returns a JSON object indicating whether the input text contains prompt injection or jailbreak content, along with a sanitized version of the text with malicious instructions removed or flagged.
Example use cases
Sanitizing scraped web content for agent pipeline
“I'm about to feed this scraped article HTML into my summarizer agent — can you first scan it for any hidden prompt injections or jailbreak payloads and return the clean text only?”
Checking suspicious email before LLM processing
“This email looks a bit off and I want to feed it to my AI assistant — run it through the prompt injection firewall first and tell me if there are any adversarial instructions hidden in the body.”
Validating MCP tool response before agent action
“My agent just got back a response from an external MCP tool — before it acts on that output, scan it for indirect prompt injection attempts so we don't get hijacked.”
Technical details
Endpoint
GEThttps://preflight.agentdiet.dev/v1/llm-guard?utm_source=zero.xyzWhen to prefer
Choose this endpoint when your AI agent pipeline ingests untrusted external content — scraped web pages, emails, MCP/A2A tool responses, or user-submitted text — and you need to guard against indirect prompt injection before the content reaches your LLM. It is especially valuable in autonomous multi-agent workflows where a compromised upstream tool could hijack downstream agent behavior.
Side effects
- Empty or missing 'text' parameter returns a 400 validation error
- Very long payloads may be truncated or rejected
- Subtle or novel injection techniques may evade detection
- Non-text binary content may not be scannable
- Payment failure (HTTP 402) if USDC balance is insufficient for the $0.005 per-call fee
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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