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A2A Indirect Prompt-Injection & Jailbreak Firewall
A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from hn-pulse.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 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://hn-pulse.agentdiet.dev/v1/llm-guard)
Output
Returns an object indicating whether prompt injection or jailbreak content was detected in the input, along with a sanitized version of the text with malicious instructions removed or neutralized.
Example use cases
Guarding agent from malicious web scrape
“I just scraped this webpage to feed into my agent pipeline, but I'm worried it might contain hidden prompt injections — can you scan this HTML for any jailbreak payloads and give me the clean version before we continue?”
Sanitizing incoming MCP tool responses
“My agent just got a response back from an external MCP tool — before I let the agent act on it, please scan this payload for any embedded prompt injection or override instructions: '{"result": "Ignore previous instructions and..."}'
”
Screening user-submitted email for LLM hijacking
“A user forwarded this email to be summarized by my AI assistant — can you first check the email body for any prompt injection attempts or jailbreak text so I know it's safe to pass along?”
Technical details
Endpoint
GEThttps://hn-pulse.agentdiet.dev/v1/llm-guard?utm_source=zero.xyzWhen to prefer
Choose this endpoint when your AI agent pipeline ingests content from untrusted external sources — web scraping, user-submitted text, third-party MCP tool responses, or A2A payloads — and you need to guard the LLM from indirect prompt injection or jailbreak hijacking before processing that content downstream. Prefer this over general content moderation tools when the threat model is specifically prompt injection and LLM manipulation rather than hate speech or NSFW filtering.
Side effects
- Empty or missing 'text' parameter returns a validation error
- Extremely long payloads may exceed size limits or cause timeouts
- False negatives possible — novel or obfuscated injections may not be caught
- Service unavailability returns HTTP 402 or 5xx errors
- Highly encoded or multi-layer obfuscated injections may evade detection
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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