# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from x402-audit.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 injection and jailbreak attempts, returning sanitized output.

## Facts

- Endpoint: GET https://x402-audit.agentdiet.dev/v1/injection-firewall?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: x402-audit.agentdiet.dev
- Website: https://x402-audit.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/x402-audit-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-c36e64c7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_otJii3fqSy-8_PPx8x1t7

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability x402-audit-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-c36e64c7
```

Example prompt: Before you process that scraped web page, run it through the prompt injection firewall first — check it for any hidden jailbreak instructions or adversarial text embedded in the HTML and give me the sanitized version.

## When to prefer this

Choose this endpoint when your AI agent pipeline ingests content from untrusted external sources — web pages, emails, third-party APIs, MCP tool responses, or A2A payloads — and you need to screen that content for hidden adversarial instructions before your LLM processes it. It is especially valuable in agentic workflows where indirect prompt injection is a real attack vector. Prefer this over generic content filters when you specifically need prompt-injection and jailbreak detection tuned for AI agent contexts.

## Known failure modes

- Empty or missing 'text' parameter returns a 400 validation error
- Very large payloads may exceed input size limits and return an error
- False negatives are possible if injections use novel obfuscation techniques
- Rate limits or payment failures (x402) may result in 402 or 429 responses
- Highly encoded or binary content may not be fully analyzed

## 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://x402-audit.agentdiet.dev/v1/injection-firewall)

## Output

Returns a JSON object indicating whether a prompt injection or jailbreak payload was detected in the input text, along with a sanitized version of the text with any malicious instructions removed or flagged.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "text"
 ],
 "properties": {
  "text": {
   "type": "string",
   "minLength": 1,
   "description": "Untrusted text, HTML, or tool output to scan for hidden prompt injection or jailbreak payloads"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-audit-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-c36e64c7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-audit.agentdiet.dev](https://www.zero.xyz/host/x402-audit.agentdiet.dev/llms.txt)