# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from defi-yield.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

## Facts

- Endpoint: GET https://defi-yield.agentdiet.dev/v1/prompt-firewall?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: defi-yield.agentdiet.dev
- Website: https://defi-yield.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/defi-yield-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-8d184e61
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_pvQ5T47og_ODnN7Cr_2EU

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 defi-yield-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-8d184e61
```

Example prompt: Before you process this webpage content I scraped, scan it for any hidden prompt injections or jailbreak payloads and give me the sanitized version: '[raw HTML or text here]'

## When to prefer this

Choose this endpoint when your AI agent pipeline ingests content from untrusted external sources — web scrapes, emails, third-party API responses, or A2A/MCP payloads — and you need a lightweight, pay-per-call firewall to detect and sanitize hidden prompt injections before they reach your agent's context window. Prefer it over building custom regex filters when you need heuristic or semantic detection of jailbreak patterns at the agent infrastructure level.

## Known failure modes

- Missing required 'text' parameter returns a validation error
- Empty string input rejected due to minLength:1 constraint
- Payment not included or failed results in HTTP 402 response requiring x402 micropayment
- Very large payloads may time out or be truncated
- False negatives possible for novel or obfuscated injection techniques
- Non-text binary content may not be correctly parsed

## 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://defi-yield.agentdiet.dev/v1/prompt-firewall)

## Output

Returns a JSON object containing the scan result for the submitted text, including whether prompt injection or jailbreak content was detected and a sanitized version of the input text safe for downstream agent consumption.

## 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/defi-yield-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-8d184e61/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from defi-yield.agentdiet.dev](https://www.zero.xyz/host/defi-yield.agentdiet.dev/llms.txt)