# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from whale-momentum.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://whale-momentum.agentdiet.dev/v1/prompt-injection-shield?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: whale-momentum.agentdiet.dev
- Website: https://whale-momentum.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/whale-momentum-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-f9721dfc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mwFg6bfB1viI3UpzesgGh

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 whale-momentum-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-f9721dfc
```

Example prompt: Before you process that scraped web page, run it through the prompt-injection firewall to check for any hidden adversarial instructions or jailbreak payloads embedded in the HTML, then 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, tool outputs, or third-party A2A/MCP payloads — before passing that content to an LLM for reasoning or action. It is specifically designed for agent-to-agent and MCP threat surfaces, unlike generic content moderation APIs that focus on human-generated harmful content rather than adversarial LLM manipulation techniques.

## Known failure modes

- Empty or missing 'text' parameter returns a validation error
- Extremely large payloads may time out or be truncated
- Obfuscated injections using novel encoding techniques may evade detection
- Non-UTF8 or binary content may cause parsing errors
- HTTP 402 payment required if funds not provided via x402 protocol

## 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://whale-momentum.agentdiet.dev/v1/prompt-injection-shield)

## Output

Returns a JSON object containing the scan result, including whether a prompt injection or jailbreak payload was detected, and the sanitized version of the input text with adversarial 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/whale-momentum-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-f9721dfc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from whale-momentum.agentdiet.dev](https://www.zero.xyz/host/whale-momentum.agentdiet.dev/llms.txt)