# 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/mcp-injection-firewall?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-06d1192f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_8SEAYNUITNeoJ_VniJgz1

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-06d1192f
```

Example prompt: Before you process that scraped web page, run it through the prompt-injection firewall to check for hidden instructions or jailbreak payloads embedded in the HTML — here's the raw content: [paste text].

## When to prefer this

Choose this endpoint when your AI agent or pipeline processes content from untrusted external sources — scraped web pages, inbound emails, third-party MCP tool responses, or A2A agent payloads — and you need a real-time guard against indirect prompt injection and jailbreak attacks before feeding that content to an LLM. It is especially appropriate for agentic architectures where tool outputs are automatically processed without human review.

## Known failure modes

- Empty or missing 'text' parameter returns a validation error
- Extremely large payloads may be rejected or truncated
- Payment not fulfilled (HTTP 402) blocks the scan from completing
- Network timeout if the firewall service is under load
- False negatives possible for novel or obfuscated injection techniques

## 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/mcp-injection-firewall)

## Output

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

## 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-06d1192f/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)