# 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 injection and jailbreak attempts, returning sanitized output.

## Facts

- Endpoint: GET https://whale-momentum.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: 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-6daf607b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VwDdoGg61qhIraSHkyhud

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-6daf607b
```

Example prompt: Before you process that scraped web page, run it through the prompt injection firewall first — I want to make sure there are no hidden instructions or jailbreak payloads embedded in the HTML before you act on it.

## When to prefer this

Use this endpoint whenever an AI agent is about to process untrusted external content — scraped HTML, third-party API responses, user-submitted text, emails, or MCP/A2A payloads — before acting on it. It is especially valuable in agentic pipelines where content from the open web or untrusted tools could contain adversarial instructions designed to hijack agent behavior. Prefer this over manual filtering when you need a dedicated, specialized scanner rather than general-purpose text processing.

## Known failure modes

- Empty or missing 'text' parameter returns validation error
- Text that is too large may hit payload limits or timeout
- False negatives: sophisticated obfuscated injections may not be caught
- False positives: legitimate instructional text may be flagged as injection
- Service unavailable or 402 payment required if credits are exhausted

## 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-firewall)

## Output

Returns a structured object indicating whether prompt injection or jailbreak content was detected, along with sanitized text stripped of adversarial instructions, allowing the agent to safely use the cleaned output downstream.

## 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-6daf607b/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)