# 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/guard?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-87ce958b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_aLyk-X2NZbP-y4cHp2dOE

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-87ce958b
```

Example prompt: Before you process that web page I scraped, run the raw HTML through the prompt injection firewall and give me the sanitized version — I don't want any hidden instructions sneaking into your context.

## When to prefer this

Choose this endpoint when your AI agent pipeline ingests untrusted third-party content — web pages, emails, tool responses, or A2A payloads — and you need to strip hidden prompt injection or jailbreak instructions before those inputs reach your LLM context. It is particularly suited for agentic workflows where indirect prompt injection is a realistic threat vector, such as browsing-enabled agents, email-processing agents, or multi-agent systems consuming external MCP tool outputs.

## Known failure modes

- Empty or missing 'text' parameter returns a validation error
- Extremely large payloads may exceed size limits and return a 400 or 413 error
- Service unavailability or payment failure (HTTP 402) if USDC balance is insufficient
- Ambiguous or highly obfuscated injections may be missed (false negatives)
- Non-text binary content passed as text may produce unreliable scan results

## 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/guard)

## Output

Returns a JSON object containing the scan result, including whether prompt injection or jailbreak content was detected and a sanitized version of the input text with malicious instructions removed or neutralized.

## 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-87ce958b/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)