# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from hn-pulse.agentdiet.dev, paid per call via MPP, $0.005/call, status unknown (last checked 2026-10-23).

Scans untrusted text, HTML, emails, MCP responses, or A2A payloads for hidden prompt injections and jailbreak attempts, returning sanitized output.

## Facts

- Endpoint: POST https://hn-pulse.agentdiet.dev/v1/indirect-injection-guard?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Provider: hn-pulse.agentdiet.dev
- Website: https://hn-pulse.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/hn-pulse-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-firewall-007f10c8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_AAJDaLg6A-AfhQ9f63Nem

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 hn-pulse-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-firewall-007f10c8 -d '<json body>'
```

Example prompt: Before you process that scraped webpage content, run it through the prompt-injection firewall to check for any hidden jailbreak instructions or adversarial payloads embedded in the text.

## When to prefer this

Choose this endpoint when your AI agent is about to process text from untrusted external sources — scraped web pages, inbound emails, third-party API/tool responses, or A2A payloads — and you need to protect the agent from indirect prompt injection or jailbreak attacks before the content reaches the LLM context. It is especially valuable in autonomous agent pipelines where content from the open web or unknown tools is fed directly into an LLM without human review.

## Known failure modes

- Empty or missing 'text' field returns a 400 validation error
- Extremely large payloads may time out or be rejected
- Legitimate content with instruction-like language (e.g. policy documents) may produce false positives
- Service unavailability returns 503
- Payment failure or insufficient balance returns 402 with x402 payment challenge

## 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://hn-pulse.agentdiet.dev/v1/indirect-injection-guard)

## Output

Returns a sanitized version of the submitted text with prompt injection and jailbreak payloads detected and flagged, along with a structured result object indicating whether malicious content was found and what was cleaned 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/hn-pulse-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-firewall-007f10c8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from hn-pulse.agentdiet.dev](https://www.zero.xyz/host/hn-pulse.agentdiet.dev/llms.txt)