# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from alpha-stream.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://alpha-stream.agentdiet.dev/v1/injection-guard?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: alpha-stream.agentdiet.dev
- Website: https://alpha-stream.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/alpha-stream-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-e0bc584a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gx_3mK5nAcUadoxEY0uIJ

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 alpha-stream-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-e0bc584a
```

Example prompt: Before processing that scraped webpage, run it through the injection-guard firewall to check for any hidden prompt injections or jailbreak payloads — here's the raw HTML: [paste content].

## When to prefer this

Choose this endpoint when your AI agent pipeline ingests content from untrusted external sources — scraped web pages, inbound emails, MCP tool responses, or A2A payloads — and you need a lightweight, low-cost ($0.005/call) firewall step before passing that content to an LLM. Prefer this over general content moderation APIs when the threat model is specifically adversarial prompt injection and jailbreak attempts targeting AI agents, rather than general harmful content.

## Known failure modes

- Empty or missing 'text' parameter returns a validation error
- Extremely long payloads may be truncated or rejected
- Evasive encoding techniques (e.g., Unicode obfuscation) may reduce detection accuracy
- False positives on legitimate but unusual formatting patterns
- Service unavailability returns HTTP 402 or 5xx errors

## 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://alpha-stream.agentdiet.dev/v1/injection-guard)

## Output

Returns a structured object indicating whether prompt injection or jailbreak payloads were detected in the input, along with sanitized text safe for downstream agent consumption.

## 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/alpha-stream-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-e0bc584a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from alpha-stream.agentdiet.dev](https://www.zero.xyz/host/alpha-stream.agentdiet.dev/llms.txt)