# 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 content.

## Facts

- Endpoint: GET https://alpha-stream.agentdiet.dev/v1/injection-firewall?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-ee7d34d8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_sJ9QcIJfUgicdfRfMiYif

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-ee7d34d8
```

Example prompt: Before you process this scraped webpage content, run it through the prompt-injection firewall to check for any hidden jailbreak instructions or adversarial prompts embedded in the text: [paste content here].

## When to prefer this

Choose this endpoint when your AI agent needs to process content from untrusted external sources — web pages, emails, MCP tool responses, or A2A payloads — and you need a dedicated firewall layer to detect and strip hidden prompt injections or jailbreak attempts before they reach your LLM. Prefer this over generic content filters when the threat model specifically involves adversarial LLM manipulation via indirect injection, or when operating in agentic pipelines where external tool outputs feed back into model context.

## Known failure modes

- Empty or missing 'text' parameter returns a 400 validation error
- Very long inputs may exceed character limits or time out
- Novel or obfuscated injection techniques may evade detection (false negatives)
- Legitimate instructional text may be incorrectly flagged as injection (false positives)
- Service unavailability returns 5xx errors
- Payment not completed (HTTP 402) if x402 payment header is missing or invalid

## 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-firewall)

## Output

Returns a sanitized version of the input text with detected prompt injection or jailbreak payloads removed or flagged, along with metadata about what was found. The response is a JSON object indicating whether threats were detected and providing clean text safe for downstream LLM 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-ee7d34d8/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)