# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from onchain-risk.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://onchain-risk.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: onchain-risk.agentdiet.dev
- Website: https://onchain-risk.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/onchain-risk-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-c1a219e5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_YrB7TYKPafCotIQSrZ8cn

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 onchain-risk-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-c1a219e5
```

Example prompt: Before you process the HTML scraped from that external site, run it through the prompt-injection firewall first and give me the sanitized version — I want to make sure there are no hidden jailbreak instructions embedded in it.

## When to prefer this

Choose this endpoint when your AI agent pipeline ingests content from untrusted external sources — scraped web pages, user emails, third-party API responses, MCP tool outputs, or A2A payloads — and you need a dedicated firewall check before passing that content to your LLM. Prefer this over generic content filters when you specifically need protection against indirect prompt injection and jailbreak patterns in agentic workflows, especially those using MCP or A2A protocols.

## Known failure modes

- Empty or missing 'text' parameter returns a validation error
- Extremely large payloads may exceed processing limits or timeout
- Obfuscated or novel injection techniques may not be detected, producing false negatives
- Payment failure via x402 results in HTTP 402 and no scan result
- Service unavailability returns a 5xx error with no sanitized output

## 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://onchain-risk.agentdiet.dev/v1/injection-guard)

## Output

Returns a structured object indicating whether prompt injection or jailbreak content was 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/onchain-risk-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-c1a219e5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from onchain-risk.agentdiet.dev](https://www.zero.xyz/host/onchain-risk.agentdiet.dev/llms.txt)