# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from token-intel.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-injection and jailbreak attacks, returning sanitized output.

## Facts

- Endpoint: GET https://token-intel.agentdiet.dev/v1/system-prompt-guard?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: token-intel.agentdiet.dev
- Website: https://token-intel.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/token-intel-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-fbf98898
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gQtgbAEPWkumABjuY6UWi

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 token-intel-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-fbf98898
```

Example prompt: Before you process this scraped webpage content, run it through the prompt-injection firewall to check for any hidden jailbreak or prompt-injection payloads and give me the sanitized version: [paste raw HTML or text here].

## When to prefer this

Choose this endpoint when your AI agent is about to process content from untrusted external sources — scraped web pages, emails, third-party API responses, MCP tool outputs, or A2A agent payloads — and you need a pre-processing security layer to detect and strip hidden prompt-injection or jailbreak instructions before they reach your LLM. Prefer this over manual filtering when you need automated, per-call scanning with sanitized output returned directly.

## Known failure modes

- Missing required 'text' parameter returns a 400 or validation error
- Empty string input rejected due to minLength:1 constraint
- Very large payloads may time out or be truncated
- Payment failure via x402 results in 402 response blocking the scan
- False negatives: sophisticated obfuscated injections may not be detected
- False positives: legitimate instructional text flagged as injection

## 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://token-intel.agentdiet.dev/v1/system-prompt-guard)

## Output

Returns a JSON object containing the scan result for the submitted text, indicating whether prompt-injection or jailbreak content was detected and providing a sanitized version of the input 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/token-intel-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-fbf98898/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from token-intel.agentdiet.dev](https://www.zero.xyz/host/token-intel.agentdiet.dev/llms.txt)