# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from polymarket-odds.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://polymarket-odds.agentdiet.dev/v1/guard?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: polymarket-odds.agentdiet.dev
- Website: https://polymarket-odds.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/polymarket-odds-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-8ce8b4f9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4cfQAJDMuypWLVyGCI2s5

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 polymarket-odds-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-8ce8b4f9
```

Example prompt: Before you process this scraped webpage content, run it through the prompt-injection firewall to check for any hidden instructions or jailbreak attempts trying to hijack you: [paste of HTML/text]

## When to prefer this

Use this endpoint whenever an AI agent is about to process content from untrusted external sources — web scrapes, emails, third-party API responses, MCP tool outputs, or user-submitted text — and needs a security gate before acting on that content. Prefer this over manual filtering when the content could contain adversarially crafted prompt injections designed to hijack the agent's behavior. Especially valuable in agentic pipelines where intermediate tool outputs feed directly back into LLM context.

## Known failure modes

- Missing required 'text' parameter returns a 400 Bad Request error
- Empty string input (minLength:1 violated) returns validation error
- Payment not included or insufficient triggers HTTP 402 payment required
- Very long payloads may hit timeout or size limits
- Novel obfuscated injection techniques may not be detected (false negatives)
- Non-English injections may have reduced detection accuracy

## 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://polymarket-odds.agentdiet.dev/v1/guard)

## Output

Returns a JSON object indicating whether prompt injection or jailbreak content was detected, along with sanitized version of the input text stripped of malicious instruction payloads, enabling safe downstream processing by AI agents.

## 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/polymarket-odds-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-8ce8b4f9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from polymarket-odds.agentdiet.dev](https://www.zero.xyz/host/polymarket-odds.agentdiet.dev/llms.txt)