# 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 2026-10-23).

Scans untrusted text, HTML, emails, MCP responses, or A2A payloads for hidden prompt injections and jailbreak attempts, returning sanitized output.

## Facts

- Endpoint: POST https://polymarket-odds.agentdiet.dev/v1/prompt-shield?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-23
- 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-fa9de985
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_6CPQ_u9UNWqlB27P7nVX5

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-fa9de985 -d '<json body>'
```

Example prompt: Before you process that scraped webpage content, can you run it through the prompt-injection firewall to check for any hidden jailbreak instructions or embedded prompt attacks and give me the sanitized version?

## When to prefer this

Choose this endpoint when your AI agent pipeline ingests content from untrusted external sources — web pages, emails, third-party API responses, MCP tool outputs, or A2A messages — and you need a dedicated firewall step to strip hidden prompt injections before the content reaches your LLM. Prefer this over generic content filtering when you specifically need protection against adversarial AI manipulation rather than general moderation.

## Known failure modes

- Empty or missing 'text' field returns a validation error
- Extremely large payloads may exceed size limits and return an error
- Service unavailability returns a 503 or 402 payment-required response
- Ambiguous or novel injection techniques may not be detected with certainty
- Rate limiting may apply if called in rapid succession without idempotency key

## 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/prompt-shield)

## Output

Returns a JSON object containing the sanitized version of the input text with prompt injection and jailbreak payloads removed or flagged, along with detection signals indicating whether threats were found.

## 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-fa9de985/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)