# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from mesh.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 text

## Facts

- Endpoint: POST https://mesh.agentdiet.dev/v1/mcp-security?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Provider: mesh.agentdiet.dev
- Website: https://mesh.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/mesh-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-firewall-e3eac922
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oiCadXqSeOvT8BXOFRFlw

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 mesh-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-firewall-e3eac922 -d '<json body>'
```

Example prompt: Before you summarize that web page content, run it through the prompt injection firewall first — I want to make sure there aren't any hidden instructions trying to hijack you embedded in the HTML.

## 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 payloads — and you need a dedicated security layer to detect and strip hidden prompt injection or jailbreak instructions before they reach your LLM. Prefer this over generic content filters when you specifically need protection against adversarial AI-targeting attacks rather than spam or inappropriate content.

## Known failure modes

- Empty or missing 'text' field returns a validation error
- Extremely large payloads may be rejected or truncated
- Payment failure (HTTP 402) if x402 USDC micropayment is not provided or fails
- False negatives are possible — novel or highly obfuscated injections may not be detected
- Network timeout on long HTML documents
- Non-idempotent retry behavior if Idempotency-Key header is omitted across retries

## 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://mesh.agentdiet.dev/v1/mcp-security)

## Output

Returns an object indicating whether prompt injection or jailbreak content was detected in the submitted text, along with sanitized/cleaned text with malicious instructions removed, allowing the agent to safely process the content downstream.

## 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/mesh-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-firewall-e3eac922/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mesh.agentdiet.dev](https://www.zero.xyz/host/mesh.agentdiet.dev/llms.txt)