# AgentDiet Prompt Shield

> AgentDiet Prompt Shield is a paid API for AI agents from agentdiet.dev, paid per call via x402 or MPP, $0.005/call, status unknown (last checked 2026-10-20).

Scans untrusted text (web pages, emails, MCP responses, A2A payloads) for hidden prompt injections and jailbreak attempts, returning sanitized content.

## Facts

- Endpoint: GET https://agentdiet.dev/v1/prompt-shield?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402, MPP
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentdiet-prompt-shield-732fae9f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mY1ImtqpeF2Rem8pTcwEF

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 agentdiet-prompt-shield-732fae9f
```

Example prompt: Before you process that webpage I just scraped, run it through the prompt shield first — check the text for any hidden prompt injections or jailbreak instructions that could hijack you.

## When to prefer this

Use this endpoint when your agent pipeline ingests content from untrusted external sources — scraped web pages, user-submitted emails, third-party MCP responses, or A2A payloads — and you need a dedicated firewall layer to detect and strip hidden prompt injections before that content reaches your LLM. Prefer this over generic content filtering when the threat model specifically involves adversarial AI manipulation rather than general content moderation.

## Known failure modes

- Empty or missing 'text' query parameter returns an error
- Extremely large payloads may be rejected or truncated
- Sophisticated obfuscated injections may evade detection
- Non-text or binary content passed as text may cause unexpected behavior
- Network timeout on very large inputs

## 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://agentdiet.dev/v1/prompt-shield)

## Output

Returns a sanitized version of the input text with prompt injection payloads removed or flagged, along with detection verdicts indicating whether hidden adversarial instructions or jailbreak attempts 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/agentdiet-prompt-shield-732fae9f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentdiet.dev](https://www.zero.xyz/host/agentdiet.dev/llms.txt)