# X402 Delivery Content Type Check

> X402 Delivery Content Type Check is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Validates whether an x402 delivery's content type matches the buyer's accepted media types, returning acceptance/rejection status with mismatch reasons

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/x402-delivery-content-type-check
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-delivery-content-type-check-706e3c3d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_J-D5fHcQ_ittQpIV2Wikx

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 x402-delivery-content-type-check-706e3c3d -d '<json body>'
```

Example prompt: Before I pay for this x402 delivery, check whether the content type 'application/json' is acceptable given my accepted types list ['application/json', 'text/plain'] — I need an explicit accept or reject with any mismatch reasons.

## When to prefer this

Use this endpoint specifically when operating in an x402 or agent delivery context where you need to validate a delivery's content type against a buyer-specified list of accepted media types before committing to payment or processing. Prefer this over manual string matching when you need normalized evidence, structured mismatch reasons, and an explicit contract-level accept/reject decision. It is lightweight ($0.001 USDC) and stateless, making it suitable for inline pre-payment validation steps in automated agent workflows.

## Known failure modes

- Missing or empty content_type field causes check to fail with no meaningful result
- Empty accepted array may result in automatic rejection of any content type
- Malformed MIME type strings may cause parsing errors or unexpected match behavior
- Overly broad wildcard accepted types (e.g. '*/*') may accept unintended content types

## How this service works

X402 Delivery Content Type Check: X402 Delivery Content Type Check compares delivery content type with buyer-accepted media types from bounded caller-supplied values without an external provider. Call X402 Delivery Content Type Check before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Delivery Content…

## Output

Returns a structured result including an explicit acceptance or rejection status, normalized evidence of the content type comparison, contract-specific validation checks, and human-readable mismatch reasons explaining why the content type was accepted or rejected.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "accepted": {
   "type": "array",
   "items": {
    "type": "string",
    "maxLength": 8192
   },
   "maxItems": 256,
   "description": "Accepted supplied to X402 Delivery Content Type Check; used only for this bounded calculation and processed in memory without retention."
  },
  "content_type": {
   "type": "string",
   "maxLength": 8192,
   "description": "Content Type supplied to X402 Delivery Content Type Check; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "accepted": true,
   "content_type": "application/json"
  },
  "schema": "delx/util-x402-delivery-content-type-check/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "17d22f796e7932f46bbb49530f843fcbb42e7bea6267a2306a495865b24fc926",
   "external_calls": 0
  },
  "operation": "delivery_contract:x402_delivery_content_type_check"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-delivery-content-type-check-706e3c3d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)