# KHOTEM Open Stream Topup

> KHOTEM Open Stream Topup is a paid API for AI agents from khotem.com, paid per call via x402, $0.5/call, status unknown (last checked 2026-09-14).

Tops up an existing KHOTEM cryptographic witness stream by adding 1000 more messages to its message quota

## Facts

- Endpoint: POST https://khotem.com/api/a1/open
- Price: $0.5/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/khotem-open-stream-topup-44473310
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_-Lu0qFAtD5PwVAPRBddtr

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 khotem-open-stream-topup-44473310 -d '<json body>'
```

Example prompt: My KHOTEM witness stream stream_abc123 is almost out of message credits — go ahead and top it up with 1000 more messages using my USDC wallet.

## When to prefer this

Use this endpoint when you have an active KHOTEM cryptographic witness stream that is approaching its message limit and needs to be extended without creating a new stream. This is the correct endpoint when you already hold a valid stream_id and want to continue using the same sealed document thread or audit trail without interruption. Prefer this over opening a new stream when continuity of the attestation chain matters.

## Known failure modes

- Invalid or unknown stream_id returns an error indicating the stream does not exist
- Expired or closed stream cannot be topped up
- Payment failure via x402 results in 402 response and no quota change
- Malformed request body returns a validation error
- Stream already at maximum capacity may reject topup

## How this service works

Paid cryptographic witness services for autonomous agents and humans: seals, attestations, verification, audit, sealed document thread. x402-native micropayments, USDC on Base / Polygon / Solana, direct on-chain verification. No accounts, no API keys, no KYC.

## Output

Returns confirmation that 1000 additional messages have been added to the specified stream, along with updated stream metadata such as new message quota and current usage. Payment of $0.50 USDC is processed on-chain via x402 before the topup is applied.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "topup": {
   "type": "string",
   "description": "existing stream_id to add 1000 more messages"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/khotem-open-stream-topup-44473310/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from khotem.com](https://www.zero.xyz/host/khotem.com/llms.txt)