# Bittensor Subnet Registration Cost History

> Bittensor Subnet Registration Cost History is a paid API for AI agents from api.carbon-cashmere.de, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Returns hourly NeuronRegistered event counts and current burn-cost per Bittensor subnet, enabling prediction of cheap-registration windows.

## Facts

- Endpoint: GET https://api.carbon-cashmere.de/v1/bittensor-derivatives/registration-cost-history
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-carbon-cashmere-de-6a93116d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_t3ba4Vy4NMt85yvEDntE6

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 api-carbon-cashmere-de-6a93116d
```

Example prompt: Show me the hourly NeuronRegistered event counts and current burn costs for all Bittensor subnets so I can figure out the cheapest window to register a new neuron.

## When to prefer this

Choose this endpoint when you need historical and current Bittensor subnet registration cost data to time a neuron registration cheaply, or when monitoring registration pressure across subnets over time. Prefer over general Bittensor metagraph snapshots when the specific goal is cost-timing for registration.

## Known failure modes

- Invalid or unknown netuid returns 404 or empty data
- Subtensor node connectivity issues causing stale or missing data
- Rate limiting if called too frequently
- Malformed request parameters return 400 bad request

## How this service works

Hourly Bittensor subnet registration activity (NeuronRegistered event count per subnet) + current burn-cost per subnet. Useful for predicting cheap-registration windows.

## Output

Returns hourly NeuronRegistered event counts per Bittensor subnet alongside the current burn cost (TAO) for each subnet, allowing identification of low-activity registration windows where costs are minimized.

## Example request

```json
{
 "properties": "netuid"
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "window": "24h",
  "activity": [
   {
    "hour": "...",
    "netuid": 18,
    "registrations": 5,
    "current_burn_tao": 1
   }
  ],
  "current_burn_by_subnet": {
   "18": 1,
   "26": 0.5
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-carbon-cashmere-de-6a93116d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.carbon-cashmere.de](https://www.zero.xyz/host/api.carbon-cashmere.de/llms.txt)