# Tinkrr Bitcoin Fee Forecast API

> Tinkrr Bitcoin Fee Forecast API is a paid API for AI agents from tinkrr-api.tinkrr.workers.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Returns real-time Bitcoin transaction fee estimates for next-block, 30-minute, and 1-hour confirmation windows along with a mempool congestion tier

## Facts

- Endpoint: GET https://tinkrr-api.tinkrr.workers.dev/btc/fees
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tinkrr-bitcoin-fee-forecast-api-79250d09
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oPXi2ulwSpwkjGpCVig6C

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 tinkrr-bitcoin-fee-forecast-api-79250d09
```

Example prompt: What are the current Bitcoin transaction fees — give me the next-block, 30-minute, and 1-hour estimates along with whether congestion is low, medium, high, or critical right now?

## When to prefer this

Choose this endpoint when you need a quick, structured Bitcoin fee forecast with explicit congestion classification and multi-window estimates (next-block, 30-min, 1-hr) in a single call. Prefer it over raw mempool explorers when you need a clean API with congestion tier labels suitable for automated decision-making in wallets, payment processors, or DeFi tooling.

## Known failure modes

- Payment not included or invalid x402 payment header — returns 402 Payment Required
- Upstream mempool data unavailable — returns 503 or stale data
- Rate limit exceeded — returns 429 Too Many Requests
- Malformed request — returns 400 Bad Request

## How this service works

Real-time Bitcoin fee forecast: next-block, 30-min, 1-hr with congestion tier

## Output

Returns a JSON object containing fee rate estimates (in sat/vB or similar unit) for next-block, 30-minute, and 1-hour confirmation targets, a congestion tier enum ('low', 'medium', 'high', or 'critical'), example cost breakdowns, and timing metadata reflecting current mempool conditions.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "properties": {
  "input": {
   "type": "object",
   "properties": {
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   }
  },
  "output": {
   "type": "object",
   "properties": {
    "schema": {
     "type": "object",
     "properties": {
      "timing": {
       "type": "object"
      },
      "estimates": {
       "type": "object"
      },
      "congestion": {
       "enum": [
        "low",
        "medium",
        "high",
        "critical"
       ],
       "type": "string"
      },
      "exampleCosts": {
       "type": "object"
      }
     }
    },
    "example": {
     "estimates": {
      "oneHour": {
       "low": 3,
       "mid": 4,
       "high": 5
      },
      "nextBlock": {
       "low": 5,
       "mid": 6,
       "high": 7
      },
      "thirtyMin": {
       "low": 4,
       "mid": 5,
       "high": 6
      }
     },
     "congestion": "low",
     "exampleCosts": {
      "oneHour_sats": 564,
      "p2wpkh_vbytes": 141,
      "nextBlock_sats": 846
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/tinkrr-bitcoin-fee-forecast-api-79250d09/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from tinkrr-api.tinkrr.workers.dev](https://www.zero.xyz/host/tinkrr-api.tinkrr.workers.dev/llms.txt)