# Bitcoin Fee Rate Tiers (obol-x402)

> Bitcoin Fee Rate Tiers (obol-x402) is a paid API for AI agents from obol-x402.fly.dev, paid per call via x402, $0.01/call, status down (last checked 2026-09-15).

Returns current Bitcoin recommended fee rates in sat/vB across five tiers: next-block, 30-min, 1-hour, economy, and minimum — with Ed25519 cryptographic signature on every response.

## Facts

- Endpoint: GET https://obol-x402.fly.dev/v1/btc/fee/tiers
- Price: $0.01/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/bitcoin-fee-rate-tiers-obol-x402-b3d9690e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yF_L_5b8-CWFUXp3GxJQ1

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 bitcoin-fee-rate-tiers-obol-x402-b3d9690e
```

Example prompt: What are the current Bitcoin fee rates across all confirmation tiers — next-block, 30-minute, 1-hour, economy, and minimum — in sat/vB, with a verifiable signed response?

## When to prefer this

Choose this endpoint when you need real-time Bitcoin fee rate tiers across multiple confirmation speed buckets and want cryptographic proof of authenticity on each response. Particularly suited for wallets, fee estimation UIs, and AI agents that need trustworthy, signed fee data rather than raw unsigned mempool queries.

## Known failure modes

- Upstream mempool data source unavailable — may return 5xx or stale data
- Payment of $0.01 USDC not processed — returns 402 Payment Required
- Network timeout connecting to obol-x402.fly.dev — request times out
- Signature verification fails if public key endpoint is unreachable

## How this service works

Bitcoin recommended fee rates sat/vB: next-block, 30-min, 1-hour, economy, minimum. Fee estimation tiers for AI agents and fee estimation UIs. Cryptographically signed (Ed25519) — every response is independently verifiable via /.well-known/obol-pubkey.

## Output

A JSON object containing recommended Bitcoin fee rates in sat/vB for five tiers (next-block, 30-min, 1-hour, economy, minimum), along with an Ed25519 cryptographic signature that can be independently verified via the provider's public key endpoint.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bitcoin-fee-rate-tiers-obol-x402-b3d9690e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from obol-x402.fly.dev](https://www.zero.xyz/host/obol-x402.fly.dev/llms.txt)