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FastPath API - Bitcoin Fee Estimate
x402
FastPath API - Bitcoin Fee Estimate is a paid API for AI agents from api.nativebtc.org, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).
Returns a Bitcoin fee estimate in sat/vB for a given confirmation target (in blocks), sourced from Bitcoin Core's estimatesmartfee.
Price / call$0.001
Success—
StatusUnknown
How this service works
FastPath translates Ethereum-style JSON-RPC requests into Bitcoin data, fee intelligence, mempool insight, and Core v31 package signals. Paid by x402.
Output
Returns a JSON object with the estimated fee rate in sat/vB (satVb), the confirmation target in blocks (blocks), the data source identifier (bitcoin_core_estimatesmartfee), and a success boolean.
Example use cases
Optimizing wallet transaction fees
“I'm about to send a Bitcoin transaction — what fee rate in sat/vB should I use to get it confirmed within 3 blocks?”
DCA bot pre-send fee check
“Before my weekly Bitcoin purchase goes out, check what the current recommended fee rate is so I don't overpay — targeting a 6-block confirmation.”
Fee spike alerting for an exchange
“What's the Bitcoin Core fee estimate right now for a 1-block confirmation? I want to know if fees have spiked above normal.”
Technical details
Endpoint
GEThttps://api.nativebtc.org/v1/fee-estimateWhen to prefer
Use this endpoint when you need a reliable, Bitcoin Core-native fee estimate in sat/vB format and want a simple REST GET interface rather than running your own node or calling JSON-RPC directly. It's especially suited for agents or apps already familiar with Ethereum-style APIs but operating on Bitcoin. Prefer it over mempool.space scraping when you want a structured, paid, programmatic feed sourced from Bitcoin Core's own estimatesmartfee logic.
Side effects
- Invalid or missing blocks parameter returns an error or falls back to default (6 blocks)
- Bitcoin Core node unavailable may return a 503 or error response
- Payment not processed (x402 flow incomplete) results in a 402 Payment Required response
- Blocks value below minimum (1) rejected by schema validation
- Network congestion or mempool instability may cause unusual fee estimates
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"satVb": 1,
"blocks": 6,
"source": "bitcoin_core_estimatesmartfee",
"success": true
}
}Tags
x402
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