/**
 * Esplora Bitcoin API implementation
 *
 * This module implements BitcoinChainApi using the Blockstream Esplora REST API.
 * It handles balance lookup and transaction history, mapping Esplora's response
 * format to our internal activity types.
 *
 * **Key behaviours:**
 * - Balance: funded_txo_sum - spent_txo_sum from address endpoint
 * - Activities: Only confirmed txs with non-zero net (incoming/outgoing) are shown
 * - Mempool txs and net-zero (e.g. change) are omitted
 * - 'unknown' used for coinbase inputs and non-address outputs (OP_RETURN, etc.)
 */
import type { BitcoinChainApi, BitcoinBalanceData, BitcoinMempoolTx, BitcoinTxStatus, BitcoinUtxo } from './api';
import type { BitcoinTransactionActivity } from '../../activities';
import { type BitcoinTransactionId, type TransactionHex } from '../../types';
/**
 * Bitcoin chain API implementation using the Blockstream Esplora API
 *
 * Uses the Esplora REST API for balance and transaction data.
 * See: https://github.com/Blockstream/esplora/blob/master/API.md
 */
export declare class EsploraBitcoinApi implements BitcoinChainApi {
    /**
     * Creates an Esplora API client
     *
     * @param baseUrl - Esplora API base URL (e.g. https://blockstream.info/api)
     */
    constructor(baseUrl: string);
    private readonly baseUrl;
    private getUrl;
    private fetchJson;
    /**
     * {@inheritDoc BitcoinChainApi.getBalance}
     *
     * - API returns 4xx/5xx: throws (rate limit, downtime, invalid address)
     * - Success: returns funded/spent from chain_stats (balance = funded - spent)
     * - Missing chain_stats fields: default to 0
     */
    getBalance(address: string): Promise<BitcoinBalanceData>;
    /**
     * {@inheritDoc BitcoinChainApi.getActivities}
     *
     * 1. Fetch raw txs from Esplora (throws on API error, returns [] on malformed)
     * 2. Map each tx via mapEsploraTxToActivity (skips unconfirmed, net-zero)
     * 3. Sort by block number descending (newest first)
     *
     * **When activities are omitted:** Unconfirmed (mempool) txs and net-zero txs
     * (e.g. change back to self) are not included.
     */
    getActivities(address: string): Promise<BitcoinTransactionActivity[]>;
    /**
     * {@inheritDoc BitcoinChainApi.getUtxos}
     */
    getUtxos(address: string): Promise<BitcoinUtxo[]>;
    /**
     * {@inheritDoc BitcoinChainApi.getFeeRateSatsPerVByte}
     */
    getFeeRateSatsPerVByte(): Promise<number>;
    /**
     * {@inheritDoc BitcoinChainApi.getMempoolTxs}
     */
    getMempoolTxs(address: string): Promise<BitcoinMempoolTx[]>;
    /**
     * {@inheritDoc BitcoinChainApi.broadcastTransaction}
     */
    broadcastTransaction(txHex: TransactionHex): Promise<BitcoinTransactionId>;
    /**
     * {@inheritDoc BitcoinChainApi.getTxStatus}
     *
     * Esplora returns 404 for unknown txs (we report unconfirmed) and a
     * `{ confirmed, block_height? }` payload otherwise.
     */
    getTxStatus(txid: BitcoinTransactionId): Promise<BitcoinTxStatus>;
}