@parity/product-sdk-signer

--- package/src/providers/dev.ts (excerpt) ---
// Copyright 2026 Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: Apache-2.0
import { seedToAccount } from "@parity/product-sdk-keys";
import { createLogger } from "@parity/product-sdk-logger";

import type { SignerError } from "../errors.js";
import type { Result, SignerAccount } from "../types.js";
import { ok } from "../types.js";
import type { SignerProvider, Unsubscribe } from "./types.js";

const log = createLogger("signer:dev");

/** The well-known Substrate development mnemonic phrase. */
const DEV_PHRASE = "bottom drive obey lake curtain smoke basket hold race lonely fit walk";

/** Standard Substrate dev account names. */
const DEFAULT_DEV_NAMES = ["Alice", "Bob", "Charlie", "Dave", "Eve", "Ferdie"] as const;

/** A well-known Substrate development account name (Alice, Bob, …) used to derive deterministic dev accounts from the standard Substrate dev mnemonic. */
export type DevAccountName = (typeof DEFAULT_DEV_NAMES)[number];

/** Supported key types for dev account derivation. */
export type DevKeyType = "sr25519" | "ed25519";

/** Options for the dev account provider. */
export interface DevProviderOptions {
    /** Which dev accounts to create. Default: all 6 standard accounts. */
    names?: readonly string[];
    /** Custom mnemonic phrase instead of DEV_PHRASE. */
    mnemonic?: string;
    /** SS58 prefix for address encoding. Default: 42 */
    ss58Prefix?: number;
    /** Key type for account derivation. Default: "sr25519" */
    keyType?: DevKeyT