/**
 * Which field-naming schema a deployed August vault subgraph uses:
 * - `'old'` — snake_case fields (`block_number`, `timestamp_`, `transactionHash_`).
 * - `'new'` — camelCase fields (`blockNumber`, `blockTimestamp`, `transactionHash`).
 *
 * The two templates are otherwise equivalent; the SDK aliases new-schema fields
 * back to the old internal names when querying, so the rest of the code only ever
 * sees the old (snake_case) shape.
 */
export type SubgraphSchema = 'old' | 'new';
/**
 * True when a GraphQL error array reports an unknown field on the queried type
 * (message contains "has no field") — the signature of a schema mismatch.
 *
 * @param errors - GraphQL `errors` array from a subgraph response (may be undefined).
 * @returns `true` if any error message indicates an unknown field, else `false`.
 */
export declare function isSubgraphSchemaFieldError(errors: {
    message?: string;
}[] | undefined): boolean;
/**
 * Detects whether a deployed subgraph uses the old or new field schema by probing
 * a single field (`blockTimestamp`) that exists only on the new template, on
 * `withdrawalRequesteds`, or on `transfers` for a receipt-token subgraph that
 * has no `withdrawalRequesteds` entity.
 *
 * This replaces the previous heuristic — "vault symbol present in the deprecated
 * `SUBGRAPH_VAULT_URLS` map ⇒ old schema, else new" — which mis-guessed any
 * newly-added vault whose subgraph shipped on the old template (e.g.
 * `august-citrea-earn-ctusd`). A wrong guess made every subgraph read query
 * non-existent field names, so the subgraph returned GraphQL errors with no
 * `data` and the SDK silently returned empty sets — emptying the Pending
 * Withdrawals and History tabs for that vault.
 *
 * Because the schema is immutable for a fixed subgraph deployment, the result is
 * cached per URL ({@link SCHEMA_TTL_MS}); across a page's positions/history/
 * withdrawals reads this amounts to a single extra lightweight query per subgraph.
 *
 * Side effects: at most two HTTP POSTs to the subgraph per URL per TTL window
 * (the second only for a subgraph without `withdrawalRequesteds`).
 *
 * @param goldskyUrl - Fully-qualified subgraph GraphQL endpoint.
 * @param apiKey - Optional Goldsky API key sent as a Bearer token.
 * @returns `'old'` or `'new'`. Defaults to `'new'` when the URL is empty or the
 *   probe is inconclusive (network error / unexpected response) — the schema the
 *   majority of current vaults use.
 */
export declare function resolveSubgraphSchema(goldskyUrl: string, apiKey?: string): Promise<SubgraphSchema>;