fingertip

at your fingertips (especially of information) readily available.

by your fingertips only with difficulty; barely.

2009Iain PearsStone's Fall A few houses were owned by shopkeepers or clerks desperately clinging to respectability by their fingertips.

to your fingertips totally; completely.

1991Sun McMahon, a professional to his fingertips, gave it his best shot even though an injury at this delicate stage could have sabotaged the last big move of his career.