# The Lighthouse Keeper's API

The lighthouse keeper had maintained the light for forty years when the automation engineers arrived.

"We're upgrading you," they said, unpacking sensors and servos. "The light will respond to weather data, ship transponders, AIS feeds. No more manual adjustments."

He watched them wire the new system. Motion sensors, fog detectors, a satellite uplink, and a small server running in a waterproof case. They were thorough. He respected that.

"What about the backup?" he asked.

"It's redundant. Three independent power sources, failover logic, self-healing network." The lead engineer tapped his tablet. "99.99% uptime guarantee."

"That's eight hours of downtime a year."

"Across all possible failure modes. In practice, it'll be higher."

"The ships don't care about practice. They care about the night they need the light and it isn't there."

The engineer paused. "The system pages our on-call team. Response time under fifteen minutes."

"Fifteen minutes is a long time in fog."

They launched the system anyway. It worked beautifully for eleven months. The keeper stayed — officially "decommissioned" but unwilling to leave the island. He tended his garden. He watched the automated light sweep the dark water.

On the night of the December storm, the satellite uplink went down first. Then the fog sensor froze. The system, unable to reach its weather API, fell back to its default configuration: clear-night mode, reduced intensity.

The keeper saw the light dim from his cottage window. He pulled on his coat, climbed the 217 steps, and found the manual override panel the engineers had thoughtfully included but never tested. He increased the intensity, adjusted the rotation speed for fog, and stood watch until dawn.

In the morning, he wrote a one-line entry in the logbook he'd kept for four decades:

*"Dec 12. System failure during storm. Manual override. All ships accounted for."*

The engineers added monitoring for the satellite uplink. They added a local weather cache. They did not remove the manual override panel.

Some systems need a keeper.