vs
| Measure | Callbook AI | Earendil Robotics |
|---|---|---|
| Batch | Summer 2026 | Summer 2026 |
| Team size | 7 | 7 |
| Stage | Early | Early |
| Status | Active | Active |
| Industry | B2B | Industrials |
| Sectors | AI | Drones, Swarm Robotics, AR |
| Based | San Francisco | San Francisco |
| Year founded | 2025 | 2025 |
| Open roles | 0 | 0 |
| Founders | 2 | 2 |
| Group partner | Jon Xu | not stated |
Click a column heading to sort. A cell reading "not stated" means that record does not carry the figure — it is never filled in from the other side, and never guessed.
Callbook AI
7
people — bigger than that share of the Summer 2026 batch
Against the 209 companies on file from Summer 2026. Median team 2, largest 30.
Earendil Robotics
7
people — bigger than that share of the Summer 2026 batch
Against the 209 companies on file from Summer 2026. Median team 2, largest 30.
Callbook AI
Earendil Robotics
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Watchlist Callbook AIBoth profiles in full: Callbook AI · Earendil Robotics.
Both sides are read from the Y Combinator directory — Callbook AI and Earendil Robotics. Figures are read directly from the source record; names have not been matched against other people.