Search depth
How many plies ahead the engine has fully searched; cost grows about 1.6× per ply.
Depth 20 means the main line has been examined 20 half-moves deep, with selective extensions going further. Each extra ply costs roughly 1.6× more nodes, so depth 30 costs about 100× more than depth 20. For most purposes depth 14 to 18 is enough to pick a good move; depth 24+ is for analysis you will publish. This API prices requests by the node budget a depth implies, so GET /v1/price tells you the cost before you call.
Example
curl -s https://stockfishapi.com/v1/eval \
-H "Authorization: Bearer $STOCKFISH_API_KEY" \
-H "Content-Type: application/json" \
-d '{"fen":"r1bqkb1r/pppp1ppp/2n2n2/1B2p3/4P3/5N2/PPPP1PPP/RNBQK2R w KQkq - 4 4","depth":14}'const res = await fetch("https://stockfishapi.com/v1/eval", {
method: "POST",
headers: { Authorization: `Bearer ${process.env.STOCKFISH_API_KEY}`, "Content-Type": "application/json" },
body: JSON.stringify({
"fen": "r1bqkb1r/pppp1ppp/2n2n2/1B2p3/4P3/5N2/PPPP1PPP/RNBQK2R w KQkq - 4 4",
"depth": 14
}),
});
const data = await res.json();import os, requests
r = requests.post(
"https://stockfishapi.com/v1/eval",
headers={"Authorization": f"Bearer {os.environ['STOCKFISH_API_KEY']}"},
json={
"fen": "r1bqkb1r/pppp1ppp/2n2n2/1B2p3/4P3/5N2/PPPP1PPP/RNBQK2R w KQkq - 4 4",
"depth": 14
},
)
data = r.json()