This NodeJS CLI app implements a subset of the ChessSrs functionality described here
Video link

• Add multiple "subrepertoires" from PGN strings
• Learn openings
• Recall openings

add
1. d4 d5 2. c4 e6 3. Nf3 Nf6 4. g3

select
0

next
Type "next" until there are no more trainable positions

Switch to recall
toggle
next

Guess the move --> enter a move in valid SAN (case-sensitive)
d4

Continue recalling
next
[guess]