Atomic Batches

Normal writes wait for the game thread, so a shell loop lands one command per frame. A batch validates every line first, then executes the whole group in order in one tick. Very useful for formations, coordinated FX, and a suspiciously well-timed party light switch.

/sim (in guest)

cat > /sim/ctl/batch <<'EOF'
vessels/active/ctl/lights 1
vessels/active/ctl/rcs 1
commit
EOF

HTTP (host)

curl -X POST --data $'vessels/active/ctl/lights 1\nvessels/active/ctl/rcs 1\ncommit\n' \
  http://127.0.0.1:4242/v1/fs/ctl/batch

Paths are /sim-relative, though bare and /sim/-rooted spellings also work. Close without commit and the unfinished batch is discarded. A failing path or value rejects the whole submission before anything fires.

Same tick means same phase

Every command in a batch must be Frame phase or Solver phase, never both. ctl/lights is Frame; ctl/attitude_mode is Solver. Mixing them returns EINVAL, because those drains are different moments. The limit is 64 commands and 64 KiB.

Next: Timed sequences spread the same command language over a clock.

Next: Timed sequencesRun launch cues, lighting, or control changes along a host-owned timeline.