Quickstart: R

Build a working study in R in a few minutes. For the full API, see the R SDK reference.

Install psycloudr

# install.packages("remotes")
remotes::install_github("bbuchsbaum/psycloud", subdir = "packages/psycloudr")

Write a study

Save this as hello-rt.R. It builds a minimal reaction-time task — a colored circle appears after a fixation cross, and the participant presses any key.

hello-rt.R

library(psycloudr)
 
bundle <- experiment(id = "hello.rt", name = "Hello, psycloudr") |>
  instructions(markdown(
    "# Reaction Time\n\nPress any key when the circle appears."
  )) |>
  phase("main", label = "Trials") |>
    factors(color = c("tomato", "steelblue")) |>
    cross() |>
    repeat_rows(3) |>
    shuffle(seed = seed_per_participant("hello-rt")) |>
  screen("trial") |>
    present(fixation_cross(x = "center", y = "center", size = 40), 700) |>
    ask(circle(x = "center", y = "center", radius = 60, fill = trial$color), anykey()) |>
    record(color) |>
  end_screen(markdown("# Done\n\nThanks!")) |>
  bundle(with_auto_ids = TRUE)

Inspect and write the bundle

psycloud(bundle)                                   # inline preview in RStudio
write_bundle(bundle, dir = "hello_rt_bundle", overwrite = TRUE)

Run or edit it
Validate or compile the bundle with the CLI, or open hello_rt_bundle/ in Studio via New Study → Import bundle to keep editing visually.

Dynamic values

trial$color binds each trial's value into the circle's fill. The expression DSL covers conditionals (case_when, expr_if), derived columns, and response-based logic.

Quickstart: R

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