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R on Miren

R isn't auto-detected, so you deploy it with a Dockerfile.miren. This guide uses Plumber to turn R functions into an HTTP API — a common way to serve models and data-science code.

Let your agent do this

Ask your AI coding agent to "set up this R API on Miren" after installing the Miren agent skills. It adds the Dockerfile.miren, binds Plumber to 0.0.0.0:$PORT, and deploys — using this page as its reference.

Do you need a Dockerfile?​

Yes. Miren doesn't auto-detect R, so add a Dockerfile.miren to your project root. Miren builds from it instead of guessing the stack — see Using Dockerfile.miren.

Want native support?

Miren auto-detects and builds common stacks (Python, Node, Bun, Go, Ruby, Rust) without a Dockerfile. This language isn't one of them yet — if you'd like first-class support, request it.

Bind to the injected port​

Miren injects PORT and routes traffic to it. Define endpoints in a Plumber file and run it on 0.0.0.0 at the injected port.

plumber.R:

#* @get /
#* @serializer text
function() {
  "Hello from R on Miren!\n"
}

entrypoint.R:

library(plumber)
port <- as.integer(Sys.getenv("PORT", "8080"))
pr("plumber.R") |> pr_run(host = "0.0.0.0", port = port)

The Dockerfile​

Create Dockerfile.miren in your project root. The rstudio/plumber image already has R and Plumber installed:

FROM rstudio/plumber:latest

WORKDIR /app
COPY . /app

EXPOSE 8080

If you need extra packages, install them in the build: RUN R -e 'install.packages(c("DBI", "RPostgres"))'.

.dockerignore​

.git

Set up the app​

Even with a Dockerfile.miren, Miren needs at least one service defined — it doesn't use the image's CMD as the start command. Add a Procfile:

web: Rscript /app/entrypoint.R

Then create .miren/app.toml naming your app and deploy from your project root:

name = "r-bench"
miren deploy
Deploying without a service fails

If no service is defined, the build succeeds but the deploy stops with no services defined: please define at least one service in a Procfile or .miren/app.toml.

Environment variables​

Set variables with miren env set — -e for plain values, -s for secrets (masked in output and logs). Read them with Sys.getenv("KEY"):

miren env set -e LOG_LEVEL=info
miren env set -s DATABASE_URL

You can also declare variables in .miren/app.toml:

[[env]]
key = "DATABASE_URL"
value = ""
required = true
sensitive = true

See App Configuration — Environment Variables.

Agent quick reference​

  • Detection: none — requires Dockerfile.miren
  • Base image: rstudio/plumber:latest (R + Plumber preinstalled)
  • Service is required: define a Procfile (web: Rscript /app/entrypoint.R) — the image CMD is not used
  • Port: Sys.getenv("PORT"); pr_run(host = "0.0.0.0", port = port)
  • Env vars: miren env set -e/-s; read with Sys.getenv

Next steps​