diff --git a/NAMESPACE b/NAMESPACE
index 4b5b043..e33f67e 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -1,5 +1,6 @@
 # Generated by roxygen2: do not edit by hand
 
+export(default_allowlist)
 export(use_agent)
 export(use_ai)
 export(use_github_copilot)
diff --git a/R/aaa-shared_params.R b/R/aaa-shared_params.R
index 40a1c69..2435342 100644
--- a/R/aaa-shared_params.R
+++ b/R/aaa-shared_params.R
@@ -5,8 +5,8 @@
 #'
 #' @param agents_lines (`character`) Lines of `AGENTS.md`.
 #' @param allowlist (`character`) Hostnames to add to the GitHub Copilot coding
-#'   agent firewall allowlist. Defaults to a curated set of R and GitHub
-#'   domains.
+#'   agent firewall allowlist. Defaults to [default_allowlist()], a curated set
+#'   of R and GitHub domains.
 #' @param call (`environment`) The caller environment for error messages.
 #' @param data (`list`) Named list of whisker template variables for rendering.
 #' @param fields (`character`) Field name(s) to read from `DESCRIPTION`.
@@ -16,7 +16,7 @@
 #' @param new_row (`character(1)`) A pre-built skill row string, as produced by
 #'   `.make_skill_row()`.
 #' @param open (`logical(1)`) Whether to open the file after creation.
-#' @param overwrite (`logical(1)`) Whether to overwrite an existing file.
+#' @param overwrite (`logical(1)`) Whether to overwrite existing file(s).
 #'   Defaults to `FALSE`.
 #' @param owner (`character(1)`) GitHub repository owner (user or organization).
 #' @param repo (`character(1)`) GitHub repository name.
diff --git a/R/use_ai.R b/R/use_ai.R
index 96a094b..21e24c4 100644
--- a/R/use_ai.R
+++ b/R/use_ai.R
@@ -27,19 +27,7 @@ use_ai <- function(
   overwrite = FALSE,
   open = rlang::is_interactive(),
   gh_token = gh::gh_token(),
-  allowlist = c(
-    "api.github.com",
-    "api2r.org",
-    "bioconductor.org",
-    "cloud.r-project.org",
-    "CRAN.R-project.org",
-    "docs.github.com",
-    "r-lib.org",
-    "rstudio.github.io",
-    "tidymodels.org",
-    "tidyverse.org",
-    "wrangle.zone"
-  ),
+  allowlist = default_allowlist(),
   skills = c(
     "create-issue",
     "document",
diff --git a/R/use_github_copilot.R b/R/use_github_copilot.R
index 9301680..7c16960 100644
--- a/R/use_github_copilot.R
+++ b/R/use_github_copilot.R
@@ -4,8 +4,6 @@
 #' `.github/workflows/` directory. Also calls [use_github_copilot_whitelist()]
 #' to configure the coding agent firewall allowlist.
 #'
-#' @param overwrite (`logical(1)`) Whether to overwrite existing files. Defaults
-#'   to `FALSE`.
 #' @inheritParams .shared-params
 #' @returns The path to the installed
 #'   `.github/workflows/copilot-setup-steps.yml`, invisibly.
@@ -16,19 +14,7 @@
 use_github_copilot <- function(
   overwrite = FALSE,
   open = rlang::is_interactive(),
-  allowlist = c(
-    "api.github.com",
-    "api2r.org",
-    "bioconductor.org",
-    "cloud.r-project.org",
-    "CRAN.R-project.org",
-    "docs.github.com",
-    "r-lib.org",
-    "rstudio.github.io",
-    "tidymodels.org",
-    "tidyverse.org",
-    "wrangle.zone"
-  ),
+  allowlist = default_allowlist(),
   gh_token = gh::gh_token()
 ) {
   overwrite <- stbl::to_lgl_scalar(overwrite)
diff --git a/R/use_github_copilot_whitelist.R b/R/use_github_copilot_whitelist.R
index ccac918..d9aae0a 100644
--- a/R/use_github_copilot_whitelist.R
+++ b/R/use_github_copilot_whitelist.R
@@ -13,19 +13,7 @@
 #'
 #'   use_github_copilot_whitelist()
 use_github_copilot_whitelist <- function(
-  allowlist = c(
-    "api.github.com",
-    "api2r.org",
-    "bioconductor.org",
-    "cloud.r-project.org",
-    "CRAN.R-project.org",
-    "docs.github.com",
-    "r-lib.org",
-    "rstudio.github.io",
-    "tidymodels.org",
-    "tidyverse.org",
-    "wrangle.zone"
-  ),
+  allowlist = default_allowlist(),
   gh_token = gh::gh_token()
 ) {
   repo_parts <- .extract_repo_from_desc()
@@ -43,6 +31,37 @@ use_github_copilot_whitelist <- function(
   invisible(NULL)
 }
 
+#' Curated R and GitHub domains
+#'
+#' A curated set of R and GitHub domains to add to the GitHub Copilot coding
+#' agent firewall allowlist, or other agent domain whitelists.
+#'
+#' @returns A character vector of suggested domains.
+#' @export
+#'
+#' @examples
+#' default_allowlist()
+default_allowlist <- function() {
+  c(
+    "api.github.com",
+    "api2r.org",
+    "bioconductor.org",
+    "cloud.r-project.org",
+    "CRAN.R-project.org",
+    "docs.github.com",
+    "github.com",
+    "hadley.nz",
+    "r-lib.org",
+    "r-pkgs.org",
+    "r-project.org",
+    "rstudio.com",
+    "rstudio.github.io",
+    "tidymodels.org",
+    "tidyverse.org",
+    "wrangle.zone"
+  )
+}
+
 #' Call the GitHub API to set the Copilot allowlist
 #'
 #' @inheritParams .shared-params
diff --git a/man/default_allowlist.Rd b/man/default_allowlist.Rd
new file mode 100644
index 0000000..29c3bad
--- /dev/null
+++ b/man/default_allowlist.Rd
@@ -0,0 +1,18 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/use_github_copilot_whitelist.R
+\name{default_allowlist}
+\alias{default_allowlist}
+\title{Curated R and GitHub domains}
+\usage{
+default_allowlist()
+}
+\value{
+A character vector of suggested domains.
+}
+\description{
+A curated set of R and GitHub domains to add to the GitHub Copilot coding
+agent firewall allowlist, or other agent domain whitelists.
+}
+\examples{
+default_allowlist()
+}
diff --git a/man/dot-check_path_writable.Rd b/man/dot-check_path_writable.Rd
index da0acb5..6ee57e8 100644
--- a/man/dot-check_path_writable.Rd
+++ b/man/dot-check_path_writable.Rd
@@ -9,7 +9,7 @@
 \arguments{
 \item{path}{(\code{character(1)}) Absolute path to the file.}
 
-\item{overwrite}{(\code{logical(1)}) Whether to overwrite an existing file.
+\item{overwrite}{(\code{logical(1)}) Whether to overwrite existing file(s).
 Defaults to \code{FALSE}.}
 
 \item{call}{(\code{environment}) The caller environment for error messages.}
diff --git a/man/dot-inform_copilot_allowlist.Rd b/man/dot-inform_copilot_allowlist.Rd
index c1a877c..f98efa3 100644
--- a/man/dot-inform_copilot_allowlist.Rd
+++ b/man/dot-inform_copilot_allowlist.Rd
@@ -12,8 +12,8 @@
 \item{repo}{(\code{character(1)}) GitHub repository name.}
 
 \item{allowlist}{(\code{character}) Hostnames to add to the GitHub Copilot coding
-agent firewall allowlist. Defaults to a curated set of R and GitHub
-domains.}
+agent firewall allowlist. Defaults to \code{\link[=default_allowlist]{default_allowlist()}}, a curated set
+of R and GitHub domains.}
 }
 \value{
 \code{NULL}, invisibly.
diff --git a/man/dot-path_proj_save_as.Rd b/man/dot-path_proj_save_as.Rd
index 28d3ab8..0f30269 100644
--- a/man/dot-path_proj_save_as.Rd
+++ b/man/dot-path_proj_save_as.Rd
@@ -10,7 +10,7 @@
 \item{save_as}{(\code{character(1)}) Output file path, relative to the project
 root.}
 
-\item{overwrite}{(\code{logical(1)}) Whether to overwrite an existing file.
+\item{overwrite}{(\code{logical(1)}) Whether to overwrite existing file(s).
 Defaults to \code{FALSE}.}
 
 \item{call}{(\code{environment}) The caller environment for error messages.}
diff --git a/man/dot-set_copilot_allowlist.Rd b/man/dot-set_copilot_allowlist.Rd
index 00cca5f..bfc042e 100644
--- a/man/dot-set_copilot_allowlist.Rd
+++ b/man/dot-set_copilot_allowlist.Rd
@@ -12,8 +12,8 @@
 \item{repo}{(\code{character(1)}) GitHub repository name.}
 
 \item{allowlist}{(\code{character}) Hostnames to add to the GitHub Copilot coding
-agent firewall allowlist. Defaults to a curated set of R and GitHub
-domains.}
+agent firewall allowlist. Defaults to \code{\link[=default_allowlist]{default_allowlist()}}, a curated set
+of R and GitHub domains.}
 
 \item{gh_token}{(\code{character(1)}) A GitHub personal access token. Defaults to
 \code{gh::gh_token()}.}
diff --git a/man/dot-shared-params.Rd b/man/dot-shared-params.Rd
index 3cbbc6d..f454fca 100644
--- a/man/dot-shared-params.Rd
+++ b/man/dot-shared-params.Rd
@@ -7,8 +7,8 @@
 \item{agents_lines}{(\code{character}) Lines of \code{AGENTS.md}.}
 
 \item{allowlist}{(\code{character}) Hostnames to add to the GitHub Copilot coding
-agent firewall allowlist. Defaults to a curated set of R and GitHub
-domains.}
+agent firewall allowlist. Defaults to \code{\link[=default_allowlist]{default_allowlist()}}, a curated set
+of R and GitHub domains.}
 
 \item{call}{(\code{environment}) The caller environment for error messages.}
 
@@ -26,7 +26,7 @@ domains.}
 
 \item{open}{(\code{logical(1)}) Whether to open the file after creation.}
 
-\item{overwrite}{(\code{logical(1)}) Whether to overwrite an existing file.
+\item{overwrite}{(\code{logical(1)}) Whether to overwrite existing file(s).
 Defaults to \code{FALSE}.}
 
 \item{owner}{(\code{character(1)}) GitHub repository owner (user or organization).}
diff --git a/man/dot-use_skill.Rd b/man/dot-use_skill.Rd
index f257ae4..f44aedc 100644
--- a/man/dot-use_skill.Rd
+++ b/man/dot-use_skill.Rd
@@ -28,7 +28,7 @@ installed, relative to the project root. Defaults to \code{".github"}.}
 under a \code{skills} subdirectory of \code{target_dir}. Defaults to \code{TRUE},
 producing \code{.github/skills/{skill}/SKILL.md}.}
 
-\item{overwrite}{(\code{logical(1)}) Whether to overwrite an existing file.
+\item{overwrite}{(\code{logical(1)}) Whether to overwrite existing file(s).
 Defaults to \code{FALSE}.}
 
 \item{open}{(\code{logical(1)}) Whether to open the file after creation.}
diff --git a/man/dot-use_template_as_is.Rd b/man/dot-use_template_as_is.Rd
index 415ba9e..6852c88 100644
--- a/man/dot-use_template_as_is.Rd
+++ b/man/dot-use_template_as_is.Rd
@@ -16,7 +16,7 @@
 \item{save_as}{(\code{character(1)}) Output file path, relative to the project
 root.}
 
-\item{overwrite}{(\code{logical(1)}) Whether to overwrite an existing file.
+\item{overwrite}{(\code{logical(1)}) Whether to overwrite existing file(s).
 Defaults to \code{FALSE}.}
 
 \item{open}{(\code{logical(1)}) Whether to open the file after creation.}
diff --git a/man/use_agent.Rd b/man/use_agent.Rd
index 39e7860..987e109 100644
--- a/man/use_agent.Rd
+++ b/man/use_agent.Rd
@@ -14,7 +14,7 @@ use_agent(
 \item{save_as}{(\code{character(1)}) Output file path, relative to the project
 root.}
 
-\item{overwrite}{(\code{logical(1)}) Whether to overwrite an existing file.
+\item{overwrite}{(\code{logical(1)}) Whether to overwrite existing file(s).
 Defaults to \code{FALSE}.}
 
 \item{open}{(\code{logical(1)}) Whether to open the file after creation.}
diff --git a/man/use_ai.Rd b/man/use_ai.Rd
index bf47169..01fd672 100644
--- a/man/use_ai.Rd
+++ b/man/use_ai.Rd
@@ -11,9 +11,7 @@ use_ai(
   overwrite = FALSE,
   open = rlang::is_interactive(),
   gh_token = gh::gh_token(),
-  allowlist = c("api.github.com", "api2r.org", "bioconductor.org", "cloud.r-project.org",
-    "CRAN.R-project.org", "docs.github.com", "r-lib.org", "rstudio.github.io",
-    "tidymodels.org", "tidyverse.org", "wrangle.zone"),
+  allowlist = default_allowlist(),
   skills = c("create-issue", "document", "github", "implement-issue", "r-code",
     "search-code", "tdd-workflow")
 )
@@ -29,7 +27,7 @@ installed. Passed to all \verb{use_skill_*()} functions as \code{target_dir}.}
 under a \code{skills} subdirectory of \code{target_dir}. Defaults to \code{TRUE},
 producing \code{.github/skills/{skill}/SKILL.md}.}
 
-\item{overwrite}{(\code{logical(1)}) Whether to overwrite an existing file.
+\item{overwrite}{(\code{logical(1)}) Whether to overwrite existing file(s).
 Defaults to \code{FALSE}.}
 
 \item{open}{(\code{logical(1)}) Whether to open the file after creation.}
@@ -38,8 +36,8 @@ Defaults to \code{FALSE}.}
 \code{gh::gh_token()}.}
 
 \item{allowlist}{(\code{character}) Hostnames to add to the GitHub Copilot coding
-agent firewall allowlist. Defaults to a curated set of R and GitHub
-domains.}
+agent firewall allowlist. Defaults to \code{\link[=default_allowlist]{default_allowlist()}}, a curated set
+of R and GitHub domains.}
 
 \item{skills}{(\code{character}) Which skills to install. Defaults to all known
 skills. Pass a subset to install only specific skills, or \code{character(0)}
diff --git a/man/use_github_copilot.Rd b/man/use_github_copilot.Rd
index 5de6196..7276c09 100644
--- a/man/use_github_copilot.Rd
+++ b/man/use_github_copilot.Rd
@@ -7,21 +7,19 @@
 use_github_copilot(
   overwrite = FALSE,
   open = rlang::is_interactive(),
-  allowlist = c("api.github.com", "api2r.org", "bioconductor.org", "cloud.r-project.org",
-    "CRAN.R-project.org", "docs.github.com", "r-lib.org", "rstudio.github.io",
-    "tidymodels.org", "tidyverse.org", "wrangle.zone"),
+  allowlist = default_allowlist(),
   gh_token = gh::gh_token()
 )
 }
 \arguments{
-\item{overwrite}{(\code{logical(1)}) Whether to overwrite existing files. Defaults
-to \code{FALSE}.}
+\item{overwrite}{(\code{logical(1)}) Whether to overwrite existing file(s).
+Defaults to \code{FALSE}.}
 
 \item{open}{(\code{logical(1)}) Whether to open the file after creation.}
 
 \item{allowlist}{(\code{character}) Hostnames to add to the GitHub Copilot coding
-agent firewall allowlist. Defaults to a curated set of R and GitHub
-domains.}
+agent firewall allowlist. Defaults to \code{\link[=default_allowlist]{default_allowlist()}}, a curated set
+of R and GitHub domains.}
 
 \item{gh_token}{(\code{character(1)}) A GitHub personal access token. Defaults to
 \code{gh::gh_token()}.}
@@ -31,10 +29,9 @@ The path to the installed
 \code{.github/workflows/copilot-setup-steps.yml}, invisibly.
 }
 \description{
-Installs a \code{copilot-setup-steps.yml} workflow and its companion reusable
-\code{install} action into the project's \verb{.github/workflows/} directory. Also
-calls \code{\link[=use_github_copilot_whitelist]{use_github_copilot_whitelist()}} to configure the coding agent firewall
-allowlist.
+Installs a \code{copilot-setup-steps.yml} workflow into the project's
+\verb{.github/workflows/} directory. Also calls \code{\link[=use_github_copilot_whitelist]{use_github_copilot_whitelist()}}
+to configure the coding agent firewall allowlist.
 }
 \examples{
 \dontshow{if (interactive()) withAutoprint(\{ # examplesIf}
diff --git a/man/use_github_copilot_whitelist.Rd b/man/use_github_copilot_whitelist.Rd
index 40640f5..547916a 100644
--- a/man/use_github_copilot_whitelist.Rd
+++ b/man/use_github_copilot_whitelist.Rd
@@ -5,16 +5,14 @@
 \title{Update the GitHub Copilot coding agent firewall allowlist}
 \usage{
 use_github_copilot_whitelist(
-  allowlist = c("api.github.com", "api2r.org", "bioconductor.org", "cloud.r-project.org",
-    "CRAN.R-project.org", "docs.github.com", "r-lib.org", "rstudio.github.io",
-    "tidymodels.org", "tidyverse.org", "wrangle.zone"),
+  allowlist = default_allowlist(),
   gh_token = gh::gh_token()
 )
 }
 \arguments{
 \item{allowlist}{(\code{character}) Hostnames to add to the GitHub Copilot coding
-agent firewall allowlist. Defaults to a curated set of R and GitHub
-domains.}
+agent firewall allowlist. Defaults to \code{\link[=default_allowlist]{default_allowlist()}}, a curated set
+of R and GitHub domains.}
 
 \item{gh_token}{(\code{character(1)}) A GitHub personal access token. Defaults to
 \code{gh::gh_token()}.}
diff --git a/man/use_skill_create_issue.Rd b/man/use_skill_create_issue.Rd
index 058e943..e650df8 100644
--- a/man/use_skill_create_issue.Rd
+++ b/man/use_skill_create_issue.Rd
@@ -20,7 +20,7 @@ installed, relative to the project root. Defaults to \code{".github"}.}
 under a \code{skills} subdirectory of \code{target_dir}. Defaults to \code{TRUE},
 producing \code{.github/skills/{skill}/SKILL.md}.}
 
-\item{overwrite}{(\code{logical(1)}) Whether to overwrite an existing file.
+\item{overwrite}{(\code{logical(1)}) Whether to overwrite existing file(s).
 Defaults to \code{FALSE}.}
 
 \item{open}{(\code{logical(1)}) Whether to open the file after creation.}
diff --git a/man/use_skill_document.Rd b/man/use_skill_document.Rd
index 91a6f9d..c473bff 100644
--- a/man/use_skill_document.Rd
+++ b/man/use_skill_document.Rd
@@ -19,7 +19,7 @@ installed, relative to the project root. Defaults to \code{".github"}.}
 under a \code{skills} subdirectory of \code{target_dir}. Defaults to \code{TRUE},
 producing \code{.github/skills/{skill}/SKILL.md}.}
 
-\item{overwrite}{(\code{logical(1)}) Whether to overwrite an existing file.
+\item{overwrite}{(\code{logical(1)}) Whether to overwrite existing file(s).
 Defaults to \code{FALSE}.}
 
 \item{open}{(\code{logical(1)}) Whether to open the file after creation.}
diff --git a/man/use_skill_github.Rd b/man/use_skill_github.Rd
index 08692d5..701a6b3 100644
--- a/man/use_skill_github.Rd
+++ b/man/use_skill_github.Rd
@@ -19,7 +19,7 @@ installed, relative to the project root. Defaults to \code{".github"}.}
 under a \code{skills} subdirectory of \code{target_dir}. Defaults to \code{TRUE},
 producing \code{.github/skills/{skill}/SKILL.md}.}
 
-\item{overwrite}{(\code{logical(1)}) Whether to overwrite an existing file.
+\item{overwrite}{(\code{logical(1)}) Whether to overwrite existing file(s).
 Defaults to \code{FALSE}.}
 
 \item{open}{(\code{logical(1)}) Whether to open the file after creation.}
diff --git a/man/use_skill_implement_issue.Rd b/man/use_skill_implement_issue.Rd
index 8df2a5f..478b893 100644
--- a/man/use_skill_implement_issue.Rd
+++ b/man/use_skill_implement_issue.Rd
@@ -19,7 +19,7 @@ installed, relative to the project root. Defaults to \code{".github"}.}
 under a \code{skills} subdirectory of \code{target_dir}. Defaults to \code{TRUE},
 producing \code{.github/skills/{skill}/SKILL.md}.}
 
-\item{overwrite}{(\code{logical(1)}) Whether to overwrite an existing file.
+\item{overwrite}{(\code{logical(1)}) Whether to overwrite existing file(s).
 Defaults to \code{FALSE}.}
 
 \item{open}{(\code{logical(1)}) Whether to open the file after creation.}
diff --git a/man/use_skill_r_code.Rd b/man/use_skill_r_code.Rd
index 8ddd8d1..a083284 100644
--- a/man/use_skill_r_code.Rd
+++ b/man/use_skill_r_code.Rd
@@ -19,7 +19,7 @@ installed, relative to the project root. Defaults to \code{".github"}.}
 under a \code{skills} subdirectory of \code{target_dir}. Defaults to \code{TRUE},
 producing \code{.github/skills/{skill}/SKILL.md}.}
 
-\item{overwrite}{(\code{logical(1)}) Whether to overwrite an existing file.
+\item{overwrite}{(\code{logical(1)}) Whether to overwrite existing file(s).
 Defaults to \code{FALSE}.}
 
 \item{open}{(\code{logical(1)}) Whether to open the file after creation.}
diff --git a/man/use_skill_search_code.Rd b/man/use_skill_search_code.Rd
index f72c675..9dfe1fb 100644
--- a/man/use_skill_search_code.Rd
+++ b/man/use_skill_search_code.Rd
@@ -19,7 +19,7 @@ installed, relative to the project root. Defaults to \code{".github"}.}
 under a \code{skills} subdirectory of \code{target_dir}. Defaults to \code{TRUE},
 producing \code{.github/skills/{skill}/SKILL.md}.}
 
-\item{overwrite}{(\code{logical(1)}) Whether to overwrite an existing file.
+\item{overwrite}{(\code{logical(1)}) Whether to overwrite existing file(s).
 Defaults to \code{FALSE}.}
 
 \item{open}{(\code{logical(1)}) Whether to open the file after creation.}
diff --git a/man/use_skill_tdd_workflow.Rd b/man/use_skill_tdd_workflow.Rd
index 7c1d089..7bb60d2 100644
--- a/man/use_skill_tdd_workflow.Rd
+++ b/man/use_skill_tdd_workflow.Rd
@@ -19,7 +19,7 @@ installed, relative to the project root. Defaults to \code{".github"}.}
 under a \code{skills} subdirectory of \code{target_dir}. Defaults to \code{TRUE},
 producing \code{.github/skills/{skill}/SKILL.md}.}
 
-\item{overwrite}{(\code{logical(1)}) Whether to overwrite an existing file.
+\item{overwrite}{(\code{logical(1)}) Whether to overwrite existing file(s).
 Defaults to \code{FALSE}.}
 
 \item{open}{(\code{logical(1)}) Whether to open the file after creation.}