diff --git a/NAMESPACE b/NAMESPACE
index 52acf81..babda05 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -3,6 +3,7 @@
 export(any_local_behind_lockfile)
 export(capshot)
 export(capshot_str)
+export(capsule_sources)
 export(compare_capsule_to_lockfile)
 export(compare_local_to_lockfile)
 export(create)
diff --git a/R/capshot.R b/R/capshot.R
index a2d8d92..fe21194 100644
--- a/R/capshot.R
+++ b/R/capshot.R
@@ -50,13 +50,14 @@ BASE_PACKAGES <-
 #' be integrated into automated pipelines that build projects or documents.
 #'
 #' @param dep_source_paths files to scan for project dependencies to write to the lock file.
+#'   Defaults to './packages.R`. See [capsule_sources()] for setting other defaults.
 #' @param lockfile_path output path for the lock file.
 #' @param minify a boolean value indicicating if lockfile JSON should have whitespace removed to shrink footprint.
 #'
 #' @return `lockfile_path`. Writes lockfile as a side effect.
 #' @export
 capshot <- function(
-  dep_source_paths = "./packages.R",
+  dep_source_paths = capsule_sources(),
   lockfile_path = "./renv.lock",
   minify = FALSE
 ) {
@@ -69,7 +70,7 @@ capshot <- function(
 
 #' @describeIn capshot a variation that returns lockfile json as a character vector for further use.
 #' @export
-capshot_str <- function(dep_source_paths = "./packages.R", minify = FALSE) {
+capshot_str <- function(dep_source_paths = capsule_sources(), minify = FALSE) {
   generate_lockfile_json(
     get_project_deps(detect_dependencies(dep_source_paths)),
     minify = minify
@@ -104,7 +105,7 @@ get_project_dcfs <- function(declared_deps, pkg_names, pkg_dcfs) {
     current_deps <- new_current_deps
   }
   missing <- setdiff(names(project_deps), unlist(pkg_names))
-  if (length(missing)) stop("Cannot complete capshot(). Project dependencies not installed locally: ", 
+  if (length(missing)) stop("Cannot complete capshot(). Project dependencies not installed locally: ",
   paste(missing, collapse = ", "), "\n\n",
   "Use dev_mirror_lockfile() to bring the local library up to at least the lockfile versions for all dependencies."
   )
diff --git a/R/capsule_sources.R b/R/capsule_sources.R
new file mode 100644
index 0000000..38167ca
--- /dev/null
+++ b/R/capsule_sources.R
@@ -0,0 +1,20 @@
+##' Get the default files from which to detect dependencies
+##'
+##' Dependencies to be encapsulated are detected from R files in your repository.
+##' A single `./packages.R` file is the default, but you can provide a
+##' vector of paths directly, using the R global option `capsule.sources`, or
+##' the environment variable `CAPSULE_SOURCES` (the latter takes only a single
+##' file name). Using a single file with all library() calls makes an explicit
+##' assertion of your dependencies. This way spurious usages of pkg:: for
+##' packages not stated as dependencies will cause errors that can be caught.
+##'
+##' @title capsule_sources
+##' @param paths The default files in which to look for dependencies
+##' @author Noam Ross
+##' @export
+capsule_sources <- function(paths = "./packages.R") {
+  getOption(
+    "capsule.sources",
+     default = Sys.getenv("CAPSULE_SOURCES", unset = paths)
+  )
+}
diff --git a/R/create.R b/R/create.R
index b08a369..1feb060 100644
--- a/R/create.R
+++ b/R/create.R
@@ -5,14 +5,15 @@
 ##' file that contains all library() calls - hence this makes an explicit
 ##' assertion of your dependencies. This way spurious usages of pkg:: for
 ##' packages not stated as dependencies will cause errors that can be caught.
-##' 
+##'
 ##' @title create
 ##' @param dep_source_paths files to find package dependencies in.
+##'    Defaults to './packages.R`. See [capsule_sources()] for setting other defaults.
 ##' @return nothing. Creates a capsule as a side effect.
 ##' @author Miles McBain
 ##' @export
 create <- function(
-  dep_source_paths = "./packages.R",
+  dep_source_paths = capsule_sources(),
   lockfile_path = "./renv.lock"
 ) {
 
diff --git a/R/recreate.R b/R/recreate.R
index 56806f3..1a168fd 100644
--- a/R/recreate.R
+++ b/R/recreate.R
@@ -7,15 +7,16 @@
 ##' Similarly to `create()`, you are expected to supply a vector of files in
 ##' your project to extract dependencies from. Things work best when this is a
 ##' single file containing only dependency related code.
-##' 
+##'
 ##' @title recreate
 ##' @param dep_source_paths a character vector of project source files to
-##'   extract dependencies from.
+##'   extract dependencies from.  Defaults to './packages.R`.
+##'   See [capsule_sources()] for setting other defaults.
 ##' @return nothing. The capsule is regenerated as a side effect.
 ##' @author Miles McBain
 ##' @seealso [create()]
 ##' @export
-recreate <- function(dep_source_paths = "./packages.R") {
+recreate <- function(dep_source_paths = capsule_sources()) {
 
   delete()
   create(dep_source_paths = dep_source_paths)
diff --git a/README.md b/README.md
index b368e85..5ea0786 100644
--- a/README.md
+++ b/README.md
@@ -60,7 +60,8 @@ The following package(s) will be updated in the lockfile:
 
 You supply a vector of file paths to extract dependencies from. The default is
 `"./packages.R"`. These dependencies are copied from your regular (dev) library
-to your local capsule.
+to your local capsule. These can also be set at the user or project level with
+`options(capsule.sources = <PATHS>)`, or a `CAPSULE_SOURCES` environment variable.
 
 Notice how this is easier when you keep your library calls all in one place? :wink:
 
diff --git a/man/capshot.Rd b/man/capshot.Rd
index 23001b2..2fc0d19 100644
--- a/man/capshot.Rd
+++ b/man/capshot.Rd
@@ -6,15 +6,16 @@
 \title{Quickly generate an renv compliant lock file}
 \usage{
 capshot(
-  dep_source_paths = "./packages.R",
+  dep_source_paths = capsule_sources(),
   lockfile_path = "./renv.lock",
   minify = FALSE
 )
 
-capshot_str(dep_source_paths = "./packages.R", minify = FALSE)
+capshot_str(dep_source_paths = capsule_sources(), minify = FALSE)
 }
 \arguments{
-\item{dep_source_paths}{files to scan for project dependencies to write to the lock file.}
+\item{dep_source_paths}{files to scan for project dependencies to write to the lock file.
+Defaults to './packages.R`. See \code{\link[=capsule_sources]{capsule_sources()}} for setting other defaults.}
 
 \item{lockfile_path}{output path for the lock file.}
 
@@ -39,6 +40,6 @@ be integrated into automated pipelines that build projects or documents.
 }
 \section{Functions}{
 \itemize{
-\item \code{capshot_str}: a variation that returns lockfile json as a character vector for further use.
-}}
+\item \code{capshot_str()}: a variation that returns lockfile json as a character vector for further use.
 
+}}
diff --git a/man/capsule_sources.Rd b/man/capsule_sources.Rd
new file mode 100644
index 0000000..7b1ab4c
--- /dev/null
+++ b/man/capsule_sources.Rd
@@ -0,0 +1,26 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/capsule_sources.R
+\name{capsule_sources}
+\alias{capsule_sources}
+\title{capsule_sources}
+\usage{
+capsule_sources(paths = "./packages.R")
+}
+\arguments{
+\item{paths}{The default files in which to look for dependencies}
+}
+\description{
+Get the default files from which to detect dependencies
+}
+\details{
+Dependencies to be encapsulated are detected from R files in your repository.
+A single \code{./packages.R} file is the default, but you can provide a
+vector of paths directly, using the R global option \code{capsule.sources}, or
+the environment variable \code{CAPSULE_SOURCES} (the latter takes only a single
+file name). Using a single file with all library() calls makes an explicit
+assertion of your dependencies. This way spurious usages of pkg:: for
+packages not stated as dependencies will cause errors that can be caught.
+}
+\author{
+Noam Ross
+}
diff --git a/man/compare_lockfile.Rd b/man/compare_lockfile.Rd
index cfd2b02..59d1caf 100644
--- a/man/compare_lockfile.Rd
+++ b/man/compare_lockfile.Rd
@@ -21,9 +21,9 @@ versions in the local R library (.libPaths()) or capsule library (./renv).
 }
 \section{Functions}{
 \itemize{
-\item \code{compare_capsule_to_lockfile}: compares the renv libray to the lockfile
-}}
+\item \code{compare_capsule_to_lockfile()}: compares the renv libray to the lockfile
 
+}}
 \seealso{
 Other comparisons: 
 \code{\link{any_local_behind_lockfile}()},
diff --git a/man/create.Rd b/man/create.Rd
index 58e9e14..2d91fd5 100644
--- a/man/create.Rd
+++ b/man/create.Rd
@@ -4,10 +4,11 @@
 \alias{create}
 \title{create}
 \usage{
-create(dep_source_paths = "./packages.R", lockfile_path = "./renv.lock")
+create(dep_source_paths = capsule_sources(), lockfile_path = "./renv.lock")
 }
 \arguments{
-\item{dep_source_paths}{files to find package dependencies in.}
+\item{dep_source_paths}{files to find package dependencies in.
+Defaults to './packages.R`. See \code{\link[=capsule_sources]{capsule_sources()}} for setting other defaults.}
 }
 \value{
 nothing. Creates a capsule as a side effect.
diff --git a/man/get_behind.Rd b/man/get_behind.Rd
index 7af0538..6717c87 100644
--- a/man/get_behind.Rd
+++ b/man/get_behind.Rd
@@ -41,9 +41,9 @@ same version but different SHAs.
 }
 \section{Functions}{
 \itemize{
-\item \code{get_capsule_behind_lockfile}: get packages in the renv library that are behind the lockfile
-}}
+\item \code{get_capsule_behind_lockfile()}: get packages in the renv library that are behind the lockfile
 
+}}
 \examples{
 \dontrun{
 get_local_behind_capsule(
diff --git a/man/recreate.Rd b/man/recreate.Rd
index 674f7f5..dfd8e9c 100644
--- a/man/recreate.Rd
+++ b/man/recreate.Rd
@@ -4,11 +4,12 @@
 \alias{recreate}
 \title{recreate}
 \usage{
-recreate(dep_source_paths = "./packages.R")
+recreate(dep_source_paths = capsule_sources())
 }
 \arguments{
 \item{dep_source_paths}{a character vector of project source files to
-extract dependencies from.}
+extract dependencies from.  Defaults to './packages.R`.
+See \code{\link[=capsule_sources]{capsule_sources()}} for setting other defaults.}
 }
 \value{
 nothing. The capsule is regenerated as a side effect.