diff --git a/BirdFlowAPI.tar.gz b/BirdFlowAPI.tar.gz
deleted file mode 100644
index 0331378..0000000
Binary files a/BirdFlowAPI.tar.gz and /dev/null differ
diff --git a/NAMESPACE b/NAMESPACE
index 4e0e672..fc4818b 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -5,4 +5,3 @@ export(load_models)
 export(range_rescale)
 export(save_json_palette)
 export(symbolize_raster_data)
-import(BirdFlowR)
diff --git a/R/flow.R b/R/flow.R
index 2b81f7b..3a339ee 100644
--- a/R/flow.R
+++ b/R/flow.R
@@ -22,7 +22,6 @@ get_s3_config <- function() {
 
 #' Null coalescing operator for config values
 `%||%` <- function(a, b) if (!is.null(a) && !is.na(a) && nzchar(a)) a else b
-#' @import BirdFlowR
 
 if(FALSE) {
    # Manually set function arguments for dev and debugging
@@ -35,12 +34,6 @@ if(FALSE) {
    # the other files are correct
 
 
-   # Load required libraries
-   library(BirdFlowR)
-   library(jsonlite)
-   library(terra)
-   library(aws.s3)
-
    # Load globals and helpers
    original_wd <- getwd()
    if(!grepl("api$", getwd()))
@@ -99,6 +92,11 @@ save_local_path <- "config/save_local.flag"
 #'    `type`
 #' @export
 flow <- function(loc, week, taxa, n, direction = "forward", save_local = FALSE) {
+  # TODO:
+  # utils::data("species", package = "BirdFlowAPI", envir = environment())
+
+  # load_models()
+
   s3_cfg <- get_s3_config()
   s3_enabled <- !is.na(s3_cfg$bucket) && nzchar(s3_cfg$bucket)
 
@@ -139,24 +137,24 @@ flow <- function(loc, week, taxa, n, direction = "forward", save_local = FALSE)
 
   # Snap lat/lon to cell center using the first model (all models use same grid)
   bf <- models[[ifelse(taxa == "total", species$species[1], taxa)]]
-  xy <- latlon_to_xy(lat_lon$lat, lat_lon$lon, bf = bf)
-  col <- x_to_col(xy$x, bf = bf)
-  row <- y_to_row(xy$y, bf = bf)
-  x <- col_to_x(col, bf = bf)
-  y <- row_to_y(row, bf = bf)
-  snapped_latlon <- xy_to_latlon(x, y, bf = bf)
+  xy <- BirdFlowR::latlon_to_xy(lat_lon$lat, lat_lon$lon, bf = bf)
+  col <- BirdFlowR::x_to_col(xy$x, bf = bf)
+  row <- BirdFlowR::y_to_row(xy$y, bf = bf)
+  x <- BirdFlowR::col_to_x(col, bf = bf)
+  y <- BirdFlowR::row_to_y(row, bf = bf)
+  snapped_latlon <- BirdFlowR::xy_to_latlon(x, y, bf = bf)
   snapped_latlon$lat <- round(snapped_latlon$lat, 2)
   snapped_latlon$lon <- round(snapped_latlon$lon, 2)
   lat_lon <- snapped_latlon
 
   # Re-compute snapped xy for later use
-  xy <- latlon_to_xy(lat_lon$lat, lat_lon$lon, bf = bf)
+  xy <- BirdFlowR::latlon_to_xy(lat_lon$lat, lat_lon$lon, bf = bf)
 
   # Form file names and S3 keys using snapped lat/lon
   snapped_lat <- paste(lat_lon$lat, collapse = "_")
   snapped_lon <- paste(lat_lon$lon, collapse = "_")
   cache_prefix <- paste0(direction, "/", taxa, "_", week, "_", snapped_lat, "_", snapped_lon, "/")
-  pred_weeks <- lookup_timestep_sequence(bf, start = week, n = n, direction = direction)
+  pred_weeks <- BirdFlowR::lookup_timestep_sequence(bf, start = week, n = n, direction = direction)
   png_files <- paste0(flow_type, "_", taxa, "_", pred_weeks, ".png")
   symbology_files <- paste0(flow_type, "_", taxa, "_", pred_weeks, ".json")
   png_bucket_paths <- paste0(s3_flow_path, cache_prefix, png_files)
@@ -169,14 +167,14 @@ flow <- function(loc, week, taxa, n, direction = "forward", save_local = FALSE)
   cache_hit <- TRUE
   if (!save_local && s3_enabled) {
     for (i in seq_along(pred_weeks)) {
-      png_exists <- object_exists(object = png_bucket_paths[i], bucket = s3_cfg$bucket)
-      json_exists <- object_exists(object = symbology_bucket_paths[i], bucket = s3_cfg$bucket)
+      png_exists <- aws.s3::object_exists(object = png_bucket_paths[i], bucket = s3_cfg$bucket)
+      json_exists <- aws.s3::object_exists(object = symbology_bucket_paths[i], bucket = s3_cfg$bucket)
       if (!png_exists || !json_exists) {
         cache_hit <- FALSE
         break
       }
     }
-    tiff_exists <- object_exists(object = tiff_bucket_path, bucket = s3_cfg$bucket)
+    tiff_exists <- aws.s3::object_exists(object = tiff_bucket_path, bucket = s3_cfg$bucket)
     if (!tiff_exists) cache_hit <- FALSE
   } else {
     # Local cache: check if all files exist in localtmp
@@ -231,23 +229,23 @@ flow <- function(loc, week, taxa, n, direction = "forward", save_local = FALSE)
   for (i in seq_along(target_species)) {
     sp <- target_species[i]
     bf <- models[[sp]]
-    valid <- is_location_valid(bf, timestep = week, x = xy$x, y = xy$y)
+    valid <- BirdFlowR::is_location_valid(bf, timestep = week, x = xy$x, y = xy$y)
     if (!all(valid)) {
       next
     }
     any_valid <- TRUE
-    start_distr <- as_distr(xy, bf)
+    start_distr <- BirdFlowR::as_distr(xy, bf)
     if (nrow(lat_lon) > 1) {
       start_distr <- apply(start_distr, 1, sum)
       start_distr <- start_distr / sum(start_distr)
     }
     log_progress(paste("Starting prediction for", sp))
     pred <- predict(bf, start_distr, start = week, n = n, direction = direction)
-    location_i <- xy_to_i(xy, bf = bf)
-    initial_population_distr <- get_distr(bf, which = week)
+    location_i <- BirdFlowR::xy_to_i(xy, bf = bf)
+    initial_population_distr <- BirdFlowR::get_distr(bf, which = week)
     start_proportion <- sum(initial_population_distr[location_i]) / 1
-    abundance <- pred * species$population[species$species == sp] / prod(res(bf) / 1000) * start_proportion
-    this_raster <- rasterize_distr(abundance, bf = bf, format = "terra")
+    abundance <- pred * species$population[species$species == sp] / prod(terra::res(bf) / 1000) * start_proportion
+    this_raster <- BirdFlowR::rasterize_distr(abundance, bf = bf, format = "terra")
     if (is.null(combined)) {
       combined <- this_raster
     } else {
diff --git a/R/load_models.R b/R/load_models.R
index d9df9e9..b28729f 100644
--- a/R/load_models.R
+++ b/R/load_models.R
@@ -15,6 +15,8 @@
 #'
 #' @export
 load_models <- function() {
+    # utils::data("species", package = "BirdFlowAPI", envir = environment())
+
     # Load BirdFlow models
     BirdFlowR::birdflow_options(collection_url = "https://birdflow-science.s3.amazonaws.com/sparse_avian_flu/")
     index <- BirdFlowR::load_collection_index()
@@ -23,14 +25,16 @@ load_models <- function() {
         stop("Expected BirdFlow models:", paste(miss, collapse = ", "), " are missing from the model collection." )
     }
 
-    # This is slow so skipping if it's already done - useful when developing to 
-    # avoid having to wait to reload. 
-    if(!exists("models") || !is.environment(models) || !all(species$species %in% names(models))) {
-        models <<- new.env(parent = globalenv())
-        print(paste("Loading", length(species$species), "models from https://birdflow-science.s3.amazonaws.com/avian_flu/"))
+    # This is slow so skipping if it's already done - useful when developing to
+    # avoid having to wait to reload.
+    if(!all(species$species %in% names(models))) {
+        print(paste("Loading", length(species$species), "models from https://birdflow-science.s3.amazonaws.com/sparse_avian_flu/"))
         for (sp in species$species) {
             print(paste0("Loading model for species: ", sp))
             models[[sp]] <- BirdFlowR::load_model(model = sp)
         }
     }
-}
\ No newline at end of file
+    else {
+        print("Models already loaded.")
+    }
+}
diff --git a/R/models.R b/R/models.R
new file mode 100644
index 0000000..865143f
--- /dev/null
+++ b/R/models.R
@@ -0,0 +1 @@
+models <- new.env()
diff --git a/R/zzz.R b/R/zzz.R
index 2b09801..c27bd5b 100644
--- a/R/zzz.R
+++ b/R/zzz.R
@@ -1,9 +1,3 @@
-.onLoad <- function(libname, pkgname) {
-    utils::data("species", package = "BirdFlowAPI", envir = parent.env(environment()))
-    utils::data("flow_colors", package = "BirdFlowAPI", envir = parent.env(environment()))
-    load_models()
-}
-
 .ignore_unused_imports <- function() {
     plumber::plumb
 }
\ No newline at end of file
diff --git a/README.md b/README.md
index f85073d..8f57d27 100644
--- a/README.md
+++ b/README.md
@@ -6,15 +6,10 @@ BirdFlowAPI is an R package containing the API and backend code for the Avian In
 
 You can build and install BirdFlowAPI locally or from GitHub.
 
-**Build locally:**
-```sh
-R CMD build .
-```
-This will create a source tarball (e.g., `BirdFlowAPI_x.y.z.tar.gz`).
 
-**Install from local tarball:**
+**Install from local cloned repository:**
 ```r
-install.packages("path/to/BirdFlowAPI_x.y.z.tar.gz", repos = NULL, type = "source")
+devtools::install()
 ```
 
 **Install from GitHub:**
@@ -22,6 +17,10 @@ install.packages("path/to/BirdFlowAPI_x.y.z.tar.gz", repos = NULL, type = "sourc
 devtools::install_github("UMassCDS/BirdFlowAPI")
 ```
 
+## Configure API
+
+The `load_models.R` file defines a function `load_models` that loads the the models of all species. The `load_models` function must be explicitly called while configuring the API. This is done by running `load_models()`.
+
 ## Testing
 
 Run the full test suite:
diff --git a/inst/plumber/flow/endpoints/predict.R b/inst/plumber/flow/endpoints/predict.R
index 6d59958..5ec5927 100644
--- a/inst/plumber/flow/endpoints/predict.R
+++ b/inst/plumber/flow/endpoints/predict.R
@@ -1,4 +1,3 @@
-library(BirdFlowR)
 birdflow_options(collection_url = "https://birdflow-science.s3.amazonaws.com/avian_flu/")
 
 #* Test and generate a plot from a BirdFlow model
@@ -27,4 +26,4 @@ function(model_name = "ambduc") {
     file_exists = file_exists,
     file_size = file_size
   )
-}
\ No newline at end of file
+}
diff --git a/man/flow.Rd b/man/flow.Rd
index 6fc4cb9..07605d4 100644
--- a/man/flow.Rd
+++ b/man/flow.Rd
@@ -4,7 +4,7 @@
 \alias{flow}
 \title{Implement inflow and outflow}
 \usage{
-flow(loc, week, taxa, n, direction = "forward", save_local = SAVE_LOCAL)
+flow(loc, week, taxa, n, direction = "forward", save_local = FALSE)
 }
 \arguments{
 \item{loc}{One or more locations as a scalar character each location should
@@ -21,7 +21,7 @@ the initial week so will have n + 1 images)}
 
 \item{direction}{Which direction to project in "backward" for inflow or "forward" for outflow"}
 
-\item{save_local}{True/False boolean flag - determines whether to copy files to AWS S3 bucket}
+\item{save_local}{True/False boolean flag - determines whether to save results locally (default: value in config/save_local.flag, or FALSE if not present). If FALSE, results are uploaded to S3 if configured.}
 }
 \value{
 A list with components:
@@ -36,6 +36,7 @@ A list with components:
 \code{week}
 \code{url}
 \code{legend}
+\code{type}
 }
 \description{
 This function is the heart of the inflow and outflow api and does all
diff --git a/man/get_s3_config.Rd b/man/get_s3_config.Rd
new file mode 100644
index 0000000..71b2e21
--- /dev/null
+++ b/man/get_s3_config.Rd
@@ -0,0 +1,11 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/flow.R
+\name{get_s3_config}
+\alias{get_s3_config}
+\title{Get S3 configuration from explicit config, environment variables, or IAM role}
+\usage{
+get_s3_config()
+}
+\description{
+Get S3 configuration from explicit config, environment variables, or IAM role
+}
diff --git a/man/grapes-or-or-grapes.Rd b/man/grapes-or-or-grapes.Rd
new file mode 100644
index 0000000..6c41ad5
--- /dev/null
+++ b/man/grapes-or-or-grapes.Rd
@@ -0,0 +1,11 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/flow.R
+\name{\%||\%}
+\alias{\%||\%}
+\title{Null coalescing operator for config values}
+\usage{
+a \%||\% b
+}
+\description{
+Null coalescing operator for config values
+}
diff --git a/man/set_s3_config.Rd b/man/set_s3_config.Rd
new file mode 100644
index 0000000..c97a5e1
--- /dev/null
+++ b/man/set_s3_config.Rd
@@ -0,0 +1,16 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/flow.R
+\name{set_s3_config}
+\alias{set_s3_config}
+\title{Set S3 configuration explicitly}
+\usage{
+set_s3_config(
+  access_key = NULL,
+  secret_key = NULL,
+  region = NULL,
+  bucket = NULL
+)
+}
+\description{
+Allows user to set S3 credentials and bucket at runtime. If not set, environment variables or IAM role will be used.
+}
diff --git a/tests/testthat/setup.R b/tests/testthat/setup.R
new file mode 100644
index 0000000..d6b67ae
--- /dev/null
+++ b/tests/testthat/setup.R
@@ -0,0 +1 @@
+load_models()
\ No newline at end of file