diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
new file mode 100644
index 0000000..9a1cb41
--- /dev/null
+++ b/.devcontainer/devcontainer.json
@@ -0,0 +1,15 @@
+{
+  "name": "FIMS Memory Benchmarks",
+  "image": "ghcr.io/rocker-org/devcontainer/r-ver:4.3",
+  "features": {
+    "ghcr.io/rocker-org/devcontainer-features/apt-packages:1": {
+      "packages": "g++,gcc,libelf-dev,libunwind-dev,libcap2-bin,make,gdb,valgrind",
+      "updatePackages": true
+    },
+    "ghcr.io/rocker-org/devcontainer-features/r-packages:1": {
+      "packages": "covr,dplyr,devtools,ggplot2,graphics,methods,Rcpp,RcppEigen,scales,snowfall,TMB,tibble,tidyr,usethis",
+      "installSystemRequirements": true
+    }
+  },
+  "postCreateCommand": "bash .devcontainer/postCreate.sh"
+}
diff --git a/.devcontainer/postCreate.sh b/.devcontainer/postCreate.sh
new file mode 100755
index 0000000..3922fa5
--- /dev/null
+++ b/.devcontainer/postCreate.sh
@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+mkdir -p "$HOME/.R"
+MAKEVARS="$HOME/.R/Makevars"
+
+touch "$MAKEVARS"
+
+add_line_if_missing() {
+  local line="$1"
+  if ! grep -Fqx "$line" "$MAKEVARS"; then
+    printf '%s\n' "$line" >> "$MAKEVARS"
+  fi
+}
+
+add_line_if_missing "PKG_CXXFLAGS += -g -O0 -fno-omit-frame-pointer -fvisibility=default"
+add_line_if_missing "PKG_STRIP = true"
+
+echo "Configured $MAKEVARS for debug builds."
diff --git a/R/main.R b/R/main.R
new file mode 100644
index 0000000..e469b87
--- /dev/null
+++ b/R/main.R
@@ -0,0 +1,12 @@
+source("R/setup_FIMS")
+
+run_branch_benchmark <- function(ref) {
+  install_fims_debug(ref)
+  source("R/run_benchmark.R")
+}
+
+# 1. Benchmark Main
+run_branch_benchmark("main") # Outputs to outputs/massif_main.out
+
+# 2. Benchmark Feature Branch
+run_branch_benchmark("xptr-refactor") # Outputs to outputs/massif_xptr.out
diff --git a/R/run_benchmark.R b/R/run_benchmark.R
new file mode 100644
index 0000000..e69de29
diff --git a/R/setup_FIMS b/R/setup_FIMS
new file mode 100644
index 0000000..9b5794a
--- /dev/null
+++ b/R/setup_FIMS
@@ -0,0 +1,20 @@
+#' Install a specific FIMS branch compiled in Debug Mode
+#'
+#' @param ref Branch name, tag, or commit hash (e.g. "main", "xptr-refactor")
+install_fims_debug <- function(ref = "main") {
+  message(sprintf("Installing NOAA-FIMS/FIMS@%s in debug mode...", ref))
+
+  # Ensure remotes is available
+  if (!requireNamespace("remotes", quietly = TRUE)) {
+    install.packages("remotes")
+  }
+
+  # Force compilation from source with user's ~/.R/Makevars applied
+  remotes::install_github(
+    repo = "NOAA-FIMS/FIMS",
+    ref = ref,
+    force = TRUE,
+    build_vignettes = FALSE,
+    INSTALL_opts = c("--no-multiarch")
+  )
+}
diff --git a/README.md b/README.md
index cf3205a..7d2addf 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,54 @@
 # FIMSMemoryBenchmarks
-A repo to compare and keep track of FIMS memory footprint 
+
+A repository to benchmark and compare the memory footprint of NOAA-FIMS/FIMS builds.
+
+## Repository Layout
+
+- `/R`: Helper R scripts for setup and benchmark stage execution.
+- `/scripts`: Shell runners for memory profiling tools.
+- `/outputs`: Benchmark and profiler outputs (`.gitkeep` included).
+- `/.devcontainer`: Codespaces setup for debug-safe R compilation flags.
+
+## Debug Build Configuration in Codespaces
+
+This repository includes `.devcontainer/postCreate.sh`, which configures `~/.R/Makevars` with:
+
+- `PKG_CXXFLAGS += -g -O0 -fno-omit-frame-pointer -fvisibility=default`
+- `PKG_STRIP = true`
+
+These settings preserve symbols and frame pointers for profiler-friendly builds.
+
+## Install FIMS in Debug Mode
+
+`R/setup_FIMS` provides:
+
+```r
+install_fims_debug(ref = "main")
+```
+
+It installs `NOAA-FIMS/FIMS` from GitHub for a chosen branch/tag/commit using source compilation.
+
+## Benchmark Stages
+
+`R/run_benchmark.R` is structured into five stages:
+
+1. Static model construction through `MakeADFun()`
+2. Single evaluation calls (`obj$fn()` and `obj$gr()`)
+3. Full optimization run with `nlminb` (without `sdreport`)
+4. Full optimization run with `nlminb` and `sdreport`
+5. Cleanup and retention check via `TMB::FreeADFun(obj)` and `gc()`
+
+> Before sourcing `R/run_benchmark.R`, define `fims_stage1_builder()` so it returns the stage-1 `MakeADFun()` object.
+
+## Run Massif Benchmarks
+
+```bash
+bash scripts/run_massif.sh
+```
+
+This generates:
+
+- `outputs/massif_main.out`
+- `outputs/massif_xptr.out`
+
+Use `ms_print` to inspect each output file.
diff --git a/outputs/.gitkeep b/outputs/.gitkeep
new file mode 100644
index 0000000..e69de29
diff --git a/scripts/run_massif.sh b/scripts/run_massif.sh
new file mode 100755
index 0000000..7a7c046
--- /dev/null
+++ b/scripts/run_massif.sh
@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+OUTPUT_DIR="$REPO_ROOT/outputs"
+
+mkdir -p "$OUTPUT_DIR"
+
+run_ref() {
+  local ref="$1"
+  local out_file="$2"
+
+  valgrind --tool=massif \
+    --massif-out-file="$out_file" \
+    Rscript -e "source('R/setup_FIMS'); install_fims_debug('$ref'); source('R/run_benchmark.R')"
+}
+
+run_ref "main" "$OUTPUT_DIR/massif_main.out"
+run_ref "xptr-refactor" "$OUTPUT_DIR/massif_xptr.out"
+
+echo "Massif outputs written to $OUTPUT_DIR"
+echo "  - $OUTPUT_DIR/massif_main.out"
+echo "  - $OUTPUT_DIR/massif_xptr.out"