diff --git a/.github/workflows/bench.yml b/.github/workflows/bench.yml
index 6279f5f578..ac2f026dab 100644
--- a/.github/workflows/bench.yml
+++ b/.github/workflows/bench.yml
@@ -91,7 +91,7 @@ jobs:
             flag: p
             device: cpu
             interface: none
-            build_script: ""
+            build_script: "bash .github/workflows/phoenix/build.sh cpu none"
           - cluster: phoenix
             name: Georgia Tech | Phoenix (NVHPC)
             group: phoenix
@@ -99,7 +99,7 @@ jobs:
             flag: p
             device: gpu
             interface: acc
-            build_script: ""
+            build_script: "bash .github/workflows/phoenix/build.sh gpu acc"
           - cluster: phoenix
             name: Georgia Tech | Phoenix (NVHPC)
             group: phoenix
@@ -107,7 +107,7 @@ jobs:
             flag: p
             device: gpu
             interface: omp
-            build_script: ""
+            build_script: "bash .github/workflows/phoenix/build.sh gpu omp"
           - cluster: frontier
             name: Oak Ridge | Frontier (CCE)
             group: phoenix
@@ -115,7 +115,7 @@ jobs:
             flag: f
             device: gpu
             interface: acc
-            build_script: "bash .github/workflows/frontier/build.sh gpu acc bench"
+            build_script: "bash .github/workflows/frontier/build.sh gpu acc"
           - cluster: frontier
             name: Oak Ridge | Frontier (CCE)
             group: phoenix
@@ -123,7 +123,7 @@ jobs:
             flag: f
             device: gpu
             interface: omp
-            build_script: "bash .github/workflows/frontier/build.sh gpu omp bench"
+            build_script: "bash .github/workflows/frontier/build.sh gpu omp"
           - cluster: frontier_amd
             name: Oak Ridge | Frontier (AMD)
             group: phoenix
@@ -131,7 +131,7 @@ jobs:
             flag: famd
             device: gpu
             interface: omp
-            build_script: "bash .github/workflows/frontier_amd/build.sh gpu omp bench"
+            build_script: "bash .github/workflows/frontier_amd/build.sh gpu omp"
     runs-on:
       group: ${{ matrix.group }}
       labels: ${{ matrix.labels }}
@@ -153,9 +153,8 @@ jobs:
           ref: master
           path: master
 
-      - name: Setup & Build
-        if: matrix.build_script != ''
-        run: | 
+      - name: Fetch Dependencies
+        run: |
           (cd pr     && ${{ matrix.build_script }}) &
           (cd master && ${{ matrix.build_script }}) &
           wait %1 && wait %2
diff --git a/.github/workflows/frontier/bench.sh b/.github/workflows/frontier/bench.sh
index 35b4c5950e..1aafa19e76 100644
--- a/.github/workflows/frontier/bench.sh
+++ b/.github/workflows/frontier/bench.sh
@@ -1,20 +1,50 @@
 #!/bin/bash
 
 n_ranks=12
+build_opts=""
 device_opts=""
 if [ "$job_device" = "gpu" ]; then
     gpus=$(rocm-smi --showid | awk '{print $1}' | grep -Eo '[0-9]+' | uniq | tr '\n' ' ')
     n_ranks=$(echo "$gpus" | wc -w)         # number of GPUs on node
     gpu_ids=$(echo "$gpus" | tr ' ' '\n' | tr '\n' ' ' | sed 's/ $//')  # GPU IDs from rocm-smi
-    device_opts+="--gpu"
+    build_opts+="--gpu"
     if [ "$job_interface" = "acc" ]; then
-        device_opts+=" acc"
+        build_opts+=" acc"
     elif [ "$job_interface" = "omp" ]; then
-        device_opts+=" mp"
+        build_opts+=" mp"
     fi
-    device_opts+=" -g $gpu_ids"
+    device_opts="$build_opts -g $gpu_ids"
 fi
 
+# Build case-optimized binaries on compute node (deps already fetched on login node)
+max_attempts=3
+attempt=1
+while [ $attempt -le $max_attempts ]; do
+    echo "Build attempt $attempt of $max_attempts..."
+    build_cmd_ok=true
+    for dir in benchmarks/*/; do
+        if ! ./mfc.sh run -v "$dir/case.py" --case-optimization -j 8 --dry-run $build_opts; then
+            build_cmd_ok=false
+            break
+        fi
+    done
+
+    if [ "$build_cmd_ok" = true ]; then
+        echo "Build succeeded on attempt $attempt."
+        break
+    fi
+
+    if [ $attempt -lt $max_attempts ]; then
+        echo "Build failed on attempt $attempt. Cleaning source targets and retrying in 30s..."
+        ./mfc.sh clean -t pre_process simulation post_process syscheck
+        sleep 30
+    else
+        echo "Build failed after $max_attempts attempts."
+        exit 1
+    fi
+    attempt=$((attempt + 1))
+done
+
 if [ "$job_device" = "gpu" ]; then
     ./mfc.sh bench --mem 12 -j $n_ranks -o "$job_slug.yaml" -- -c frontier $device_opts -n $n_ranks
 else
diff --git a/.github/workflows/frontier/build.sh b/.github/workflows/frontier/build.sh
index 18cddc96ca..84b67020ca 100644
--- a/.github/workflows/frontier/build.sh
+++ b/.github/workflows/frontier/build.sh
@@ -1,11 +1,13 @@
 #!/bin/bash
 
+# Fetch dependencies on login node (internet access).
+# Source code is built on compute nodes via test.sh / bench.sh.
+
 # Ignore SIGHUP to survive login node session drops
 trap '' HUP
 
 job_device=$1
 job_interface=$2
-run_bench=$3
 build_opts=""
 if [ "$job_device" = "gpu" ]; then
   build_opts+="--gpu"
@@ -18,39 +20,4 @@ fi
 
 . ./mfc.sh load -c f -m g
 
-max_attempts=3
-attempt=1
-while [ $attempt -le $max_attempts ]; do
-    echo "Build attempt $attempt of $max_attempts..."
-    if [ "$run_bench" == "bench" ]; then
-        build_cmd_ok=true
-        for dir in benchmarks/*/; do
-            dirname=$(basename "$dir")
-            if ! ./mfc.sh run -v "$dir/case.py" --case-optimization -j 8 --dry-run $build_opts; then
-                build_cmd_ok=false
-                break
-            fi
-        done
-    else
-        if ./mfc.sh test -v -a --dry-run --rdma-mpi -j 8 $build_opts; then
-            build_cmd_ok=true
-        else
-            build_cmd_ok=false
-        fi
-    fi
-
-    if [ "$build_cmd_ok" = true ]; then
-        echo "Build succeeded on attempt $attempt."
-        exit 0
-    fi
-
-    if [ $attempt -lt $max_attempts ]; then
-        echo "Build failed on attempt $attempt. Cleaning and retrying in 30s..."
-        ./mfc.sh clean
-        sleep 30
-    fi
-    attempt=$((attempt + 1))
-done
-
-echo "Build failed after $max_attempts attempts."
-exit 1
+./mfc.sh build --deps-only -j 8 $build_opts
diff --git a/.github/workflows/frontier/test.sh b/.github/workflows/frontier/test.sh
index 17fbbaf8e5..3240ced6b8 100644
--- a/.github/workflows/frontier/test.sh
+++ b/.github/workflows/frontier/test.sh
@@ -11,8 +11,32 @@ if [ "$job_device" = "gpu" ]; then
     elif [ "$job_interface" = "omp" ]; then
         device_opts+=" mp"
     fi
+else
+    device_opts+=" --no-gpu"
 fi
 
+# Build source code on compute node (deps already fetched on login node)
+max_attempts=3
+attempt=1
+while [ $attempt -le $max_attempts ]; do
+    echo "Build attempt $attempt of $max_attempts..."
+    if ./mfc.sh test -v -a --dry-run --rdma-mpi -j 8 $device_opts; then
+        echo "Build succeeded on attempt $attempt."
+        break
+    fi
+
+    if [ $attempt -lt $max_attempts ]; then
+        echo "Build failed on attempt $attempt. Cleaning source targets and retrying in 30s..."
+        ./mfc.sh clean -t pre_process simulation post_process syscheck
+        sleep 30
+    else
+        echo "Build failed after $max_attempts attempts."
+        exit 1
+    fi
+    attempt=$((attempt + 1))
+done
+
+# Run tests
 if [ "$job_device" = "gpu" ]; then
     ./mfc.sh test -v -a --rdma-mpi --max-attempts 3 -j $ngpus $device_opts -- -c frontier
 else
diff --git a/.github/workflows/frontier_amd/bench.sh b/.github/workflows/frontier_amd/bench.sh
index 6e01687e79..173251c679 100644
--- a/.github/workflows/frontier_amd/bench.sh
+++ b/.github/workflows/frontier_amd/bench.sh
@@ -1,20 +1,50 @@
 #!/bin/bash
 
 n_ranks=12
+build_opts=""
 device_opts=""
 if [ "$job_device" = "gpu" ]; then
     gpus=$(rocm-smi --showid | awk '{print $1}' | grep -Eo '[0-9]+' | uniq | tr '\n' ' ')
     n_ranks=$(echo "$gpus" | wc -w)         # number of GPUs on node
     gpu_ids=$(echo "$gpus" | tr ' ' '\n' | tr '\n' ' ' | sed 's/ $//')  # GPU IDs from rocm-smi
-    device_opts+="--gpu"
+    build_opts+="--gpu"
     if [ "$job_interface" = "acc" ]; then
-        device_opts+=" acc"
+        build_opts+=" acc"
     elif [ "$job_interface" = "omp" ]; then
-        device_opts+=" mp"
+        build_opts+=" mp"
     fi
-    device_opts+=" -g $gpu_ids"
+    device_opts="$build_opts -g $gpu_ids"
 fi
 
+# Build case-optimized binaries on compute node (deps already fetched on login node)
+max_attempts=3
+attempt=1
+while [ $attempt -le $max_attempts ]; do
+    echo "Build attempt $attempt of $max_attempts..."
+    build_cmd_ok=true
+    for dir in benchmarks/*/; do
+        if ! ./mfc.sh run -v "$dir/case.py" --case-optimization -j 8 --dry-run $build_opts; then
+            build_cmd_ok=false
+            break
+        fi
+    done
+
+    if [ "$build_cmd_ok" = true ]; then
+        echo "Build succeeded on attempt $attempt."
+        break
+    fi
+
+    if [ $attempt -lt $max_attempts ]; then
+        echo "Build failed on attempt $attempt. Cleaning source targets and retrying in 30s..."
+        ./mfc.sh clean -t pre_process simulation post_process syscheck
+        sleep 30
+    else
+        echo "Build failed after $max_attempts attempts."
+        exit 1
+    fi
+    attempt=$((attempt + 1))
+done
+
 if [ "$job_device" = "gpu" ]; then
     ./mfc.sh bench --mem 12 -j $n_ranks -o "$job_slug.yaml" -- -c frontier_amd $device_opts -n $n_ranks
 else
diff --git a/.github/workflows/frontier_amd/build.sh b/.github/workflows/frontier_amd/build.sh
index 56c47d8ff4..1b120ae6f7 100644
--- a/.github/workflows/frontier_amd/build.sh
+++ b/.github/workflows/frontier_amd/build.sh
@@ -1,11 +1,13 @@
 #!/bin/bash
 
+# Fetch dependencies on login node (internet access).
+# Source code is built on compute nodes via test.sh / bench.sh.
+
 # Ignore SIGHUP to survive login node session drops
 trap '' HUP
 
 job_device=$1
 job_interface=$2
-run_bench=$3
 build_opts=""
 if [ "$job_device" = "gpu" ]; then
   build_opts+="--gpu"
@@ -18,39 +20,4 @@ fi
 
 . ./mfc.sh load -c famd -m g
 
-max_attempts=3
-attempt=1
-while [ $attempt -le $max_attempts ]; do
-    echo "Build attempt $attempt of $max_attempts..."
-    if [ "$run_bench" == "bench" ]; then
-        build_cmd_ok=true
-        for dir in benchmarks/*/; do
-            dirname=$(basename "$dir")
-            if ! ./mfc.sh run -v "$dir/case.py" --case-optimization -j 8 --dry-run $build_opts; then
-                build_cmd_ok=false
-                break
-            fi
-        done
-    else
-        if ./mfc.sh test -v -a --dry-run -j 8 $build_opts; then
-            build_cmd_ok=true
-        else
-            build_cmd_ok=false
-        fi
-    fi
-
-    if [ "$build_cmd_ok" = true ]; then
-        echo "Build succeeded on attempt $attempt."
-        exit 0
-    fi
-
-    if [ $attempt -lt $max_attempts ]; then
-        echo "Build failed on attempt $attempt. Cleaning and retrying in 30s..."
-        ./mfc.sh clean
-        sleep 30
-    fi
-    attempt=$((attempt + 1))
-done
-
-echo "Build failed after $max_attempts attempts."
-exit 1
+./mfc.sh build --deps-only -j 8 $build_opts
diff --git a/.github/workflows/frontier_amd/test.sh b/.github/workflows/frontier_amd/test.sh
index ff65aa2b0e..afc944b8d3 100644
--- a/.github/workflows/frontier_amd/test.sh
+++ b/.github/workflows/frontier_amd/test.sh
@@ -11,8 +11,32 @@ if [ "$job_device" = "gpu" ]; then
     elif [ "$job_interface" = "omp" ]; then
         device_opts+=" mp"
     fi
+else
+    device_opts+=" --no-gpu"
 fi
 
+# Build source code on compute node (deps already fetched on login node)
+max_attempts=3
+attempt=1
+while [ $attempt -le $max_attempts ]; do
+    echo "Build attempt $attempt of $max_attempts..."
+    if ./mfc.sh test -v -a --dry-run -j 8 $device_opts; then
+        echo "Build succeeded on attempt $attempt."
+        break
+    fi
+
+    if [ $attempt -lt $max_attempts ]; then
+        echo "Build failed on attempt $attempt. Cleaning source targets and retrying in 30s..."
+        ./mfc.sh clean -t pre_process simulation post_process syscheck
+        sleep 30
+    else
+        echo "Build failed after $max_attempts attempts."
+        exit 1
+    fi
+    attempt=$((attempt + 1))
+done
+
+# Run tests
 if [ "$job_device" = "gpu" ]; then
     ./mfc.sh test -v -a --max-attempts 3 -j $ngpus $device_opts -- -c frontier_amd
 else
diff --git a/.github/workflows/phoenix/bench.sh b/.github/workflows/phoenix/bench.sh
index 447bd710d9..b3e26178b9 100644
--- a/.github/workflows/phoenix/bench.sh
+++ b/.github/workflows/phoenix/bench.sh
@@ -48,8 +48,8 @@ while [ $attempt -le $max_attempts ]; do
     fi
 
     if [ $attempt -lt $max_attempts ]; then
-        echo "Build failed on attempt $attempt. Cleaning and retrying in 30s..."
-        ./mfc.sh clean
+        echo "Build failed on attempt $attempt. Cleaning source targets and retrying in 30s..."
+        ./mfc.sh clean -t pre_process simulation post_process syscheck
         sleep 30
     else
         echo "Build failed after $max_attempts attempts."
diff --git a/.github/workflows/phoenix/build.sh b/.github/workflows/phoenix/build.sh
new file mode 100644
index 0000000000..8a850fca6f
--- /dev/null
+++ b/.github/workflows/phoenix/build.sh
@@ -0,0 +1,23 @@
+#!/bin/bash
+
+# Fetch dependencies on login node (internet access).
+# Source code is built on compute nodes via test.sh / bench.sh.
+
+# Ignore SIGHUP to survive login node session drops
+trap '' HUP
+
+job_device=$1
+job_interface=$2
+build_opts=""
+if [ "$job_device" = "gpu" ]; then
+  build_opts+="--gpu"
+  if [ "$job_interface" = "acc" ]; then
+      build_opts+=" acc"
+  elif [ "$job_interface" = "omp" ]; then
+      build_opts+=" mp"
+  fi
+fi
+
+. ./mfc.sh load -c p -m $job_device
+
+./mfc.sh build --deps-only -j $(nproc) $build_opts
diff --git a/.github/workflows/phoenix/test.sh b/.github/workflows/phoenix/test.sh
index 3920d96ed7..1706713df3 100644
--- a/.github/workflows/phoenix/test.sh
+++ b/.github/workflows/phoenix/test.sh
@@ -10,6 +10,7 @@ if [ "$job_device" = "gpu" ]; then
     fi
 fi
 
+# Build source code on compute node (deps already fetched on login node)
 max_attempts=3
 attempt=1
 while [ $attempt -le $max_attempts ]; do
@@ -20,8 +21,8 @@ while [ $attempt -le $max_attempts ]; do
     fi
 
     if [ $attempt -lt $max_attempts ]; then
-        echo "Build failed on attempt $attempt. Cleaning and retrying in 30s..."
-        ./mfc.sh clean
+        echo "Build failed on attempt $attempt. Cleaning source targets and retrying in 30s..."
+        ./mfc.sh clean -t pre_process simulation post_process syscheck
         sleep 30
     else
         echo "Build failed after $max_attempts attempts."
@@ -37,6 +38,8 @@ if [ "$job_device" = "gpu" ]; then
     gpu_ids=$(seq -s ' ' 0 $(($gpu_count-1))) # 0,1,2,...,gpu_count-1
     device_opts="-g $gpu_ids"
     n_test_threads=`expr $gpu_count \* 2`
+else
+    device_opts="--no-gpu"
 fi
 
 ./mfc.sh test -v --max-attempts 3 -a -j $n_test_threads $device_opts -- -c phoenix
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 0be51076ec..d79e61fecd 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -149,7 +149,7 @@ jobs:
     strategy:
       matrix:
         include:
-          # Phoenix (GT) — build+test combined in SLURM job
+          # Phoenix (GT) — deps on login node, build+test in SLURM job
           - runner:       'gt'
             cluster:      'phoenix'
             cluster_name: 'Georgia Tech | Phoenix'
@@ -165,7 +165,7 @@ jobs:
             cluster_name: 'Georgia Tech | Phoenix'
             device: 'cpu'
             interface: 'none'
-          # Frontier (ORNL) — build on login node, test via SLURM
+          # Frontier (ORNL) — deps on login node, build+test via SLURM
           - runner:       'frontier'
             cluster:      'frontier'
             cluster_name: 'Oak Ridge | Frontier'
@@ -181,7 +181,7 @@ jobs:
             cluster_name: 'Oak Ridge | Frontier'
             device: 'cpu'
             interface: 'none'
-          # Frontier AMD — build on login node, test via SLURM
+          # Frontier AMD — deps on login node, build+test via SLURM
           - runner:       'frontier'
             cluster:      'frontier_amd'
             cluster_name: 'Oak Ridge | Frontier (AMD)'
@@ -203,11 +203,10 @@ jobs:
       - name: Clone
         uses: actions/checkout@v4
 
-      - name: Build
-        if:   matrix.cluster != 'phoenix'
+      - name: Fetch Dependencies
         run:  bash .github/workflows/${{ matrix.cluster }}/build.sh ${{ matrix.device }} ${{ matrix.interface }}
 
-      - name: Test
+      - name: Build & Test
         run:  bash .github/workflows/${{ matrix.cluster }}/submit.sh .github/workflows/${{ matrix.cluster }}/test.sh ${{ matrix.device }} ${{ matrix.interface }}
 
       - name: Print Logs
diff --git a/toolchain/mfc/build.py b/toolchain/mfc/build.py
index 6430f7ad35..eca3a4f2c0 100644
--- a/toolchain/mfc/build.py
+++ b/toolchain/mfc/build.py
@@ -566,6 +566,12 @@ def __build_target(target: typing.Union[MFCTarget, str], case: input.MFCInputFil
 
     history.add(target.name)
 
+    # Dependencies are pinned to fixed versions. If already configured
+    # (built & installed by a prior --deps-only step), skip entirely
+    # to avoid re-entering the superbuild (which may access the network).
+    if target.isDependency and target.is_configured(case) and os.path.isdir(target.get_install_dirpath(case)):
+        return
+
     for dep in target.requires.compute():
         # If we have already built and installed this target,
         # do not do so again. This can be inferred by whether
@@ -611,6 +617,29 @@ def build(targets = None, case: input.MFCInputFile = None, history: typing.Set[s
     case    = case or input.load(ARG("input"), ARG("--"), {})
     case.validate_params()
 
+    if ARG("deps_only", False):
+        all_deps = set()
+        for target in targets:
+            if target.isDependency:
+                all_deps.add(target)
+            for dep in target.requires.compute():
+                all_deps.add(dep)
+
+        sorted_deps = sorted(all_deps, key=lambda t: t.name)
+
+        if len(history) == 0:
+            cons.print(f"[bold]Fetch Dependencies | {format_list_to_string([d.name for d in sorted_deps], 'magenta', 'None')}[/bold]")
+            cons.print(no_indent=True)
+
+        if not sorted_deps:
+            cons.print("[yellow]No dependencies to build for the requested targets.[/yellow]")
+            return
+
+        for dep in sorted_deps:
+            __build_target(dep, case, history)
+
+        return
+
     if len(history) == 0:
         cons.print(__generate_header(case, targets))
         cons.print(no_indent=True)
diff --git a/toolchain/mfc/cli/commands.py b/toolchain/mfc/cli/commands.py
index 8ad8c4bd07..bb9fddb76d 100644
--- a/toolchain/mfc/cli/commands.py
+++ b/toolchain/mfc/cli/commands.py
@@ -154,6 +154,13 @@
             default=False,
             dest="case_optimization",
         ),
+        Argument(
+            name="deps-only",
+            help="Only fetch and build dependencies, do not build MFC targets.",
+            action=ArgAction.STORE_TRUE,
+            default=False,
+            dest="deps_only",
+        ),
     ],
     examples=[
         Example("./mfc.sh build", "Build all default targets (CPU)"),