diff --git a/.github/workflows/rust-ci.yml b/.github/workflows/rust-ci.yml
index 1af0bf2f4ae..2140bd11f1e 100644
--- a/.github/workflows/rust-ci.yml
+++ b/.github/workflows/rust-ci.yml
@@ -62,6 +62,13 @@ jobs:
       - uses: dtolnay/rust-toolchain@1.90
         with:
           components: rustfmt
+      - uses: Swatinem/rust-cache@v2
+        with:
+          # This workflow runs from the repo root, but the Rust workspace lives in codex-rs.
+          workspaces: |
+            codex-rs
+          cache-targets: true
+          cache-on-failure: true
       - name: cargo fmt
         run: cargo fmt -- --config imports_granularity=Item --check
       - name: Verify codegen for mcp-types
@@ -78,6 +85,12 @@ jobs:
     steps:
       - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@1.90
+      - uses: Swatinem/rust-cache@v2
+        with:
+          workspaces: |
+            codex-rs
+          cache-targets: true
+          cache-on-failure: true
       - uses: taiki-e/install-action@44c6d64aa62cd779e873306675c7a58e86d6d532 # v2
         with:
           tool: cargo-shear
@@ -97,10 +110,8 @@ jobs:
       run:
         working-directory: codex-rs
     env:
-      # Speed up repeated builds across CI runs by caching compiled objects (non-Windows).
-      USE_SCCACHE: ${{ startsWith(matrix.runner, 'windows') && 'false' || 'true' }}
       CARGO_INCREMENTAL: "0"
-      SCCACHE_CACHE_SIZE: 10G
+      CARGO_TARGET_DIR: ${{ github.workspace }}/.target/${{ matrix.target }}-${{ matrix.profile }}
 
     strategy:
       fail-fast: false
@@ -155,68 +166,6 @@ jobs:
           targets: ${{ matrix.target }}
           components: clippy
 
-      - name: Compute lockfile hash
-        id: lockhash
-        working-directory: codex-rs
-        shell: bash
-        run: |
-          set -euo pipefail
-          echo "hash=$(sha256sum Cargo.lock | cut -d' ' -f1)" >> "$GITHUB_OUTPUT"
-          echo "toolchain_hash=$(sha256sum rust-toolchain.toml | cut -d' ' -f1)" >> "$GITHUB_OUTPUT"
-
-      # Explicit cache restore: split cargo home vs target, so we can
-      # avoid caching the large target dir on the gnu-dev job.
-      - name: Restore cargo home cache
-        id: cache_cargo_home_restore
-        uses: actions/cache/restore@v5
-        with:
-          path: |
-            ~/.cargo/bin/
-            ~/.cargo/registry/index/
-            ~/.cargo/registry/cache/
-            ~/.cargo/git/db/
-          key: cargo-home-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-${{ steps.lockhash.outputs.toolchain_hash }}
-          restore-keys: |
-            cargo-home-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-
-
-      # Install and restore sccache cache
-      - name: Install sccache
-        if: ${{ env.USE_SCCACHE == 'true' }}
-        uses: taiki-e/install-action@44c6d64aa62cd779e873306675c7a58e86d6d532 # v2
-        with:
-          tool: sccache
-          version: 0.7.5
-
-      - name: Configure sccache backend
-        if: ${{ env.USE_SCCACHE == 'true' }}
-        shell: bash
-        run: |
-          set -euo pipefail
-          if [[ -n "${ACTIONS_CACHE_URL:-}" && -n "${ACTIONS_RUNTIME_TOKEN:-}" ]]; then
-            echo "SCCACHE_GHA_ENABLED=true" >> "$GITHUB_ENV"
-            echo "Using sccache GitHub backend"
-          else
-            echo "SCCACHE_GHA_ENABLED=false" >> "$GITHUB_ENV"
-            echo "SCCACHE_DIR=${{ github.workspace }}/.sccache" >> "$GITHUB_ENV"
-            echo "Using sccache local disk + actions/cache fallback"
-          fi
-
-      - name: Enable sccache wrapper
-        if: ${{ env.USE_SCCACHE == 'true' }}
-        shell: bash
-        run: echo "RUSTC_WRAPPER=sccache" >> "$GITHUB_ENV"
-
-      - name: Restore sccache cache (fallback)
-        if: ${{ env.USE_SCCACHE == 'true' && env.SCCACHE_GHA_ENABLED != 'true' }}
-        id: cache_sccache_restore
-        uses: actions/cache/restore@v5
-        with:
-          path: ${{ github.workspace }}/.sccache/
-          key: sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-${{ github.run_id }}
-          restore-keys: |
-            sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-
-            sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-
-
       - if: ${{ matrix.target == 'x86_64-unknown-linux-musl' || matrix.target == 'aarch64-unknown-linux-musl'}}
         name: Prepare APT cache directories (musl)
         shell: bash
@@ -244,6 +193,33 @@ jobs:
           sudo apt-get -y update -o Acquire::Retries=3
           sudo apt-get -y install --no-install-recommends musl-tools pkg-config
 
+      - uses: Swatinem/rust-cache@v2
+        with:
+          # Cache registry/git and build artifacts for this workspace/target/profile triple.
+          workspaces: |
+            codex-rs
+          shared-key: rust-ci-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}
+          cache-targets: true
+          cache-on-failure: true
+
+      - name: Install cargo-chef
+        uses: taiki-e/install-action@44c6d64aa62cd779e873306675c7a58e86d6d532 # v2
+        with:
+          tool: cargo-chef
+          version: 0.1.71
+
+      - name: Pre-warm dependency cache (cargo-chef)
+        shell: bash
+        run: |
+          set -euo pipefail
+          RECIPE="${RUNNER_TEMP}/chef-recipe.json"
+          cargo chef prepare --recipe-path "$RECIPE"
+          PROFILE_ARGS="--profile ${{ matrix.profile }}"
+          if [[ "${{ matrix.profile }}" == "release" ]]; then
+            PROFILE_ARGS="--release"
+          fi
+          cargo chef cook --recipe-path "$RECIPE" --target ${{ matrix.target }} $PROFILE_ARGS --all-features
+
       - name: Install cargo-chef
         if: ${{ matrix.profile == 'release' }}
         uses: taiki-e/install-action@44c6d64aa62cd779e873306675c7a58e86d6d532 # v2
@@ -277,45 +253,6 @@ jobs:
           find . -name Cargo.toml -mindepth 2 -maxdepth 2 -print0 \
             | xargs -0 -n1 -I{} bash -c 'cd "$(dirname "{}")" && cargo check --profile ${{ matrix.profile }}'
 
-      # Save caches explicitly; make non-fatal so cache packaging
-      # never fails the overall job. Only save when key wasn't hit.
-      - name: Save cargo home cache
-        if: always() && !cancelled() && steps.cache_cargo_home_restore.outputs.cache-hit != 'true'
-        continue-on-error: true
-        uses: actions/cache/save@v5
-        with:
-          path: |
-            ~/.cargo/bin/
-            ~/.cargo/registry/index/
-            ~/.cargo/registry/cache/
-            ~/.cargo/git/db/
-          key: cargo-home-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-${{ steps.lockhash.outputs.toolchain_hash }}
-
-      - name: Save sccache cache (fallback)
-        if: always() && !cancelled() && env.USE_SCCACHE == 'true' && env.SCCACHE_GHA_ENABLED != 'true'
-        continue-on-error: true
-        uses: actions/cache/save@v5
-        with:
-          path: ${{ github.workspace }}/.sccache/
-          key: sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-${{ github.run_id }}
-
-      - name: sccache stats
-        if: always() && env.USE_SCCACHE == 'true'
-        continue-on-error: true
-        run: sccache --show-stats || true
-
-      - name: sccache summary
-        if: always() && env.USE_SCCACHE == 'true'
-        shell: bash
-        run: |
-          {
-            echo "### sccache stats — ${{ matrix.target }} (${{ matrix.profile }})";
-            echo;
-            echo '```';
-            sccache --show-stats || true;
-            echo '```';
-          } >> "$GITHUB_STEP_SUMMARY"
-
       - name: Save APT cache (musl)
         if: always() && !cancelled() && (matrix.target == 'x86_64-unknown-linux-musl' || matrix.target == 'aarch64-unknown-linux-musl') && steps.cache_apt_restore.outputs.cache-hit != 'true'
         continue-on-error: true
@@ -344,10 +281,8 @@ jobs:
       run:
         working-directory: codex-rs
     env:
-      # Speed up repeated builds across CI runs by caching compiled objects (non-Windows).
-      USE_SCCACHE: ${{ startsWith(matrix.runner, 'windows') && 'false' || 'true' }}
       CARGO_INCREMENTAL: "0"
-      SCCACHE_CACHE_SIZE: 10G
+      CARGO_TARGET_DIR: ${{ github.workspace }}/.target/${{ matrix.target }}-${{ matrix.profile }}
 
     strategy:
       fail-fast: false
@@ -396,64 +331,13 @@ jobs:
         with:
           targets: ${{ matrix.target }}
 
-      - name: Compute lockfile hash
-        id: lockhash
-        working-directory: codex-rs
-        shell: bash
-        run: |
-          set -euo pipefail
-          echo "hash=$(sha256sum Cargo.lock | cut -d' ' -f1)" >> "$GITHUB_OUTPUT"
-          echo "toolchain_hash=$(sha256sum rust-toolchain.toml | cut -d' ' -f1)" >> "$GITHUB_OUTPUT"
-
-      - name: Restore cargo home cache
-        id: cache_cargo_home_restore
-        uses: actions/cache/restore@v5
-        with:
-          path: |
-            ~/.cargo/bin/
-            ~/.cargo/registry/index/
-            ~/.cargo/registry/cache/
-            ~/.cargo/git/db/
-          key: cargo-home-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-${{ steps.lockhash.outputs.toolchain_hash }}
-          restore-keys: |
-            cargo-home-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-
-
-      - name: Install sccache
-        if: ${{ env.USE_SCCACHE == 'true' }}
-        uses: taiki-e/install-action@44c6d64aa62cd779e873306675c7a58e86d6d532 # v2
-        with:
-          tool: sccache
-          version: 0.7.5
-
-      - name: Configure sccache backend
-        if: ${{ env.USE_SCCACHE == 'true' }}
-        shell: bash
-        run: |
-          set -euo pipefail
-          if [[ -n "${ACTIONS_CACHE_URL:-}" && -n "${ACTIONS_RUNTIME_TOKEN:-}" ]]; then
-            echo "SCCACHE_GHA_ENABLED=true" >> "$GITHUB_ENV"
-            echo "Using sccache GitHub backend"
-          else
-            echo "SCCACHE_GHA_ENABLED=false" >> "$GITHUB_ENV"
-            echo "SCCACHE_DIR=${{ github.workspace }}/.sccache" >> "$GITHUB_ENV"
-            echo "Using sccache local disk + actions/cache fallback"
-          fi
-
-      - name: Enable sccache wrapper
-        if: ${{ env.USE_SCCACHE == 'true' }}
-        shell: bash
-        run: echo "RUSTC_WRAPPER=sccache" >> "$GITHUB_ENV"
-
-      - name: Restore sccache cache (fallback)
-        if: ${{ env.USE_SCCACHE == 'true' && env.SCCACHE_GHA_ENABLED != 'true' }}
-        id: cache_sccache_restore
-        uses: actions/cache/restore@v5
+      - uses: Swatinem/rust-cache@v2
         with:
-          path: ${{ github.workspace }}/.sccache/
-          key: sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-${{ github.run_id }}
-          restore-keys: |
-            sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-
-            sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-
+          workspaces: |
+            codex-rs
+          shared-key: rust-ci-tests-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}
+          cache-targets: true
+          cache-on-failure: true
 
       - uses: taiki-e/install-action@44c6d64aa62cd779e873306675c7a58e86d6d532 # v2
         with:
@@ -467,43 +351,6 @@ jobs:
           RUST_BACKTRACE: 1
           NEXTEST_STATUS_LEVEL: leak
 
-      - name: Save cargo home cache
-        if: always() && !cancelled() && steps.cache_cargo_home_restore.outputs.cache-hit != 'true'
-        continue-on-error: true
-        uses: actions/cache/save@v5
-        with:
-          path: |
-            ~/.cargo/bin/
-            ~/.cargo/registry/index/
-            ~/.cargo/registry/cache/
-            ~/.cargo/git/db/
-          key: cargo-home-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-${{ steps.lockhash.outputs.toolchain_hash }}
-
-      - name: Save sccache cache (fallback)
-        if: always() && !cancelled() && env.USE_SCCACHE == 'true' && env.SCCACHE_GHA_ENABLED != 'true'
-        continue-on-error: true
-        uses: actions/cache/save@v5
-        with:
-          path: ${{ github.workspace }}/.sccache/
-          key: sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-${{ github.run_id }}
-
-      - name: sccache stats
-        if: always() && env.USE_SCCACHE == 'true'
-        continue-on-error: true
-        run: sccache --show-stats || true
-
-      - name: sccache summary
-        if: always() && env.USE_SCCACHE == 'true'
-        shell: bash
-        run: |
-          {
-            echo "### sccache stats — ${{ matrix.target }} (tests)";
-            echo;
-            echo '```';
-            sccache --show-stats || true;
-            echo '```';
-          } >> "$GITHUB_STEP_SUMMARY"
-
       - name: verify tests passed
         if: steps.test.outcome == 'failure'
         run: |
@@ -537,8 +384,3 @@ jobs:
           [[ '${{ needs.cargo_shear.result }}' == 'success' ]] || { echo 'cargo_shear failed'; exit 1; }
           [[ '${{ needs.lint_build.result }}' == 'success' ]] || { echo 'lint_build failed'; exit 1; }
           [[ '${{ needs.tests.result }}' == 'success' ]] || { echo 'tests failed'; exit 1; }
-
-      - name: sccache summary note
-        if: always()
-        run: |
-          echo "Per-job sccache stats are attached to each matrix job's Step Summary."