diff --git a/.github/workflows/e2e.yml b/.github/workflows/e2e.yml
index 28ee123..9b042ec 100644
--- a/.github/workflows/e2e.yml
+++ b/.github/workflows/e2e.yml
@@ -3,10 +3,6 @@ name: E2E Tests
 on:
   workflow_dispatch:
     inputs:
-      release_tag:
-        description: 'GitHub release tag to test (e.g., v0.4.2)'
-        required: true
-        type: string
       test_channel:
         description: 'TX3 channel to test'
         required: false
@@ -16,278 +12,63 @@ on:
         - stable
         - nightly
         - beta
+  pull_request:
+    branches:
+      - main
 
 env:
   CARGO_TERM_COLOR: always
 
 jobs:
-  # Download tx3up binaries from GitHub releases
-  download-binaries:
-    name: Download tx3up (${{ matrix.os }}-${{ matrix.arch }})
-    runs-on: ubuntu-latest
-    
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          # Ubuntu Intel
-          - os: ubuntu
-            arch: intel
-            asset_pattern: "*x86_64-unknown-linux-gnu*"
-            artifact_name: tx3up-ubuntu-intel
-          
-          # Ubuntu ARM
-          - os: ubuntu
-            arch: arm
-            asset_pattern: "*aarch64-unknown-linux-gnu*"
-            artifact_name: tx3up-ubuntu-arm
-          
-          # macOS Intel
-          - os: mac
-            arch: intel
-            asset_pattern: "*x86_64-apple-darwin*"
-            artifact_name: tx3up-mac-intel
-          
-          # macOS ARM
-          - os: mac
-            arch: arm
-            asset_pattern: "*aarch64-apple-darwin*"
-            artifact_name: tx3up-mac-arm
-    
-    steps:
-    - name: Download release asset
-      env:
-        GH_TOKEN: ${{ github.token }}
-      run: |
-        echo "Downloading tx3up ${{ inputs.release_tag }} for ${{ matrix.os }}-${{ matrix.arch }}"
-        
-        # Create target directory
-        mkdir -p target/release
-        
-        # List available assets first
-        echo "Available assets for ${{ inputs.release_tag }}:"
-        gh release view ${{ inputs.release_tag }} --repo ${{ github.repository }} --json assets --jq '.assets[].name'
-        
-        # Download the asset using GitHub CLI
-        echo "Downloading assets matching pattern: ${{ matrix.asset_pattern }}"
-        gh release download ${{ inputs.release_tag }} \
-          --repo ${{ github.repository }} \
-          --pattern "${{ matrix.asset_pattern }}" \
-          --dir target/release/
-        
-        # List what was downloaded
-        echo "Downloaded files:"
-        ls -la target/release/
-        
-        # Find the downloaded file and extract if it's an archive
-        downloaded_file=$(find target/release -type f \( -name "*.tar.gz" -o -name "*.tar.xz" -o -name "*.zip" -o -name "*${{ matrix.os }}*${{ matrix.arch }}*" -o -name "*$(echo "${{ matrix.asset_pattern }}" | tr -d '*')*" \) | head -1)
-        
-        if [[ -z "$downloaded_file" ]]; then
-          echo "Error: No suitable file found for ${{ matrix.os }}-${{ matrix.arch }}"
-          echo "Available files:"
-          ls -la target/release/
-          exit 1
-        fi
-        
-        echo "Processing file: $downloaded_file"
-        
-        # Extract archives or handle direct binaries
-        if [[ "$downloaded_file" == *.tar.gz ]]; then
-          echo "Extracting tar.gz archive..."
-          tar -xzf "$downloaded_file" -C target/release/
-          rm "$downloaded_file"
-        elif [[ "$downloaded_file" == *.tar.xz ]]; then
-          echo "Extracting tar.xz archive..."
-          tar -xJf "$downloaded_file" -C target/release/
-          rm "$downloaded_file"
-        elif [[ "$downloaded_file" == *.zip ]]; then
-          echo "Extracting zip archive..."
-          unzip "$downloaded_file" -d target/release/
-          rm "$downloaded_file"
-        else
-          echo "File appears to be a direct binary"
-        fi
-        
-        # Find the tx3up binary
-        tx3up_binary=$(find target/release -name "tx3up" -type f -executable 2>/dev/null | head -1)
-        if [[ -z "$tx3up_binary" ]]; then
-          # Try without executable check (some extracted files might not have exec bit set)
-          tx3up_binary=$(find target/release -name "tx3up" -type f | head -1)
-        fi
-        
-        if [[ -z "$tx3up_binary" ]]; then
-          echo "Error: tx3up binary not found after extraction"
-          echo "Contents after extraction/download:"
-          find target/release -type f -exec ls -la {} \;
-          exit 1
-        fi
-        
-        echo "Found tx3up binary at: $tx3up_binary"
-        
-        # Move binary to standard location and make executable
-        if [[ "$tx3up_binary" != "target/release/tx3up" ]]; then
-          mv "$tx3up_binary" target/release/tx3up
-        fi
-        chmod +x target/release/tx3up
-        
-        echo "Successfully prepared tx3up binary"
-    
-    - name: Verify binary
-      run: |
-        ls -la target/release/tx3up
-        file target/release/tx3up
-        ./target/release/tx3up --version || echo "Version check failed, but binary exists"
-    
-    - name: Upload binary artifact
-      uses: actions/upload-artifact@v4
-      with:
-        name: ${{ matrix.artifact_name }}
-        path: target/release/tx3up
-        retention-days: 1
-    
-  # Run E2E tests using the downloaded binaries
   e2e-tests:
-    name: E2E Tests (${{ matrix.os }}-${{ matrix.arch }}, ${{ matrix.test }})
+    name: E2E (${{ matrix.runner }}, ${{ matrix.test }})
     runs-on: ${{ matrix.runner }}
-    needs: download-binaries
-    
+
     strategy:
       fail-fast: false
       matrix:
-        include:
-          # Ubuntu Intel tests
-          - os: ubuntu
-            arch: intel
-            runner: ubuntu-latest
-            artifact_name: tx3up-ubuntu-intel
-            test: fresh_install
-          - os: ubuntu
-            arch: intel
-            runner: ubuntu-latest
-            artifact_name: tx3up-ubuntu-intel
-            test: update_install
-          
-          # Ubuntu ARM tests
-          - os: ubuntu
-            arch: arm
-            runner: ubuntu-latest
-            artifact_name: tx3up-ubuntu-arm
-            test: fresh_install
-          - os: ubuntu
-            arch: arm
-            runner: ubuntu-latest
-            artifact_name: tx3up-ubuntu-arm
-            test: update_install
-          
-          # macOS Intel tests
-          - os: mac
-            arch: intel
-            runner: macos-13
-            artifact_name: tx3up-mac-intel
-            test: fresh_install
-          - os: mac
-            arch: intel
-            runner: macos-13
-            artifact_name: tx3up-mac-intel
-            test: update_install
-          
-          # macOS ARM tests
-          - os: mac
-            arch: arm
-            runner: macos-latest
-            artifact_name: tx3up-mac-arm
-            test: fresh_install
-          - os: mac
-            arch: arm
-            runner: macos-latest
-            artifact_name: tx3up-mac-arm
-            test: update_install
-    
+        runner:
+          - ubuntu-latest
+          - ubuntu-24.04-arm
+          - macos-latest
+        test:
+          - fresh_install
+          - update_install
+
     steps:
     - name: Checkout code
       uses: actions/checkout@v4
-    
-    - name: Download tx3up binary
-      uses: actions/download-artifact@v4
-      with:
-        name: ${{ matrix.artifact_name }}
-        path: target/release/
-    
-    - name: Make binary executable
-      run: chmod +x target/release/tx3up
-    
-    - name: Verify binary
-      run: |
-        ls -la target/release/tx3up
-        file target/release/tx3up
-    
-    - name: Install jq (for JSON validation)
+
+    - name: Install Rust toolchain
+      uses: dtolnay/rust-toolchain@stable
+
+    - name: Cache cargo build
+      uses: Swatinem/rust-cache@v2
+
+    - name: Build tx3up
+      run: cargo build --release
+
+    - name: Install jq
       run: |
-        if [[ "${{ matrix.os }}" == "ubuntu" ]]; then
+        if [[ "$RUNNER_OS" == "Linux" ]]; then
           sudo apt-get update && sudo apt-get install -y jq
-        elif [[ "${{ matrix.os }}" == "mac" ]]; then
-          brew install jq
+        elif [[ "$RUNNER_OS" == "macOS" ]]; then
+          command -v jq >/dev/null 2>&1 || brew install jq
         fi
-    
+
     - name: Run E2E test - ${{ matrix.test }}
-      run: |
-        echo "Running ${{ matrix.test }} test on ${{ matrix.os }}-${{ matrix.arch }}"
-        echo "Testing release: ${{ inputs.release_tag }}"
-        echo "Testing channel: ${{ inputs.test_channel }}"
-        ./tests/e2e/${{ matrix.test }}.sh
       env:
-        # Use a unique root directory for each test run
-        TX3_ROOT: ${{ github.workspace }}/test-root-${{ matrix.os }}-${{ matrix.arch }}-${{ matrix.test }}
-        TX3_CHANNEL: ${{ inputs.test_channel }}
-    
+        TX3_CHANNEL: ${{ inputs.test_channel || 'stable' }}
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      run: ./tests/e2e/${{ matrix.test }}.sh
+
     - name: Upload test artifacts on failure
       if: failure()
       uses: actions/upload-artifact@v4
       with:
-        name: test-artifacts-${{ matrix.os }}-${{ matrix.arch }}-${{ matrix.test }}
+        name: test-artifacts-${{ matrix.runner }}-${{ matrix.test }}
         path: |
-          ${{ github.workspace }}/test-root-*/
+          /tmp/tmp.*/tx3_test/
           target/release/tx3up
         retention-days: 7
-    
-    - name: Display test summary
-      if: always()
-      run: |
-        echo "## E2E Test Summary" >> $GITHUB_STEP_SUMMARY
-        echo "- **Release**: ${{ inputs.release_tag }}" >> $GITHUB_STEP_SUMMARY
-        echo "- **OS**: ${{ matrix.os }}" >> $GITHUB_STEP_SUMMARY
-        echo "- **Architecture**: ${{ matrix.arch }}" >> $GITHUB_STEP_SUMMARY
-        echo "- **Test**: ${{ matrix.test }}" >> $GITHUB_STEP_SUMMARY
-        echo "- **Channel**: ${{ inputs.test_channel }}" >> $GITHUB_STEP_SUMMARY
-        echo "- **Runner**: ${{ matrix.runner }}" >> $GITHUB_STEP_SUMMARY
-        if [[ "${{ job.status }}" == "success" ]]; then
-          echo "- **Result**: ✅ PASSED" >> $GITHUB_STEP_SUMMARY
-        else
-          echo "- **Result**: ❌ FAILED" >> $GITHUB_STEP_SUMMARY
-        fi
-
-  # Summary job that depends on all matrix jobs
-  e2e-summary:
-    name: E2E Tests Summary
-    runs-on: ubuntu-latest
-    needs: [download-binaries, e2e-tests]
-    if: always()
-    
-    steps:
-    - name: Check test results
-      run: |
-        echo "## Overall E2E Test Results" >> $GITHUB_STEP_SUMMARY
-        echo "**Tested Release**: ${{ inputs.release_tag }}" >> $GITHUB_STEP_SUMMARY
-        echo "**Tested Channel**: ${{ inputs.test_channel }}" >> $GITHUB_STEP_SUMMARY
-        echo "" >> $GITHUB_STEP_SUMMARY
-        if [[ "${{ needs.e2e-tests.result }}" == "success" ]]; then
-          echo "🎉 All E2E tests passed!" >> $GITHUB_STEP_SUMMARY
-          echo "📦 Downloaded binaries for all platforms successfully" >> $GITHUB_STEP_SUMMARY
-          exit 0
-        else
-          echo "❌ Some tests failed. Check individual job results for details." >> $GITHUB_STEP_SUMMARY
-          if [[ "${{ needs.download-binaries.result }}" != "success" ]]; then
-            echo "📥 Binary download stage failed" >> $GITHUB_STEP_SUMMARY
-          fi
-          exit 1
-        fi
\ No newline at end of file
+        if-no-files-found: ignore
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..d6abe6e
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,15 @@
+# Contributing to tx3up
+
+Thanks for your interest in contributing!
+
+## Before pushing
+
+Run the end-to-end install tests locally before pushing any change that could affect the install flow:
+
+```sh
+cargo build --release
+./tests/e2e/fresh_install.sh
+./tests/e2e/update_install.sh
+```
+
+These are the same scripts CI runs against your pull request. Catching failures locally is much faster than waiting for the matrix in `.github/workflows/e2e.yml` to complete. See [`tests/e2e/README.md`](tests/e2e/README.md) for details on what each script checks and how to run them against a non-default channel.
diff --git a/tests/e2e/README.md b/tests/e2e/README.md
new file mode 100644
index 0000000..3027519
--- /dev/null
+++ b/tests/e2e/README.md
@@ -0,0 +1,40 @@
+# tx3up E2E tests
+
+End-to-end tests for `tx3up`. They drive a real `tx3up` binary against a temporary `TX3_ROOT` and assert the resulting toolchain layout.
+
+## Tests
+
+- `fresh_install.sh` — runs `tx3up` against an empty root and verifies the channel directory, `manifest.json`, and at least one executable in `bin/` are created.
+- `update_install.sh` — installs once, runs `tx3up` again, and checks that the manifest is refreshed, no binaries are lost, and a third run is idempotent.
+
+Both scripts read `TX3_CHANNEL` from the environment (default: `stable`). They allocate their own `TX3_ROOT` via `mktemp -d` and clean it up on exit, so they will not touch your real `~/.tx3`.
+
+## Running locally
+
+From the repo root:
+
+```sh
+cargo build --release
+./tests/e2e/fresh_install.sh
+./tests/e2e/update_install.sh
+```
+
+To exercise a non-default channel:
+
+```sh
+TX3_CHANNEL=nightly ./tests/e2e/fresh_install.sh
+```
+
+Requirements: a working Rust toolchain and `jq` (the scripts fall back to a basic JSON check if `jq` is missing, but installing it is recommended). The scripts hit the real `tx3-lang/toolchain` GitHub releases, so the host needs network access. If you run into GitHub rate limits, export `GITHUB_TOKEN` before running.
+
+## How CI uses these tests
+
+`.github/workflows/e2e.yml` runs both scripts on every pull request to `main` and on manual `workflow_dispatch`. The workflow:
+
+1. Checks out the PR.
+2. Builds `tx3up` from source with `cargo build --release` on each runner.
+3. Runs `fresh_install.sh` and `update_install.sh` against the freshly-built binary.
+
+The matrix covers `ubuntu-latest`, `ubuntu-24.04-arm`, and `macos-latest`, with each script as a separate cell so failures are isolated. `workflow_dispatch` accepts a `test_channel` input (`stable`/`nightly`/`beta`); PR runs always use `stable`.
+
+Because CI builds from the PR's source, these tests gate the **current** code — not a previously-released binary.
diff --git a/tests/e2e/fresh_install.sh b/tests/e2e/fresh_install.sh
index 8969f79..4d1ff6d 100755
--- a/tests/e2e/fresh_install.sh
+++ b/tests/e2e/fresh_install.sh
@@ -113,7 +113,7 @@ main() {
     find "$TX3_ROOT" -type f -exec ls -la {} \; 2>/dev/null || true
     
     # Check if at least one binary was installed
-    bin_count=$(find "$TX3_ROOT/$TX3_CHANNEL/bin" -type f -executable 2>/dev/null | wc -l)
+    bin_count=$(find "$TX3_ROOT/$TX3_CHANNEL/bin" -type f -perm -u+x 2>/dev/null | wc -l)
     if [[ $bin_count -gt 0 ]]; then
         echo -e "${GREEN}✓ Found $bin_count executable binaries in bin directory${NC}"
     else
diff --git a/tests/e2e/update_install.sh b/tests/e2e/update_install.sh
index 3784144..e2c7c5d 100755
--- a/tests/e2e/update_install.sh
+++ b/tests/e2e/update_install.sh
@@ -181,7 +181,7 @@ main() {
     fi
     
     # Verify that at least some binaries are still executable
-    executable_count=$(find "$TX3_ROOT/$TX3_CHANNEL/bin" -type f -executable 2>/dev/null | wc -l)
+    executable_count=$(find "$TX3_ROOT/$TX3_CHANNEL/bin" -type f -perm -u+x 2>/dev/null | wc -l)
     if [[ $executable_count -gt 0 ]]; then
         echo -e "${GREEN}✓ Found $executable_count executable binaries after update${NC}"
     else