Add a script that generates a Rust test to check re-exports

diff --git a/.github/workflows/README.md b/.github/workflows/README.md
index a1d7e431..a7b54d00 100644
--- a/.github/workflows/README.md
+++ b/.github/workflows/README.md
@@ -30,6 +30,7 @@ Run from rust.yml unless stated otherwise. Unfortunately we are now exceeding th
 16. `Kani`
 17. `API`
 18. `Policy` - enforce repository coding policy.
-19. `release` - run by `release.yml`
-20. `labeler` - run by `manage-pr.yml`
-21. `Shellcheck` - run by `shellcheck.yml`
+19. `Re-exports`
+20. `release` - run by `release.yml`
+21. `labeler` - run by `manage-pr.yml`
+22. `Shellcheck` - run by `shellcheck.yml`
diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 7323aed0..7727417b 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -345,3 +345,16 @@ jobs:
         uses: dtolnay/rust-toolchain@stable
       - name: "Run policy script"
         run: ./contrib/check-for-policy-violations.sh
+
+  Re-exports:
+    name: Check re-exports - stable toolchain
+    runs-on: ubuntu-24.04
+    strategy:
+      fail-fast: false
+    steps:
+      - name: "Checkout repo"
+        uses: actions/checkout@v4
+      - name: "Select toolchain"
+        uses: dtolnay/rust-toolchain@stable
+      - name: "Run API checker script"
+        run: contrib/generate-re-export-test.sh && cd ./primitives && cargo test --all-features
diff --git a/contrib/generate-re-export-test.sh b/contrib/generate-re-export-test.sh
new file mode 100755
index 00000000..555a8afd
--- /dev/null
+++ b/contrib/generate-re-export-test.sh
@@ -0,0 +1,170 @@
+#!/usr/bin/env bash
+#
+# Script for generating a Rust test file that verifies all bitcoin_units items
+# are re-exported in bitcoin_primitives.
+#
+# The script parses api/units/all-features.txt and generates use statements
+# that will fail to compile if any re-exports are missing.
+
+set -euo pipefail
+
+api_file="./api/units/all-features.txt"
+output_file="./primitives/tests/check-re-exports.rs"
+
+usage() {
+    cat <<EOF
+Usage:
+
+    ./generate-re-export-test.sh
+
+DESCRIPTION
+  Generates a Rust test file that verifies all public types and modules from
+  bitcoin_units are re-exported in bitcoin_primitives.
+
+  The script parses api/units/all-features.txt and creates use statements for
+  every 'pub enum', 'pub struct', and 'pub mod' declaration.
+
+  Output file: primitives/tests/check-re-exports.rs
+EOF
+}
+
+main() {
+    while [[ $# -gt 0 ]]; do
+        case $1 in
+            -h|--help)
+                usage
+                exit 0
+                ;;
+            *)
+                say_err "unknown option: $1"
+                usage
+                exit 1
+                ;;
+        esac
+    done
+
+    check_required_commands
+    check_required_files
+
+    say "Parsing $api_file and generating Rust test..."
+
+    generate_test_file
+
+    say "Generated $output_file"
+    say "Run 'cd primitives && cargo test --all-features check_all_bitcoin_units_items_are_reexported' to test"
+}
+
+generate_test_file() {
+    local temp_file;
+    temp_file=$(mktemp)
+
+    # Generate the file header
+    cat > "$temp_file" <<'EOF'
+// SPDX-License-Identifier: CC0-1.0
+
+//! Test that all public types and modules from bitcoin_units are re-exported in bitcoin_primitives.
+//!
+//! This test is automatically generated by contrib/generate-re-export-test.sh
+//! Any compilation error indicates a missing re-export.
+
+#![allow(dead_code)]
+#![allow(unused_imports)]
+// No benefit in running this test without features enabled.
+#[cfg(not(feature = "alloc"))]
+compile_error!("alloc feature needs to be enabled");
+#[cfg(not(feature = "hex"))]
+compile_error!("hex feature needs to be enabled");
+#[cfg(not(feature = "arbitrary"))]
+compile_error!("arbitrary feature needs to be enabled");
+
+#[test]
+fn check_all_bitcoin_units_items_are_reexported() {
+    // This test will fail to compile if any bitcoin_units item is not re-exported in bitcoin_primitives
+
+EOF
+
+    # Extract and convert all pub items
+    local use_statements=()
+    local seen_items=()
+
+    while IFS= read -r line; do
+        local path=""
+
+        # Extract pub enum
+        if [[ "$line" =~ pub\ enum\ (bitcoin_units::[^[:space:]]+) ]]; then
+            path="${BASH_REMATCH[1]}"
+        # Extract pub struct
+        elif [[ "$line" =~ pub\ struct\ (bitcoin_units::[^[:space:]\(]+) ]]; then
+            path="${BASH_REMATCH[1]}"
+        # Extract pub mod
+        elif [[ "$line" =~ ^pub\ mod\ (bitcoin_units::[^[:space:]]+)$ ]]; then
+            path="${BASH_REMATCH[1]}"
+        fi
+
+        if [[ -n "$path" ]]; then
+            # Remove generic type parameters (e.g., <T>)
+            path="${path%%<*}"
+
+            # Convert bitcoin_units:: to bitcoin_primitives::
+            local primitives_path="${path//bitcoin_units::/bitcoin_primitives::}"
+
+            # Skip if we've already seen this item
+            if [[ " ${seen_items[*]} " != *" $primitives_path "* ]]; then
+                seen_items+=("$primitives_path")
+                use_statements+=("    use $primitives_path as _;")
+            fi
+        fi
+    done < "$api_file"
+
+    # Sort use statements and add to file
+    printf '%s\n' "${use_statements[@]}" | sort >> "$temp_file"
+
+    # Add closing brace
+    echo "}" >> "$temp_file"
+
+    # Move temp file to final location
+    mv "$temp_file" "$output_file"
+}
+
+check_required_files() {
+    if [[ ! -f "$api_file" ]]; then
+        err "Required file not found: $api_file"
+    fi
+
+    local output_dir
+    output_dir=$(dirname "$output_file")
+    if [[ ! -d "$output_dir" ]]; then
+        err "Output directory not found: $output_dir"
+    fi
+}
+
+check_required_commands() {
+    need_cmd grep
+    need_cmd sort
+    need_cmd mktemp
+}
+
+say() {
+    echo "generate-re-export-test: $1"
+}
+
+say_err() {
+    say "$1" >&2
+}
+
+err() {
+    echo "$1" >&2
+    exit 1
+}
+
+need_cmd() {
+    if ! command -v "$1" > /dev/null 2>&1
+    then err "need '$1' (command not found)"
+    fi
+}
+
+#
+# Main script
+#
+main "$@"
+exit 0