feat: Add semantic versioning and proper export of koalabear fields

.github/workflows/auto-release.yml

@@ -0,0 +1,160 @@
+name: Auto Release on Release Branch
+
+on:
+  pull_request:
+    types: [closed]
+    branches:
+      - release
+
+permissions:
+  contents: write
+
+jobs:
+  auto-release:
+    # Only run if PR was merged to release branch (not just closed)
+    if: github.event.pull_request.merged == true
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0  # Fetch all history for versioning
+
+      - name: Setup Zig
+        uses: goto-bus-stop/setup-zig@v2
+        with:
+          version: 0.14.1
+
+      - name: Read VERSION file
+        id: get_version
+        run: |
+          VERSION=$(cat VERSION)
+          echo "version=$VERSION" >> $GITHUB_OUTPUT
+          echo "tag=v$VERSION" >> $GITHUB_OUTPUT
+
+      - name: Check if tag exists
+        id: check_tag
+        run: |
+          if git rev-parse "v${{ steps.get_version.outputs.version }}" >/dev/null 2>&1; then
+            echo "exists=true" >> $GITHUB_OUTPUT
+            echo "⚠️ Tag v${{ steps.get_version.outputs.version }} already exists"
+          else
+            echo "exists=false" >> $GITHUB_OUTPUT
+            echo "✅ Tag v${{ steps.get_version.outputs.version }} does not exist"
+          fi
+
+      - name: Run tests
+        if: steps.check_tag.outputs.exists == 'false'
+        run: zig build test
+
+      - name: Build library
+        if: steps.check_tag.outputs.exists == 'false'
+        run: zig build
+
+      - name: Update build.zig.zon version
+        if: steps.check_tag.outputs.exists == 'false'
+        run: |
+          VERSION="${{ steps.get_version.outputs.version }}"
+          sed -i "s/\.version = \".*\"/\.version = \"$VERSION\"/" build.zig.zon
+
+      - name: Generate changelog
+        if: steps.check_tag.outputs.exists == 'false'
+        id: changelog
+        run: |
+          VERSION="${{ steps.get_version.outputs.version }}"
+
+          # Get previous tag
+          PREV_TAG=$(git describe --tags --abbrev=0 2>/dev/null || echo "")
+
+          if [ -z "$PREV_TAG" ]; then
+            echo "## 🎉 Initial Release" > CHANGELOG.md
+            echo "" >> CHANGELOG.md
+            echo "First release of zig-poseidon - A Zig implementation of Poseidon2 hash function." >> CHANGELOG.md
+            echo "" >> CHANGELOG.md
+            echo "### Features" >> CHANGELOG.md
+            echo "- BabyBear field (p = 2³¹ - 2²⁷ + 1) for Ethereum Lean chain" >> CHANGELOG.md
+            echo "- KoalaBear field (p = 2³¹ - 2²⁴ + 1) for plonky3 and Rust hash-sig compatibility" >> CHANGELOG.md
+            echo "- Generic Montgomery form implementation" >> CHANGELOG.md
+            echo "- Compression mode for Merkle Trees" >> CHANGELOG.md
+            echo "- Comprehensive test suite" >> CHANGELOG.md
+          else
+            echo "## Changes since $PREV_TAG" > CHANGELOG.md
+            echo "" >> CHANGELOG.md
+            git log "$PREV_TAG"..HEAD --pretty=format:"- %s (%h)" >> CHANGELOG.md
+          fi
+
+          cat CHANGELOG.md
+
+      - name: Create Git tag
+        if: steps.check_tag.outputs.exists == 'false'
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git tag -a "${{ steps.get_version.outputs.tag }}" -m "Release ${{ steps.get_version.outputs.tag }}"
+          git push origin "${{ steps.get_version.outputs.tag }}"
+
+      - name: Create GitHub Release
+        if: steps.check_tag.outputs.exists == 'false'
+        uses: softprops/action-gh-release@v1
+        with:
+          tag_name: ${{ steps.get_version.outputs.tag }}
+          name: Release ${{ steps.get_version.outputs.tag }}
+          body_path: CHANGELOG.md
+          draft: false
+          prerelease: false
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Calculate tarball hash
+        if: steps.check_tag.outputs.exists == 'false'
+        id: tarball_hash
+        run: |
+          VERSION="${{ steps.get_version.outputs.version }}"
+          TARBALL_URL="https://github.com/${{ github.repository }}/archive/v${VERSION}.tar.gz"
+
+          # Download and calculate hash
+          curl -L "$TARBALL_URL" -o release.tar.gz
+          HASH=$(zig fetch release.tar.gz 2>&1 | grep -o '12[0-9a-f]*' || echo "")
+
+          if [ -z "$HASH" ]; then
+            echo "⚠️ Could not calculate hash automatically"
+            echo "📦 Users can get the hash by running:"
+            echo "   zig fetch --save $TARBALL_URL"
+          else
+            echo "hash=$HASH" >> $GITHUB_OUTPUT
+            echo "📦 Tarball hash: $HASH"
+          fi
+
+      - name: Post release information
+        if: steps.check_tag.outputs.exists == 'false'
+        run: |
+          echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+          echo "🎉 Release ${{ steps.get_version.outputs.tag }} created successfully!"
+          echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+          echo ""
+          echo "📦 To use this release in your project's build.zig.zon:"
+          echo ""
+          echo ".dependencies = .{"
+          echo "    .poseidon = .{"
+          echo "        .url = \"https://github.com/${{ github.repository }}/archive/${{ steps.get_version.outputs.tag }}.tar.gz\","
+          echo "        .hash = \"${{ steps.tarball_hash.outputs.hash }}\","
+          echo "    },"
+          echo "},"
+          echo ""
+          echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+
+      - name: Skip release (tag exists)
+        if: steps.check_tag.outputs.exists == 'true'
+        run: |
+          echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+          echo "⚠️  Skipping release - tag ${{ steps.get_version.outputs.tag }} already exists"
+          echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+          echo ""
+          echo "To create a new release:"
+          echo "1. Update the VERSION file with a new version number"
+          echo "2. Commit the change"
+          echo "3. Create and merge a PR"
+          echo ""
+          echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+

.github/workflows/ci.yml

@@ -31,7 +31,7 @@ jobs:
           zig-version: 0.14.0
 
       - name: Lint
-        run: zig fmt --check src/*.zig
+        run: zig fmt --check src/
 
   test:
     runs-on: ubuntu-latest

README.md

@@ -36,12 +36,19 @@ Add `zig-poseidon` as a dependency in your `build.zig.zon`:
 ```zig
 .dependencies = .{
     .poseidon = .{
-        .url = "https://github.com/jsign/zig-poseidon/archive/<commit-hash>.tar.gz",
-        .hash = "<hash>",
+        .url = "https://github.com/blockblaz/zig-poseidon/archive/v0.2.0.tar.gz",
+        .hash = "122...", // Get hash by running: zig fetch --save <url>
     },
 },
 ```
 
+**Get the correct hash:**
+```bash
+zig fetch --save https://github.com/blockblaz/zig-poseidon/archive/v0.2.0.tar.gz
+```
+
+**Latest version:** See [Releases](https://github.com/blockblaz/zig-poseidon/releases) for the most recent version.
+
 ## Usage
 
 ### Using BabyBear16
@@ -150,6 +157,45 @@ Both implementations include tests ensuring the naive and optimized (Montgomery)
 - Add benchmarks and performance optimizations
 - Add more S-Box degrees as needed
 
+## Versioning and Releases
+
+This project follows [Semantic Versioning](https://semver.org/). 
+
+**Current version:** `0.2.0`
+
+### Release Process
+
+Releases are automatically created when Pull Requests from `main` are merged to the `release` branch:
+
+1. Develop and merge features to `main` branch
+2. When ready to release, update the `VERSION` file on `main`
+3. Create a PR from `main` to `release` branch
+4. After merge to `release`, the workflow automatically:
+   - Creates a Git tag (e.g., `v0.2.0`)
+   - Generates a changelog
+   - Creates a GitHub Release
+   - Calculates the tarball hash for dependencies
+
+**Why a release branch?**
+- ✅ Control when releases happen
+- ✅ Not every feature triggers a release
+- ✅ Batch multiple features into one release
+
+See [RELEASING.md](RELEASING.md) for detailed release instructions.
+
+### Using Specific Versions
+
+Always pin to a specific version in your `build.zig.zon`:
+
+```zig
+.poseidon = .{
+    .url = "https://github.com/blockblaz/zig-poseidon/archive/v0.2.0.tar.gz",
+    .hash = "122...", // specific hash for v0.2.0
+},
+```
+
+**Find releases:** [GitHub Releases](https://github.com/blockblaz/zig-poseidon/releases)
+
 ## License
 
 MIT

VERSION

@@ -0,0 +1,2 @@
+0.2.0
+

build.zig

@@ -4,19 +4,11 @@ pub fn build(b: *std.Build) void {
     const target = b.standardTargetOptions(.{});
     const optimize = b.standardOptimizeOption(.{});
 
-    // Generic Poseidon2 module
-    _ = b.addModule("poseidon2", .{
-        .root_source_file = b.path("src/poseidon2/poseidon2.zig"),
-    });
-
-    // BabyBear16 instance
-    _ = b.addModule("babybear16", .{
-        .root_source_file = b.path("src/instances/babybear16.zig"),
-    });
-
-    // KoalaBear16 instance (compatible with Rust hash-sig)
-    _ = b.addModule("koalabear16", .{
-        .root_source_file = b.path("src/instances/koalabear16.zig"),
+    // Main module - exports everything
+    _ = b.addModule("poseidon", .{
+        .root_source_file = b.path("src/root.zig"),
+        .target = target,
+        .optimize = optimize,
     });
 
     const lib = b.addStaticLibrary(.{

build.zig.zon

@@ -0,0 +1,18 @@
+.{
+    .name = .zig_poseidon,
+    .version = "0.2.0",
+    .fingerprint = 0x4cb45c65d8967708,
+    .minimum_zig_version = "0.14.0",
+
+    .dependencies = .{},
+
+    .paths = .{
+        "build.zig",
+        "build.zig.zon",
+        "src",
+        "README.md",
+        "LICENSE",
+        "VERSION",
+    },
+}
+

src/instances/koalabear16.zig

@@ -29,7 +29,7 @@ const DIAGONAL = [WIDTH]u32{
     parseHex("7fffff7f"), // -1/2^24
 };
 
-const Poseidon2KoalaBear = poseidon2.Poseidon2(
+pub const Poseidon2KoalaBear = poseidon2.Poseidon2(
     koalabear,
     WIDTH,
     INTERNAL_ROUNDS,

src/root.zig

@@ -0,0 +1,14 @@
+// Root module for zig-poseidon
+// Re-exports all components
+
+pub const babybear16 = @import("instances/babybear16.zig");
+pub const koalabear16 = @import("instances/koalabear16.zig");
+pub const poseidon2 = @import("poseidon2/poseidon2.zig");
+
+// Convenience type exports
+pub const Poseidon2BabyBear = babybear16.Poseidon2BabyBear;
+pub const Poseidon2KoalaBear = koalabear16.Poseidon2KoalaBear;
+
+test {
+    @import("std").testing.refAllDecls(@This());
+}