chore: Single-source version + one-command release script

AGENTS.md

@@ -8,6 +8,15 @@
 - `./scripts/format.sh` / `clang-format -i` — format (`.clang-format`, 110 cols, Google base)
 - Auth/tokens-only build (no LiveKit): `cmake -B build -S . -DDECART_BUILD_REALTIME=OFF`
   (compiles out `Client::realtime()` via the `DECART_NO_REALTIME` interface define)
+- Release: `scripts/release.sh X.Y.Z` (from `main`) bumps the version, tags, and
+  pushes; the Release workflow publishes the GitHub release on the tag.
+
+## Versioning
+
+The version lives in exactly one place — `project(decart VERSION ...)` in the
+top-level CMakeLists.txt. `<decart/version.h>` is generated from `version.h.in`
+via `configure_file`, so it can't drift from the release tag. Never hand-edit a
+version number anywhere else.
 
 ## Architecture
 

CMakeLists.txt

@@ -115,9 +115,17 @@ endif()
 add_library(decart ${DECART_SOURCES})
 add_library(decart::decart ALIAS decart)
 
+# Single source of truth for the version: the project() VERSION above. Generate
+# <decart/version.h> from it so headers can never drift from the release tag.
+configure_file(
+  "${CMAKE_CURRENT_SOURCE_DIR}/include/decart/version.h.in"
+  "${CMAKE_CURRENT_BINARY_DIR}/generated/decart/version.h"
+  @ONLY)
+
 target_include_directories(decart
   PUBLIC
     $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}/generated>
     $<INSTALL_INTERFACE:include>
   PRIVATE
     ${CMAKE_CURRENT_SOURCE_DIR}/src)
@@ -207,7 +215,11 @@ install(TARGETS decart
   ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
   RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
 
-install(DIRECTORY include/ DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+# Public headers, excluding the .in template (the generated header is installed below).
+install(DIRECTORY include/ DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+  PATTERN "*.in" EXCLUDE)
+install(FILES "${CMAKE_CURRENT_BINARY_DIR}/generated/decart/version.h"
+  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/decart)
 
 install(EXPORT decartTargets
   FILE decartTargets.cmake

include/decart/version.h → include/decart/version.h.in

@@ -1,16 +1,19 @@
 // Copyright 2026 Decart. SPDX-License-Identifier: MIT
+//
+// Generated from version.h.in by CMake — do not edit. The version is the single
+// source of truth in the top-level CMakeLists.txt `project(... VERSION ...)`.
 #pragma once
 
 #include <string>
 
 /// Major version of the Decart C++ SDK.
-#define DECART_SDK_VERSION_MAJOR 0
+#define DECART_SDK_VERSION_MAJOR @PROJECT_VERSION_MAJOR@
 /// Minor version of the Decart C++ SDK.
-#define DECART_SDK_VERSION_MINOR 1
+#define DECART_SDK_VERSION_MINOR @PROJECT_VERSION_MINOR@
 /// Patch version of the Decart C++ SDK.
-#define DECART_SDK_VERSION_PATCH 0
+#define DECART_SDK_VERSION_PATCH @PROJECT_VERSION_PATCH@
 /// Full version string of the Decart C++ SDK.
-#define DECART_SDK_VERSION "0.1.0"
+#define DECART_SDK_VERSION "@PROJECT_VERSION@"
 
 namespace decart {
 

scripts/release.sh

@@ -0,0 +1,66 @@
+#!/usr/bin/env bash
+#
+# Cut a release: bump the version (single source of truth in CMakeLists.txt),
+# commit, tag, and push. The Release workflow then verifies the tag matches the
+# project version and publishes the GitHub release.
+#
+#   scripts/release.sh 0.2.0
+#
+set -euo pipefail
+cd "$(dirname "$0")/.."
+
+if [[ $# -ne 1 ]]; then
+  echo "Usage: $0 <version>   (e.g. $0 0.2.0)" >&2
+  exit 1
+fi
+new="$1"
+
+if [[ ! "$new" =~ ^[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
+  echo "error: version must be semver X.Y.Z (got '$new')" >&2
+  exit 1
+fi
+
+branch="$(git rev-parse --abbrev-ref HEAD)"
+if [[ "$branch" != "main" ]]; then
+  echo "error: releases are cut from 'main' (on '$branch')" >&2
+  exit 1
+fi
+if [[ -n "$(git status --porcelain)" ]]; then
+  echo "error: working tree is not clean; commit or stash first" >&2
+  exit 1
+fi
+
+git pull --ff-only origin main
+
+current="$(sed -n -E 's/^[[:space:]]*VERSION[[:space:]]+([0-9]+\.[0-9]+\.[0-9]+).*/\1/p' CMakeLists.txt | head -1)"
+if [[ -z "$current" ]]; then
+  echo "error: could not find the project VERSION line in CMakeLists.txt" >&2
+  exit 1
+fi
+if [[ "$new" == "$current" ]]; then
+  echo "error: version is already $current" >&2
+  exit 1
+fi
+
+if git rev-parse -q --verify "refs/tags/v$new" >/dev/null; then
+  echo "error: tag v$new already exists" >&2
+  exit 1
+fi
+
+echo "Releasing v$new (was v$current)"
+
+# Bump the version. CMakeLists.txt is the single source of truth (version.h is
+# generated from it at build time); keep vcpkg.json's manifest version in lockstep
+# so it can't drift from the release tag.
+sed -i.bak -E "s/^([[:space:]]*VERSION[[:space:]]+)[0-9]+\.[0-9]+\.[0-9]+/\1$new/" CMakeLists.txt
+sed -i.bak -E "s/(\"version\"[[:space:]]*:[[:space:]]*\")[0-9]+\.[0-9]+\.[0-9]+(\")/\1$new\2/" vcpkg.json
+rm -f CMakeLists.txt.bak vcpkg.json.bak
+
+git add CMakeLists.txt vcpkg.json
+git commit -m "chore: release v$new"
+git tag -a "v$new" -m "decart-cpp v$new"
+
+git push origin main
+git push origin "v$new"
+
+echo "Pushed v$new — the Release workflow will publish the GitHub release."