diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 18a5e7c..f85fca2 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -104,8 +104,7 @@ jobs:
           }
 
           $versionJson = Get-Content -Raw -Path version.json | ConvertFrom-Json
-          $patch = if ($env:BUILD_NUMBER) { $env:BUILD_NUMBER } else { "$($versionJson.patch)" }
-          $version = "$($versionJson.major).$($versionJson.minor).$patch"
+          $version = "$($versionJson.major).$($versionJson.minor).$($versionJson.patch)"
           $exists = if ($versions -contains $version) { 'true' } else { 'false' }
           Write-Output "Release $version exists on PyPI: $exists"
           "exists=$exists" | Out-File -FilePath $env:GITHUB_OUTPUT -Append -Encoding utf8
diff --git a/RELEASE.md b/RELEASE.md
new file mode 100644
index 0000000..10f0b0b
--- /dev/null
+++ b/RELEASE.md
@@ -0,0 +1,109 @@
+# Release steps (minimal)
+
+This file documents the minimal, explicit steps to bump the version and publish a release for moldflow-api.
+
+Summary (short):
+
+- Edit the root `version.json` (only this file).
+- Commit on a branch named `release/MAJOR.MINOR.PATCH` and push.
+- Wait for CI to pass on that branch.
+- Trigger the manual "Publish package (manual)" workflow in GitHub Actions and confirm.
+
+Why this works (important notes):
+
+- The canonical version source for releases is the root `version.json` in the repository root.
+- The `run.py` script (used for building and releasing locally and by many repo commands)
+  reads the `patch` value directly from the root `version.json` and will raise a
+  RuntimeError if `patch` is missing.
+- The workflow only publishes when run on a branch whose name starts with `release/` and when
+  you confirm the manual workflow dispatch.
+- The release workflow checks PyPI for an existing version and will skip publishing if that
+  exact version already exists.
+
+Minimal step-by-step
+
+1. Decide the new major/minor/patch values.
+
+   - Always set a numeric `patch` value in the root `version.json`.
+
+2. Edit `version.json` at the repository root. Example (bumping to MAJOR.MINOR.PATCH, e.g. 1.2.0):
+
+```json
+{
+  "major": "27",
+  "minor": "0",
+  "patch": "0"
+}
+```
+
+3. Commit and push on a `release/` branch. Example (use the placeholder branch name below and replace with your version):
+
+```bash
+# create branch using the target version (branch name must start with 'release/')
+# use a placeholder like 'release/MAJOR.MINOR.PATCH' and replace with your values
+git checkout -b release/MAJOR.MINOR.PATCH  # e.g. release/1.2.0
+git add version.json
+git commit -m "Bump version to MAJOR.MINOR.PATCH"  # e.g. "Bump version to 1.2.0"
+git push -u origin release/MAJOR.MINOR.PATCH
+```
+
+4. Wait for CI to pass on that branch.
+
+   - The publish workflow has a guard that requires the `ci.yml` workflow to have completed
+     successfully for the same commit before allowing publish.
+
+5. Trigger the publish workflow manually in the GitHub Actions UI for the repository.
+
+   - Open the `Publish package (manual)` workflow, choose `Run workflow`, set `confirm` to
+     `true`, and run it on your `release/MAJOR.MINOR.PATCH` branch (replace the placeholder
+     with the actual version).
+   - Alternatively, you can use the GitHub CLI (if you have it configured). Example using a
+     placeholder branch name (replace with your actual branch):
+```bash
+# example (replace with the correct workflow file name and branch if needed)
+# gh workflow run publish.yml --ref release/MAJOR.MINOR.PATCH -f confirm=true
+# e.g. --ref release/1.2.0
+```
+
+6. What the workflow does (high level):
+
+- Ensures CI (`ci.yml`) passed for the commit.
+- Computes the release version using `version.json`.
+- If the computed version already exists on PyPI the workflow will skip the publish.
+- If not present, it builds the package, uploads to PyPI (requires the repo to have
+  `PYPI_API_TOKEN` in secrets), creates a GitHub release (tag `vMAJOR.MINOR.PATCH`) and
+  deploys documentation to GitHub Pages.
+
+Local testing and notes
+
+- You can build the package locally to smoke test the build step:
+
+```bash
+python run.py build
+```
+
+- Publishing to PyPI is intentionally restricted to the manual GitHub Actions workflow.
+  If you need to test publishing to TestPyPI locally, you can use `python -m twine upload`
+  with TestPyPI credentials, but this is separate from the CI-based publish flow.
+
+Edge cases and tips
+
+- `run.py` now requires a `patch` value in the root `version.json`. It will raise a
+  RuntimeError if that key is missing. Do not rely on `run.py` falling back to any
+  environment variable.
+- If you want CI to inject a monotonic build number into the patch segment, make the CI
+  step explicitly update `version.json` (or generate a temporary `version.json`) with the
+  desired `patch` before running the build and publish steps. That keeps `run.py` and the
+  workflow in agreement.
+- The `run.py` script will write a package-local `src/moldflow/version.json` at build time;
+  you do not need to edit that file directly (it is generated and typically ignored by Git).
+
+Cleanup (optional)
+
+- After a successful release you may merge the `release/` branch to `main` (if you use merge
+  workflow) and delete the `release/` branch.
+
+Contact
+
+If anything in CI behaves unexpectedly, check the logs for the `publish` workflow and the
+`ci` workflow; feel free to open an issue or ask a maintainer.
diff --git a/run.py b/run.py
index ffcc814..5c25149 100644
--- a/run.py
+++ b/run.py
@@ -73,7 +73,6 @@
 SITE_PACKAGES = 'moldflow-site-packages'
 VERSION_JSON = 'version.json'
 VERSION = ''
-BUILD_NUMBER = os.environ.get('BUILD_NUMBER', '0')
 
 # FILE TYPES
 PY_FILES_EXT = '.py'
@@ -588,14 +587,13 @@ def set_version():
 
     # Set global version for use in other functions
     global VERSION
-    patch_value = vers_json_dict.get('patch', BUILD_NUMBER)
-    VERSION = f"{vers_json_dict['major']}.{vers_json_dict['minor']}.{patch_value}"
+    VERSION = f"{vers_json_dict['major']}.{vers_json_dict['minor']}.{vers_json_dict['patch']}"
 
     # Create package version.json with complete version info
     package_version = {
         "major": vers_json_dict['major'],
         "minor": vers_json_dict['minor'],
-        "patch": patch_value,
+        "patch": vers_json_dict['patch'],
     }
 
     # Ensure package directory exists