diff --git a/.github/workflows/sonar.yml b/.github/workflows/sonar.yml
deleted file mode 100644
index 1918c16..0000000
--- a/.github/workflows/sonar.yml
+++ /dev/null
@@ -1,61 +0,0 @@
-name: SonarCloud
-
-on:
-  push:
-    branches: [ master ]
-  pull_request:
-    branches: [ master ]
-  workflow_dispatch:
-
-jobs:
-  sonar:
-    name: Build, test & analyze
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v6
-        with:
-          fetch-depth: 0   # full history for accurate new-code/blame attribution
-
-      - name: Set up JDK 17
-        uses: actions/setup-java@v4
-        with:
-          distribution: 'temurin'
-          java-version: '17'   # required by the Sonar scanner engine
-
-      - name: Setup .NET
-        uses: actions/setup-dotnet@v5
-        with:
-          dotnet-version: 8.0.x
-
-      - name: Cache SonarCloud packages
-        uses: actions/cache@v4
-        with:
-          path: ~/.sonar/cache
-          key: ${{ runner.os }}-sonar
-          restore-keys: ${{ runner.os }}-sonar
-
-      - name: Install Sonar + coverage tools
-        run: |
-          dotnet tool install --global dotnet-sonarscanner
-          dotnet tool install --global dotnet-coverage
-
-      - name: Build, test & analyze
-        env:
-          SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
-          # If SONAR_TOKEN is not configured yet, skip analysis instead of failing the build.
-        run: |
-          if [ -z "$SONAR_TOKEN" ]; then
-            echo "SONAR_TOKEN secret is not set - skipping SonarCloud analysis."
-            echo "See SONAR_SETUP.md to finish the one-time setup."
-            exit 0
-          fi
-          dotnet sonarscanner begin \
-            /k:"PFalkowski_Extensions.Standard" \
-            /o:"pfalkowski" \
-            /d:sonar.host.url="https://sonarcloud.io" \
-            /d:sonar.token="${SONAR_TOKEN}" \
-            /d:sonar.cs.vscoveragexml.reportsPaths="coverage.xml"
-          dotnet build --configuration Release
-          dotnet-coverage collect "dotnet test --configuration Release --no-build" -f xml -o coverage.xml
-          dotnet sonarscanner end /d:sonar.token="${SONAR_TOKEN}"
diff --git a/CHANGELOG.md b/CHANGELOG.md
index be0ddbb..49834af 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,7 +24,7 @@ All notable changes to this project are documented here. The format is based on
 ### Added
 - Black-box test coverage for previously-untested public surface (`HsVtoArgb`, `Head`/`Tail`/
   `HeadAndTail`, `PluralizeWhenNeeded`, `AsTime(TimeSpan)`, `FindMinMaxInOn`, `Scale()`, `MaxIndex`).
-- Code coverage upload to Codecov from CI, and a SonarCloud analysis workflow (see `SONAR_SETUP.md`).
+- Code coverage upload to Codecov from CI, and tokenless SonarCloud Automatic Analysis (see `SONAR_SETUP.md`).
 
 ## [11.0.0]
 
diff --git a/SONAR_SETUP.md b/SONAR_SETUP.md
index 0f6497e..565a24c 100644
--- a/SONAR_SETUP.md
+++ b/SONAR_SETUP.md
@@ -1,32 +1,22 @@
-# SonarCloud setup (one-time)
+# SonarCloud setup (one-time, no secrets)
 
-SonarCloud (now "SonarQube Cloud") is free for public repositories. The
-[`.github/workflows/sonar.yml`](.github/workflows/sonar.yml) workflow runs the analysis on every
-push/PR to `master`. It needs a one-time account setup plus a `SONAR_TOKEN` repository secret. Until
-the secret exists the workflow is a no-op (it logs a message and exits 0), so it will not turn CI red.
+SonarCloud ("SonarQube Cloud") is free for public repositories and analyzes C# via **Automatic
+Analysis** — driven by the SonarCloud GitHub App, with **no CI workflow, no config file, and no
+`SONAR_TOKEN` secret**. (This is how the sibling `PFalkowski/LoggerLite` repo is set up.)
 
 ## Steps
 
 1. Go to <https://sonarcloud.io> and **log in with GitHub**.
-2. **Analyze a new project** → choose the GitHub organization, then import
+2. **Analyze a new project** → choose the GitHub organization → import
    `PFalkowski/Extensions.Standard`.
-3. When prompted for the analysis method, pick **"With GitHub Actions"** (CI-based analysis —
-   required for C#; automatic analysis does not support C#).
-4. SonarCloud shows your **Organization Key** and **Project Key**. Confirm they match the values in
-   `sonar.yml`:
-   - `/o:` → Organization Key (the workflow assumes `pfalkowski`)
-   - `/k:` → Project Key (the workflow assumes `PFalkowski_Extensions.Standard`)
-
-   If SonarCloud generated different values, update those two lines in `sonar.yml`.
-5. SonarCloud generates a token. In GitHub: **Settings → Secrets and variables → Actions → New
-   repository secret**, name it `SONAR_TOKEN`, paste the value.
-6. (Recommended) In the SonarCloud project under **Administration → Analysis Method**, turn **off**
-   "Automatic Analysis" so it does not conflict with the CI-based analysis.
+3. Leave the analysis method on the default **Automatic Analysis**. SonarCloud now analyzes on every
+   push/PR automatically. That's it — nothing to add to the repo.
 
 ## Notes
 
-- Coverage is collected with Microsoft's `dotnet-coverage` tool and handed to Sonar via
-  `sonar.cs.vscoveragexml.reportsPaths=coverage.xml`.
-- The scanner engine runs on Java 17, which the workflow installs.
-- A green PR badge / quality gate can be added to `README.md` once the project exists:
+- **No token, no workflow.** Automatic Analysis and a CI-based scanner are mutually exclusive, which
+  is why this repo intentionally has no `sonar.yml`.
+- **Coverage** is not imported by Automatic Analysis; test coverage is tracked separately in
+  [Codecov](https://codecov.io/gh/PFalkowski/Extensions.Standard) (uploaded from `ci.yml`).
+- Optional quality-gate badge for `README.md` once the project exists:
   `[![Quality Gate](https://sonarcloud.io/api/project_badges/measure?project=PFalkowski_Extensions.Standard&metric=alert_status)](https://sonarcloud.io/summary/new_code?id=PFalkowski_Extensions.Standard)`