diff --git a/.github/workflows/docs-deploy.yml b/.github/workflows/docs-deploy.yml
new file mode 100644
index 0000000..53719e2
--- /dev/null
+++ b/.github/workflows/docs-deploy.yml
@@ -0,0 +1,193 @@
+name: Deploy Docs
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - "docs/**"
+      - "src/**/*.cs"
+      - "src/**/*.csproj"
+      - "Directory.Build.props"
+      - "Directory.Packages.props"
+      - "*.md"
+      - ".github/workflows/docs-deploy.yml"
+  release:
+    types: [published]
+  workflow_dispatch:
+
+permissions:
+  contents: write
+
+concurrency:
+  group: docs-deploy
+  cancel-in-progress: false
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    outputs:
+      version_path: ${{ steps.version.outputs.path }}
+      is_release: ${{ steps.version.outputs.is_release }}
+      version_tag: ${{ steps.version.outputs.tag }}
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: "9.0.x"
+
+      - name: Cache NuGet packages
+        uses: actions/cache@v4
+        with:
+          path: ~/.nuget/packages
+          key: nuget-${{ runner.os }}-${{ hashFiles('**/*.csproj', '**/Directory.Packages.props') }}
+          restore-keys: nuget-${{ runner.os }}-
+
+      - name: Restore solution
+        run: dotnet restore Compendium.sln
+
+      - name: Install DocFX
+        run: dotnet tool install -g docfx
+
+      - name: Determine target version path
+        id: version
+        run: |
+          if [ "${{ github.event_name }}" = "release" ]; then
+            TAG="${{ github.event.release.tag_name }}"
+            VERSION_NUM="${TAG#v}"
+            MAJOR_MINOR=$(echo "$VERSION_NUM" | cut -d. -f1-2)
+            echo "path=v$MAJOR_MINOR" >> "$GITHUB_OUTPUT"
+            echo "is_release=true" >> "$GITHUB_OUTPUT"
+            echo "tag=$TAG" >> "$GITHUB_OUTPUT"
+          else
+            echo "path=main" >> "$GITHUB_OUTPUT"
+            echo "is_release=false" >> "$GITHUB_OUTPUT"
+            echo "tag=" >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Sync ROADMAP into docs (if present)
+        run: |
+          if [ -f ROADMAP.md ]; then
+            {
+              echo '---'
+              echo 'uid: roadmap'
+              echo 'title: Roadmap'
+              echo '---'
+              echo
+              cat ROADMAP.md
+            } > docs/roadmap.md
+            echo "ROADMAP.md inlined into docs/roadmap.md"
+          else
+            echo "ROADMAP.md not found — keeping docs/roadmap.md placeholder"
+          fi
+
+      - name: Generate API metadata
+        run: docfx metadata docs/docfx.json
+
+      - name: Build documentation site
+        run: docfx build docs/docfx.json
+
+      - name: Upload site artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: docs-site
+          path: docs/_site/
+          retention-days: 7
+
+  deploy:
+    needs: build
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - name: Download site artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: docs-site
+          path: site/
+
+      - name: Checkout or initialize gh-pages
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          set -euo pipefail
+          mkdir -p gh-pages
+          cd gh-pages
+          git init -q -b gh-pages
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+          git remote add origin "https://x-access-token:${GITHUB_TOKEN}@github.com/${GITHUB_REPOSITORY}.git"
+          if git fetch origin gh-pages --depth=1 2>/dev/null; then
+            git reset --hard origin/gh-pages
+            echo "Existing gh-pages checked out."
+          else
+            echo "No gh-pages branch yet — bootstrapping."
+          fi
+
+      - name: Deploy site to versioned path
+        env:
+          TARGET: ${{ needs.build.outputs.version_path }}
+          IS_RELEASE: ${{ needs.build.outputs.is_release }}
+          TAG: ${{ needs.build.outputs.version_tag }}
+        run: |
+          set -euo pipefail
+          cd gh-pages
+
+          # 1. Replace target subdir
+          rm -rf "$TARGET"
+          mkdir -p "$TARGET"
+          cp -r ../site/. "$TARGET/"
+
+          # 2. On release: also refresh latest/ and append to versions.json
+          if [ "$IS_RELEASE" = "true" ]; then
+            rm -rf latest
+            mkdir -p latest
+            cp -r ../site/. latest/
+
+            if [ ! -f versions.json ]; then
+              echo "[]" > versions.json
+            fi
+            jq --arg target "$TARGET" --arg tag "$TAG" \
+              'map(select(.version != $target)) | [{"version": $target, "title": $tag, "aliases": []}] + .' \
+              versions.json > versions.json.new
+            mv versions.json.new versions.json
+          fi
+
+          # 3. Ensure root redirect (latest > main)
+          if [ -d "latest" ]; then
+            REDIRECT_TARGET="latest/"
+          else
+            REDIRECT_TARGET="main/"
+          fi
+          cat > index.html <<HTML
+          <!DOCTYPE html>
+          <html lang="en">
+            <head>
+              <meta charset="utf-8" />
+              <title>Compendium documentation</title>
+              <meta http-equiv="refresh" content="0; url=./${REDIRECT_TARGET}" />
+              <link rel="canonical" href="https://sassy-solutions.github.io/compendium/${REDIRECT_TARGET}" />
+            </head>
+            <body>
+              <p>Redirecting to <a href="./${REDIRECT_TARGET}">./${REDIRECT_TARGET}</a>…</p>
+            </body>
+          </html>
+          HTML
+
+          # 4. Initial files
+          [ -f versions.json ] || echo "[]" > versions.json
+          touch .nojekyll
+
+      - name: Commit and push gh-pages
+        run: |
+          set -euo pipefail
+          cd gh-pages
+          git add -A
+          if git diff --cached --quiet; then
+            echo "No changes to publish."
+            exit 0
+          fi
+          git commit -m "docs: deploy ${{ needs.build.outputs.version_path }} from ${{ github.sha }}"
+          git push origin gh-pages
diff --git a/docs/.gitignore b/docs/.gitignore
new file mode 100644
index 0000000..270b107
--- /dev/null
+++ b/docs/.gitignore
@@ -0,0 +1,4 @@
+_site/
+api/
+obj/
+.docfx/
diff --git a/docs/adapters/aspnetcore.md b/docs/adapters/aspnetcore.md
new file mode 100644
index 0000000..f56a356
--- /dev/null
+++ b/docs/adapters/aspnetcore.md
@@ -0,0 +1,5 @@
+# Compendium.Adapters.AspNetCore
+
+> Coming soon — tracked in [POM-184](https://github.com/sassy-solutions/compendium/issues?q=is%3Aissue+POM-184).
+
+ASP.NET Core integration: tenant validation middleware, problem details, auth helpers.
diff --git a/docs/adapters/lemonsqueezy.md b/docs/adapters/lemonsqueezy.md
new file mode 100644
index 0000000..7f97782
--- /dev/null
+++ b/docs/adapters/lemonsqueezy.md
@@ -0,0 +1,5 @@
+# Compendium.Adapters.LemonSqueezy
+
+> Coming soon — tracked in [POM-184](https://github.com/sassy-solutions/compendium/issues?q=is%3Aissue+POM-184).
+
+LemonSqueezy billing adapter.
diff --git a/docs/adapters/listmonk.md b/docs/adapters/listmonk.md
new file mode 100644
index 0000000..fe3e62b
--- /dev/null
+++ b/docs/adapters/listmonk.md
@@ -0,0 +1,5 @@
+# Compendium.Adapters.Listmonk
+
+> Coming soon — tracked in [POM-184](https://github.com/sassy-solutions/compendium/issues?q=is%3Aissue+POM-184).
+
+Listmonk newsletter adapter.
diff --git a/docs/adapters/openrouter.md b/docs/adapters/openrouter.md
new file mode 100644
index 0000000..04f1411
--- /dev/null
+++ b/docs/adapters/openrouter.md
@@ -0,0 +1,5 @@
+# Compendium.Adapters.OpenRouter
+
+> Coming soon — tracked in [POM-184](https://github.com/sassy-solutions/compendium/issues?q=is%3Aissue+POM-184).
+
+OpenRouter AI provider adapter.
diff --git a/docs/adapters/postgresql.md b/docs/adapters/postgresql.md
new file mode 100644
index 0000000..bafa037
--- /dev/null
+++ b/docs/adapters/postgresql.md
@@ -0,0 +1,5 @@
+# Compendium.Adapters.PostgreSQL
+
+> Coming soon — tracked in [POM-184](https://github.com/sassy-solutions/compendium/issues?q=is%3Aissue+POM-184).
+
+PostgreSQL event store and projection store.
diff --git a/docs/adapters/redis.md b/docs/adapters/redis.md
new file mode 100644
index 0000000..29bff4e
--- /dev/null
+++ b/docs/adapters/redis.md
@@ -0,0 +1,5 @@
+# Compendium.Adapters.Redis
+
+> Coming soon — tracked in [POM-184](https://github.com/sassy-solutions/compendium/issues?q=is%3Aissue+POM-184).
+
+Redis cache adapter.
diff --git a/docs/adapters/stripe.md b/docs/adapters/stripe.md
new file mode 100644
index 0000000..1ccbe99
--- /dev/null
+++ b/docs/adapters/stripe.md
@@ -0,0 +1,5 @@
+# Compendium.Adapters.Stripe
+
+> Coming soon — tracked in [POM-184](https://github.com/sassy-solutions/compendium/issues?q=is%3Aissue+POM-184).
+
+Stripe billing adapter.
diff --git a/docs/adapters/toc.yml b/docs/adapters/toc.yml
new file mode 100644
index 0000000..73221e5
--- /dev/null
+++ b/docs/adapters/toc.yml
@@ -0,0 +1,16 @@
+- name: ASP.NET Core
+  href: aspnetcore.md
+- name: PostgreSQL
+  href: postgresql.md
+- name: Redis
+  href: redis.md
+- name: Zitadel
+  href: zitadel.md
+- name: Stripe
+  href: stripe.md
+- name: LemonSqueezy
+  href: lemonsqueezy.md
+- name: Listmonk
+  href: listmonk.md
+- name: OpenRouter
+  href: openrouter.md
diff --git a/docs/adapters/zitadel.md b/docs/adapters/zitadel.md
new file mode 100644
index 0000000..65acb9e
--- /dev/null
+++ b/docs/adapters/zitadel.md
@@ -0,0 +1,5 @@
+# Compendium.Adapters.Zitadel
+
+> Coming soon — tracked in [POM-184](https://github.com/sassy-solutions/compendium/issues?q=is%3Aissue+POM-184).
+
+Zitadel OIDC identity adapter.
diff --git a/docs/adr/toc.yml b/docs/adr/toc.yml
new file mode 100644
index 0000000..080ef3c
--- /dev/null
+++ b/docs/adr/toc.yml
@@ -0,0 +1,14 @@
+- name: Index
+  href: README.md
+- name: 0001 — Result pattern
+  href: 0001-result-pattern.md
+- name: 0002 — Hexagonal architecture
+  href: 0002-hexagonal-architecture.md
+- name: 0003 — Zero-dependency Core
+  href: 0003-zero-dep-core.md
+- name: 0004 — Multi-tenancy strategy
+  href: 0004-multi-tenancy-strategy.md
+- name: 0005 — Event sourcing
+  href: 0005-event-sourcing-vs-state.md
+- name: Template
+  href: 0000-template.md
diff --git a/docs/concepts/event-sourcing.md b/docs/concepts/event-sourcing.md
new file mode 100644
index 0000000..d00bd3f
--- /dev/null
+++ b/docs/concepts/event-sourcing.md
@@ -0,0 +1,5 @@
+# Event Sourcing
+
+> Coming soon — tracked in [POM-183](https://github.com/sassy-solutions/compendium/issues?q=is%3Aissue+POM-183).
+
+Why event sourcing, append-only stores, aggregates vs projections, and snapshots in Compendium. See also [ADR 0005](../adr/0005-event-sourcing-vs-state.md).
diff --git a/docs/concepts/hexagonal-architecture.md b/docs/concepts/hexagonal-architecture.md
new file mode 100644
index 0000000..4b29163
--- /dev/null
+++ b/docs/concepts/hexagonal-architecture.md
@@ -0,0 +1,5 @@
+# Hexagonal Architecture
+
+> Coming soon — tracked in [POM-183](https://github.com/sassy-solutions/compendium/issues?q=is%3Aissue+POM-183).
+
+Core / Application / Adapters, ports vs adapters, why Compendium keeps Core dependency-free. See also [ADR 0002](../adr/0002-hexagonal-architecture.md) and [ADR 0003](../adr/0003-zero-dep-core.md).
diff --git a/docs/concepts/multi-tenancy.md b/docs/concepts/multi-tenancy.md
new file mode 100644
index 0000000..bedf6ea
--- /dev/null
+++ b/docs/concepts/multi-tenancy.md
@@ -0,0 +1,5 @@
+# Multi-tenancy
+
+> Coming soon — tracked in [POM-183](https://github.com/sassy-solutions/compendium/issues?q=is%3Aissue+POM-183).
+
+`TenantContext`, multi-source resolution (header / subdomain / JWT), and consistency validation. See also [ADR 0004](../adr/0004-multi-tenancy-strategy.md).
diff --git a/docs/concepts/result-pattern.md b/docs/concepts/result-pattern.md
new file mode 100644
index 0000000..b60a868
--- /dev/null
+++ b/docs/concepts/result-pattern.md
@@ -0,0 +1,5 @@
+# Result Pattern
+
+> Coming soon — tracked in [POM-183](https://github.com/sassy-solutions/compendium/issues?q=is%3Aissue+POM-183).
+
+`Result<T>`, `Error`, and why Compendium does not use exceptions for control flow. See also [ADR 0001](../adr/0001-result-pattern.md).
diff --git a/docs/concepts/toc.yml b/docs/concepts/toc.yml
new file mode 100644
index 0000000..8aaf73d
--- /dev/null
+++ b/docs/concepts/toc.yml
@@ -0,0 +1,8 @@
+- name: Event Sourcing
+  href: event-sourcing.md
+- name: Hexagonal Architecture
+  href: hexagonal-architecture.md
+- name: Result Pattern
+  href: result-pattern.md
+- name: Multi-tenancy
+  href: multi-tenancy.md
diff --git a/docs/docfx.json b/docs/docfx.json
new file mode 100644
index 0000000..e3b74b2
--- /dev/null
+++ b/docs/docfx.json
@@ -0,0 +1,59 @@
+{
+  "$schema": "https://raw.githubusercontent.com/dotnet/docfx/main/schemas/docfx.schema.json",
+  "metadata": [
+    {
+      "src": [
+        {
+          "files": ["**/*.csproj"],
+          "src": "../src",
+          "exclude": ["**/Compendium.Adapters.Shared.csproj"]
+        }
+      ],
+      "dest": "api",
+      "includePrivateMembers": false,
+      "disableGitFeatures": false,
+      "disableDefaultFilter": false,
+      "noRestore": false,
+      "namespaceLayout": "flattened",
+      "memberLayout": "samePage",
+      "EnumSortOrder": "alphabetic",
+      "allowCompilationErrors": false
+    }
+  ],
+  "build": {
+    "content": [
+      {
+        "files": ["**/*.{md,yml}"],
+        "exclude": ["_site/**", "obj/**"]
+      }
+    ],
+    "resource": [
+      {
+        "files": ["images/**"]
+      }
+    ],
+    "output": "_site",
+    "globalMetadata": {
+      "_appName": "Compendium",
+      "_appTitle": "Compendium — .NET event-sourcing framework",
+      "_enableSearch": true,
+      "_appFooter": "Copyright © 2026 Sassy Solutions. Released under the MIT License. <a href=\"https://github.com/sassy-solutions/compendium\">View on GitHub</a>.",
+      "_appLogoPath": "images/logo.svg",
+      "_appFaviconPath": "images/favicon.ico",
+      "_gitContribute": {
+        "repo": "https://github.com/sassy-solutions/compendium",
+        "branch": "main"
+      },
+      "_disableContribution": false
+    },
+    "template": ["default", "modern"],
+    "postProcessors": ["ExtractSearchIndex"],
+    "keepFileLink": false,
+    "disableGitFeatures": false,
+    "sitemap": {
+      "baseUrl": "https://sassy-solutions.github.io/compendium/",
+      "priority": 0.5,
+      "changefreq": "weekly"
+    }
+  }
+}
diff --git a/docs/getting-started.md b/docs/getting-started.md
new file mode 100644
index 0000000..a8d3b83
--- /dev/null
+++ b/docs/getting-started.md
@@ -0,0 +1,13 @@
+# Getting Started
+
+> Coming soon — tracked in [POM-182](https://github.com/sassy-solutions/compendium/issues?q=is%3Aissue+POM-182).
+
+This page will walk you through:
+
+1. Installing the Compendium NuGet packages
+2. Defining your first event-sourced aggregate
+3. Wiring CQRS dispatchers in `Program.cs`
+4. Dispatching a command and reading a projection
+5. Running one of the [samples](https://github.com/sassy-solutions/compendium/tree/main/samples)
+
+In the meantime, the [README](https://github.com/sassy-solutions/compendium/blob/main/README.md) has a Quick Start snippet.
diff --git a/docs/images/.gitkeep b/docs/images/.gitkeep
new file mode 100644
index 0000000..e69de29
diff --git a/docs/index.md b/docs/index.md
new file mode 100644
index 0000000..3c191b5
--- /dev/null
+++ b/docs/index.md
@@ -0,0 +1,35 @@
+---
+_layout: landing
+title: Compendium
+description: A pragmatic .NET framework for building event-sourced, multi-tenant SaaS applications.
+---
+
+# Compendium
+
+> A pragmatic .NET framework for building event-sourced, multi-tenant SaaS applications.
+
+Compendium distills years of building event-sourced SaaS into a small set of focused .NET 9 packages: DDD primitives, CQRS handlers, an event store, multi-tenancy, and ready-to-use adapters for PostgreSQL, Redis, Zitadel, Stripe, LemonSqueezy, Listmonk, OpenRouter, and ASP.NET Core.
+
+## Why Compendium?
+
+- **Zero-dependency Core** — Pure DDD primitives (`AggregateRoot<TId>`, `ValueObject`, `Result<T>`, `Error`) with no dependencies beyond the .NET BCL. See [ADR 0003](adr/0003-zero-dep-core.md).
+- **CQRS + Event Sourcing built-in** — Command/query dispatchers, event store interfaces, and a PostgreSQL adapter wired out of the box. See [ADR 0005](adr/0005-event-sourcing-vs-state.md).
+- **Multi-tenancy native** — Tenant context, resolution, and scoping baked into the primitives. See [ADR 0004](adr/0004-multi-tenancy-strategy.md).
+- **Result pattern everywhere** — No control-flow exceptions. Every fallible operation returns `Result<T>`. See [ADR 0001](adr/0001-result-pattern.md).
+- **Hexagonal architecture, strict** — Ports and adapters, with a clear separation between Core, Application, and Adapters. See [ADR 0002](adr/0002-hexagonal-architecture.md).
+- **Modular adapters** — Pick only what you need.
+
+## Where to start
+
+- New to Compendium? → [Getting Started](getting-started.md)
+- Want to understand the design? → [Concepts](concepts/event-sourcing.md) and [Architecture Decisions](adr/README.md)
+- Looking for a specific adapter? → [Adapters](adapters/aspnetcore.md)
+- Wondering what's next? → [Roadmap](roadmap.md)
+
+## Status
+
+Compendium is at **`v1.0.0-preview.1`**. APIs in `Compendium.Core` and `Compendium.Abstractions.*` are intended to be stable; adapter APIs may evolve based on production feedback. See [CHANGELOG](https://github.com/sassy-solutions/compendium/blob/main/CHANGELOG.md) for what has shipped.
+
+## License
+
+MIT © 2026 Sassy Solutions. See [LICENSE](https://github.com/sassy-solutions/compendium/blob/main/LICENSE).
diff --git a/docs/roadmap.md b/docs/roadmap.md
new file mode 100644
index 0000000..3c6d542
--- /dev/null
+++ b/docs/roadmap.md
@@ -0,0 +1,12 @@
+---
+uid: roadmap
+title: Roadmap
+---
+
+# Roadmap
+
+The canonical, living roadmap is at [`ROADMAP.md`](https://github.com/sassy-solutions/compendium/blob/main/ROADMAP.md) in the repository root, alongside the source. It captures vision, themes, what's next, and what is intentionally out of scope.
+
+A copy is rendered below at build time when available; otherwise visit GitHub for the latest.
+
+> If you'd like to influence the roadmap, please vote (👍) on issues tagged [`roadmap-input`](https://github.com/sassy-solutions/compendium/issues?q=is%3Aissue+label%3Aroadmap-input) or open a [Discussion](https://github.com/sassy-solutions/compendium/discussions).
diff --git a/docs/toc.yml b/docs/toc.yml
new file mode 100644
index 0000000..53ee015
--- /dev/null
+++ b/docs/toc.yml
@@ -0,0 +1,14 @@
+- name: Home
+  href: index.md
+- name: Getting Started
+  href: getting-started.md
+- name: Concepts
+  href: concepts/
+- name: Adapters
+  href: adapters/
+- name: Architecture Decisions
+  href: adr/
+- name: Roadmap
+  href: roadmap.md
+- name: API Reference
+  href: api/