diff --git a/README.md b/README.md
index b7b68c52..e7e990fd 100644
--- a/README.md
+++ b/README.md
@@ -625,16 +625,16 @@ Deployment and monitoring (future)
 
 ## Extensions
 
-AI-DLC supports an extension system that lets you layer additional rules on top of the core workflow. Extensions are markdown files organized under `aws-aidlc-rule-details/extensions/` and grouped by category (e.g., `security/`, `testing/`).
+AI-DLC supports an extension system that lets you layer additional rules on top of the core workflow. Extensions are markdown files organized under `aws-aidlc-rule-details/extensions/` and grouped by category (e.g., `security/`, `compliance/`, `testing/`).
 
 ### How Extensions Work
 
 Each extension consists of two files placed in the same directory:
 
 - A **rules file** (e.g., `security-baseline.md`) containing the extension's rules.
-- An **opt-in file** (e.g., `security-baseline.opt-in.md`) containing a structured multiple-choice question presented to the user during Requirements Analysis.
+- An **opt-in file** (e.g., `security-baseline.opt-in.md`) containing metadata for the extension selection menu.
 
-At workflow start, AI-DLC scans the `extensions/` directory and loads only `*.opt-in.md` files. During Requirements Analysis, it presents each opt-in prompt to the user. When the user opts in, the corresponding rules file is loaded (derived by naming convention: strip `.opt-in.md`, append `.md`). When the user opts out, the rules file is never loaded. Extensions without a matching `*.opt-in.md` file are always enforced.
+At workflow start, AI-DLC scans the `extensions/` directory and loads only `*.opt-in.md` files. During Requirements Analysis, it presents a **consolidated selection menu** listing all available extensions — the user selects which ones to enable in a single answer. When the user opts in, the corresponding rules file is loaded (derived by naming convention: strip `.opt-in.md`, append `.md`). When the user opts out, the rules file is never loaded. Extensions without a matching `*.opt-in.md` file are always enforced.
 
 Once enabled, extension rules are blocking constraints — at each stage, the model verifies compliance before allowing the stage to proceed.
 
@@ -645,31 +645,35 @@ The `extensions/` directory ships with the following (new extensions may be adde
 ```text
 aws-aidlc-rule-details/
 └── extensions/
-    ├── security/                      # Extension category
+    ├── security/                      # Security rules
     │   └── baseline/
-    │       ├── security-baseline.md          # Baseline security rules
-    │       └── security-baseline.opt-in.md   # Opt-in prompt
-    └── testing/                       # Extension category
+    │       ├── security-baseline.md
+    │       └── security-baseline.opt-in.md
+    └── testing/                       # Testing rules
         └── property-based/
-            ├── property-based-testing.md          # Property-based testing rules
-            └── property-based-testing.opt-in.md   # Opt-in prompt
+            ├── property-based-testing.md
+            └── property-based-testing.opt-in.md
 ```
 
 > [!IMPORTANT]
-> The security extension rules are provided as a directional reference for building effective security rules within AI-DLC workflows. Each organization should build, customize, and thoroughly test their own security rules before deploying in production workflows.
+> The security extension rules are provided as a directional reference for building effective rules within AI-DLC workflows. Each organization should build, customize, and thoroughly test their own rules before deploying in production workflows.
 
 ### Adding Your Own Extensions
 
 You can extend an existing category or create an entirely new one.
 
-1. Create a directory under `extensions/` (e.g., `security/compliance/` or `performance/baseline/`).
-2. Add a **rules file** (e.g., `compliance.md`). Follow the same structure as `security-baseline.md`:
+1. Create a directory under `extensions/` (e.g., `compliance/pci-dss/` or `performance/baseline/`).
+2. Add a **rules file** (e.g., `pci-dss-controls.md`). Follow the same structure as `security-baseline.md`:
    - Define each rule as a heading in the format `## Rule <PREFIX-NN>: <Title>` where the prefix is a short category identifier and NN is a sequential number (e.g., `COMPLIANCE-01`, `COMPLIANCE-02`). These IDs are referenced in audit logs and compliance summaries, so they must be unique across all loaded extensions.
    - Include a **Rule** section describing the requirement.
    - Include a **Verification** section with concrete checks the model should evaluate.
-3. Add a matching **opt-in file** using the naming convention `<name>.opt-in.md` (e.g., `compliance.opt-in.md`). See `security-baseline.opt-in.md` for the expected format. Omitting this file means the extension is always enforced with no user opt-out.
+3. Add a matching **opt-in file** using the naming convention `<name>.opt-in.md` (e.g., `pci-dss.opt-in.md`). See `security-baseline.opt-in.md` for the expected format. Omitting this file means the extension is always enforced with no user opt-out.
 4. Rules are blocking by default — if verification criteria are not met, the stage cannot proceed until the finding is resolved.
 
+### Community Extensions
+
+Community extensions are authored in external repositories and registered in the `community-extensions-index.yaml` at the repository root. To install one, copy its files into the matching `extensions/` subdirectory. See the index file for available community extensions and install instructions.
+
 ---
 
 ## Tenets
diff --git a/aidlc-rules/aws-aidlc-rule-details/extensions/README.md b/aidlc-rules/aws-aidlc-rule-details/extensions/README.md
new file mode 100644
index 00000000..49b97464
--- /dev/null
+++ b/aidlc-rules/aws-aidlc-rule-details/extensions/README.md
@@ -0,0 +1,39 @@
+# Extensions
+
+This folder is read by the AI-DLC rules loader at workflow start. Place installed extension files here — the AI will automatically detect and load them.
+
+**This README file is not processed by the extensions loader.** The loader scans subdirectories only.
+
+---
+
+## Available Extensions
+
+| Extension | Category | Description |
+|---|---|---|
+| `security/baseline/` | security | OWASP-mapped security rules |
+| `testing/property-based/` | testing | Property-based testing rules |
+
+---
+
+## How the Loader Works
+
+At workflow start, the AI scans subdirectories under `extensions/`:
+
+1. A subfolder containing a `*.opt-in.md` file is an **opt-in extension** — during Requirements Analysis, a consolidated selection menu is presented listing all available extensions for the user to choose from
+2. A subfolder with rule `.md` files but no `*.opt-in.md` is **always enforced** — its rules are loaded immediately at workflow start
+3. The `project-type/` subfolder is **excluded from this scan** — project-type extensions are loaded by Workspace Detection
+
+---
+
+## Installing Community Extensions
+
+Community extensions are hosted in external repositories and listed in `community-extensions-index.yaml` at the repo root. To install one, copy its rule files into the matching category subdirectory here:
+
+```bash
+mkdir -p extensions/<category>/<extension-name>
+cp <source>/*.opt-in.md <source>/*-rules.md extensions/<category>/<extension-name>/
+```
+
+Then start a new AI-DLC session to load the extension.
+
+---
diff --git a/aidlc-rules/aws-aidlc-rule-details/inception/requirements-analysis.md b/aidlc-rules/aws-aidlc-rule-details/inception/requirements-analysis.md
index bf0ea729..8880cbd3 100644
--- a/aidlc-rules/aws-aidlc-rule-details/inception/requirements-analysis.md
+++ b/aidlc-rules/aws-aidlc-rule-details/inception/requirements-analysis.md
@@ -90,11 +90,34 @@ Analyze whatever the user has provided:
 
 **When in doubt, ask questions** - incomplete requirements lead to poor implementations.
 
-### Step 5.1: Extension Opt-In Prompts
+### Step 5.1: Extension Selection
 
-**MANDATORY**: Scan all loaded `*.opt-in.md` files (loaded at workflow start from `extensions/` subdirectories) for an `## Opt-In Prompt` section. For each extension that declares one, include that question in the clarifying questions file created in Step 6. Present each opt-in question in the same language as the user's conversation.
+**MANDATORY**: Scan all loaded `*.opt-in.md` files (loaded at workflow start from `extensions/` subdirectories). Present the user with a single consolidated extension selection menu listing ALL available extensions. Present the menu in the same language as the user's conversation.
 
-After receiving answers:
+**Selection Menu Format** (include as a question in the clarifying questions file from Step 6):
+
+```markdown
+## Question: Extensions
+
+The following extensions are available for this project. Select which ones to enable:
+
+| # | Extension | Category | Description |
+|---|---|---|---|
+| 1 | [Extension Name] | [category] | [one-line description from opt-in file] |
+| 2 | [Extension Name] | [category] | [one-line description from opt-in file] |
+| ... | ... | ... | ... |
+
+Enter the numbers of extensions to enable (comma-separated), "all" to enable all, or "none" to skip.
+
+[Answer]:
+```
+
+**Rules**:
+- List ALL extensions with `*.opt-in.md` files in a single table — do NOT present them as individual questions
+- Populate the description from each extension's `*.opt-in.md` content
+- If only one extension is available, still use this format for consistency
+
+After receiving the answer:
 1. Record each extension's enablement status in `aidlc-docs/aidlc-state.md` under `## Extension Configuration`:
 
 ```markdown
diff --git a/community-extensions-index.yaml b/community-extensions-index.yaml
new file mode 100644
index 00000000..ff0e1289
--- /dev/null
+++ b/community-extensions-index.yaml
@@ -0,0 +1,32 @@
+# Community Extensions Index
+# This file provides discovery and integrity verification for community-authored extensions.
+# Community extensions are hosted in external repositories (Proposal C model).
+# Official extensions ship in aidlc-rules/aws-aidlc-rule-details/extensions/ (Proposal B model).
+#
+# To add a community extension: submit a PR adding your entry below.
+# See CONTRIBUTING.md for the full submission process.
+
+schema_version: "1.0"
+
+extensions: []
+
+# Example entry (uncomment and fill in to register a community extension):
+#
+# extensions:
+#   - name: "my-extension"
+#     display_name: "My Extension"
+#     description: "What this extension does"
+#     category: "compliance"
+#     version: "1.0.0"
+#     maturity: "new"  # new | incubating | reviewed | adopted
+#     author: "Your Name"
+#     repo: "https://github.com/your-org/your-repo"
+#     path: "path/to/extension"
+#     ref: "main"
+#     files:
+#       - name: "my-extension.opt-in.md"
+#         sha256: ""  # Required for reviewed+ maturity
+#       - name: "my-extension-rules.md"
+#         sha256: ""
+#     tags: ["compliance", "example"]
+#     install_path: "extensions/compliance/my-extension"
diff --git a/docs/WORKING-WITH-AIDLC.md b/docs/WORKING-WITH-AIDLC.md
index 136fe9ab..252427e8 100644
--- a/docs/WORKING-WITH-AIDLC.md
+++ b/docs/WORKING-WITH-AIDLC.md
@@ -257,7 +257,7 @@ See the answering tips in [Section 1](#the-question--doc--approval-flow) for the
 - **State deliberate "no" decisions clearly.** `D — no caching required at this time` signals intent. An empty answer invites the AI to make a speculative choice.
 - **Describe phased approaches inline.** `X — simple role-based workflow now; replace with external workflow engine when available` lets AIDLC design the current solution with the right extension points.
 
-> **Advanced tip — Security Extensions**: During Requirements Analysis, AIDLC will ask whether you want to enforce security extension rules. For production-grade applications, choose Yes. For prototypes, No is fine. This decision is recorded and enforced throughout Construction, so choose deliberately.
+> **Advanced tip — Extensions**: During Requirements Analysis, AIDLC presents a consolidated extension selection menu listing all available extensions (security, compliance, testing, etc.). Select the ones relevant to your project in a single answer. This decision is recorded and enforced throughout Construction, so choose deliberately.
 
 ---