diff --git a/docs/milestones/index.md b/docs/milestones/index.md
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+# Milestones
+
+This section documents the major milestones in the CleverAgents project timeline.
+
+## Current Milestones
+
+### [v3.8.0 — M9: Server Implementation](v3.8.0.md)
+
+v3.8.0 delivers the **CleverAgents Server** — a production-ready, multi-user deployment mode
+that enables teams to share entity definitions, execute plans on shared infrastructure, and
+collaborate across devices.
+
+**Status**: In Progress (Day 104 — 2026-04-14: 26.6% complete, 135/508 story points)
+
+Key features:
+- A2A Protocol (JSON-RPC 2.0) as the sole client-facing interface
+- FastAPI server with multi-user support
+- PostgreSQL backend for persistence
+- LangGraph Platform integration for remote actor execution
+- Docker and Kubernetes deployment
+
+[Read the full v3.8.0 documentation →](v3.8.0.md)
+
+### [v3.9.0 — Documentation and Feature Updates](v3.9.0.md)
+
+v3.9.0 is a documentation and feature update release that follows the v3.8.0 Server
+Implementation milestone. It consolidates documentation across all prior milestones,
+adds missing API reference pages, and delivers targeted feature improvements.
+
+**Status**: In Progress (Day 104 — 2026-04-14: 7.0% complete, 4/57 story points)
+
+Key updates:
+- Comprehensive milestone documentation
+- Updated API reference pages
+- Server health and diagnostics commands
+- Entity sync conflict resolution
+- Namespace ACL management
+
+[Read the full v3.9.0 documentation →](v3.9.0.md)
+
+---
+
+## Related Documentation
+
+- [Implementation Timeline](../timeline.md) — Full project timeline and milestone status
+- [Architecture](../architecture.md) — System architecture overview
+- [Architecture Decision Records (ADRs)](../adr/index.md) — Design decisions and rationale
diff --git a/docs/milestones/v3.8.0.md b/docs/milestones/v3.8.0.md
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+# v3.8.0 — M9: Server Implementation
+
+**Release**: v3.8.0
+**Milestone**: M9 — Server Implementation
+**Status**: In Progress (Day 104 — 2026-04-14: 26.6% complete, 135/508 story points)
+**Target**: v3.8.0
+
+---
+
+## Overview
+
+v3.8.0 delivers the **CleverAgents Server** — a production-ready, multi-user deployment mode
+that enables teams to share entity definitions, execute plans on shared infrastructure, and
+collaborate across devices. This milestone implements the full server stack defined in
+[ADR-047](../adr/ADR-047-acp-standard-adoption.md) and
+[ADR-048](../adr/ADR-048-server-application-architecture.md).
+
+The server exposes a single **A2A JSON-RPC 2.0** endpoint as its sole client-facing interface.
+All communication — agent interactions and platform operations alike — flows through this
+endpoint. There is no REST API, no GraphQL, no separate admin surface.
+
+---
+
+## Key Features
+
+### A2A Protocol (JSON-RPC 2.0)
+
+CleverAgents adopts the **Agent-to-Agent (A2A) Protocol** ([a2a-protocol.org](https://a2a-protocol.org))
+as the sole communication standard for all client-server interaction. The A2A standard is
+governed by the Linux Foundation (Apache 2.0) and provides:
+
+- **JSON-RPC 2.0 wire format** for all messages
+- **Agent Cards** (`/.well-known/agent.json`) for dynamic capability discovery
+- **Standard operations**: `message/send`, `message/stream`, `tasks/get`, `tasks/list`,
+  `tasks/cancel`, `tasks/subscribe`, `pushNotificationConfig/*`, `getExtendedAgentCard`
+- **SSE streaming** for real-time task status and artifact updates
+- **Task lifecycle states**: `submitted` to `working` to `input-required` to `completed` /
+  `failed` / `canceled` / `rejected`
+- **CleverAgents extension methods** (`_cleveragents/` prefix) for platform-specific
+  operations (plan lifecycle, registry CRUD, entity sync, namespace management)
+
+See [ADR-047](../adr/ADR-047-acp-standard-adoption.md) for the full protocol specification.
+
+### Transport Modes
+
+The system supports three transport configurations:
+
+**Local Mode (stdio)**
+
+The client spawns the agent as a subprocess. A2A JSON-RPC messages flow over
+stdin/stdout. Platform operations are resolved in-process by `A2aLocalFacade`.
+No network, no authentication required.
+
+```
+Client Process  --stdio-->  Agent Subprocess (A2A server)
+                              |
+                              +-- A2aLocalFacade (platform ops in-process)
+                              +-- Actor Graph (LangGraph, local execution)
+```
+
+**Server Mode (HTTP)**
+
+The CLI operates as a thin client. All communication flows through the A2A
+HTTP endpoint. Actor graphs execute on LangGraph Platform via RemoteGraph.
+
+```
+Client  --HTTP-->  CleverAgents A2A Server
+                     |
+                     +-- Standard A2A --> SessionWorkflow + LangGraph Platform
+                     +-- Extension methods --> PlanService, RegistryServices, SyncService
+```
+
+**External A2A Agent**
+
+When an agent is hosted on an external A2A-compatible server, the client sends
+standard A2A operations to that server and `_cleveragents/` extension methods
+to the CleverAgents server.
+
+```
+Client  --HTTP-->  External A2A Server (agent interactions)
+        --HTTP-->  CleverAgents A2A Server (extension methods only)
+```
+
+### FastAPI Server
+
+The server Presentation layer is implemented using **FastAPI** with the A2A Python SDK's
+server-side connection handler. Key characteristics:
+
+- Single A2A JSON-RPC 2.0 endpoint — no REST routes
+- Agent Card served at `/.well-known/agent.json`
+- SSE streaming for task status and artifact updates
+- Multi-turn interaction support via `input-required` task state
+
+### Authentication
+
+Authentication uses standard HTTP security schemes declared in the Agent Card:
+
+1. Client discovers the Agent Card at `/.well-known/agent.json`
+2. Agent Card's `securitySchemes` declares supported auth mechanisms (OAuth2, API key, HTTP bearer)
+3. Client authenticates using the declared mechanism (e.g., `Authorization: Bearer <token>`)
+4. All subsequent requests include the authentication credentials
+5. The `A2A-Version` header communicates the protocol version
+
+Local mode (stdio transport) bypasses authentication — the agent subprocess runs with the
+user's local permissions.
+
+### Multi-Device Support
+
+Server mode enables multi-device collaboration:
+
+- **Shared namespaces**: `<username>/` and `<orgname>/` namespaces resolve against the server
+- **Entity sync**: `_cleveragents/sync/*` extension methods synchronize entity definitions
+  between client and server
+- **Auto-sync**: Controlled by `server.sync.auto` (default: `true`), syncing on startup and
+  at `server.sync.interval` (default: 300 seconds)
+- **Namespace isolation**: Users can only access entities in namespaces they have been granted
+  access to; the `local/` namespace is never accessible via server
+
+### PostgreSQL Backend
+
+Server mode uses **PostgreSQL** for multi-user persistence:
+
+| Component | Technology |
+|-----------|-----------|
+| Database | PostgreSQL >= 15 via SQLAlchemy |
+| Migrations | Alembic |
+| Session store | PostgreSQL (multi-user, namespace-isolated) |
+| Plan store | PostgreSQL (plan lifecycle, decision trees, artifacts) |
+
+The SQLAlchemy repository implementations are shared between client (SQLite) and server
+(PostgreSQL) where the schema is identical. Server-specific tables (authentication, namespace
+ACLs, user management) are additive.
+
+### LangGraph Platform Integration
+
+Actor graphs (StateGraphs defined in YAML) are deployed to **LangGraph Platform** as separate
+deployments. The server invokes them via **RemoteGraph**:
+
+- Different actors for different plan phases (strategy, execution, estimation) each deploy as
+  separate RemoteGraphs
+- `SessionWorkflow` orchestrates them identically to local actor graphs, but through the
+  RemoteGraph interface
+- LangGraph Platform provides production-grade graph execution with built-in scaling,
+  persistence, and monitoring
+
+### Docker and Kubernetes Deployment
+
+The server is packaged as a Docker container and deployed to Kubernetes via Helm:
+
+| Component | Technology |
+|-----------|-----------|
+| Container | Docker |
+| Orchestration | Kubernetes |
+| Configuration | Helm chart (`k8s/`) |
+| Ingress | Kubernetes Ingress (TLS termination) |
+| Database | PostgreSQL (external, managed or self-hosted) |
+| LangGraph Platform | External service (managed or self-hosted) |
+
+---
+
+## Architecture
+
+The server follows the same four-layer architecture as the client (ADR-001), sharing the
+Domain and Application layers and providing its own Infrastructure and Presentation layers:
+
+| Layer | Client | Server | Shared? |
+|-------|--------|--------|---------|
+| **Domain** | Business rules, domain models, domain events | Same | Yes |
+| **Application** | Service facades, workflows, event bus | Same | Yes |
+| **Infrastructure** | SQLite, local sandbox, `A2aLocalFacade` | PostgreSQL, LangGraph RemoteGraph, A2A SDK server | No |
+| **Presentation** | CLI (Typer), TUI (Textual), IDE plugin | A2A JSON-RPC 2.0 endpoint (FastAPI) | No |
+
+The shared Domain and Application layers are consumed as a Python package dependency,
+ensuring zero behavioral drift between local and server modes.
+
+### Wire Format Examples
+
+**Sending a message (JSON-RPC 2.0 request):**
+
+```json
+{
+  "jsonrpc": "2.0",
+  "id": 1,
+  "method": "message/send",
+  "params": {
+    "message": {
+      "role": "user",
+      "parts": [{ "text": "Refactor the auth module to use dependency injection" }]
+    }
+  }
+}
+```
+
+**Task created (response):**
+
+```json
+{
+  "jsonrpc": "2.0",
+  "id": 1,
+  "result": {
+    "id": "task_01HXRCF1...",
+    "status": { "state": "working" }
+  }
+}
+```
+
+**Extension method (platform operation):**
+
+```json
+{
+  "jsonrpc": "2.0",
+  "id": 42,
+  "method": "_cleveragents/plan/status",
+  "params": { "plan_id": "01HXRCF1..." }
+}
+```
+
+**Error response:**
+
+```json
+{
+  "jsonrpc": "2.0",
+  "id": 1,
+  "error": {
+    "code": -32001,
+    "message": "Plan not found",
+    "data": { "plan_id": "01HXRCF1..." }
+  }
+}
+```
+
+---
+
+## CLI Commands
+
+### Server Configuration
+
+```bash
+# Configure server connection
+ca config set server.url https://your-server.example.com
+ca config set server.token <your-token>
+
+# Enable/disable auto-sync
+ca config set server.sync.auto true
+ca config set server.sync.interval 300
+```
+
+### Entity Sync
+
+```bash
+# Pull server namespace entities to local cache
+ca sync pull
+
+# Push local entity definitions to a server namespace
+ca sync push
+
+# Compare local and server entity versions
+ca sync status
+```
+
+### Namespace Management
+
+```bash
+# List available namespaces (local + server)
+ca namespace list
+
+# Use a server namespace as default
+ca config set core.namespace freemo/
+```
+
+---
+
+## Quick Start
+
+### Local Mode (No Server Required)
+
+Local mode works fully offline with zero configuration:
+
+```bash
+# Install CleverAgents
+pip install cleveragents
+
+# Start a session (local mode, A2A over stdio)
+ca session start
+
+# Execute a plan locally
+ca plan run "Refactor the auth module"
+```
+
+### Server Mode
+
+**Step 1 — Deploy the server** using the Helm chart:
+
+```bash
+helm install cleveragents k8s/ \
+  --set database.url=postgresql://user:pass@host/db \
+  --set langgraph.url=https://your-langgraph-platform.example.com
+```
+
+**Step 2 — Configure the CLI** to connect to the server:
+
+```bash
+ca config set server.url https://your-server.example.com
+ca config set server.token <your-token>
+```
+
+**Step 3 — Verify the connection** by fetching the Agent Card:
+
+```bash
+ca server status
+```
+
+**Step 4 — Sync entities** from the server:
+
+```bash
+ca sync pull
+```
+
+**Step 5 — Execute a plan on the server**:
+
+```bash
+ca plan run "Refactor the auth module" --server
+```
+
+---
+
+## Error Code Reference
+
+A2A uses JSON-RPC 2.0 integer error codes:
+
+| Code | Meaning | Domain Exception |
+|------|---------|-----------------|
+| `-32700` | Parse error (malformed JSON) | — |
+| `-32600` | Invalid request | — |
+| `-32601` | Method not found | `A2aOperationNotFoundError` |
+| `-32602` | Invalid params | `ValidationError` |
+| `-32603` | Internal error | Any unhandled `Exception` |
+| `-32001` | Entity not found | `ResourceNotFoundError` |
+| `-32002` | Authentication required | `AuthenticationError` |
+| `-32003` | Authorization forbidden | `AuthorizationError` |
+| `-32004` | Invalid state | `BusinessRuleViolation` |
+| `-32005` | Already exists | `DuplicateEntityError` |
+| `-32006` | Budget exceeded | `BudgetExceededError` |
+| `-32007` | Version mismatch | `A2aVersionMismatchError` |
+| `-32008` | Plan error | `PlanError` |
+
+---
+
+## Related ADRs
+
+| ADR | Title | Relevance |
+|-----|-------|-----------|
+| [ADR-023](../adr/ADR-023-server-mode.md) | Server Mode | Defines local vs. server deployment modes |
+| [ADR-026](../adr/ADR-026-agent-client-protocol.md) | Agent-to-Agent Protocol (A2A) | Original A2A boundary role definition |
+| [ADR-047](../adr/ADR-047-acp-standard-adoption.md) | A2A Standard Adoption | Adopts external A2A standard, JSON-RPC 2.0 wire format |
+| [ADR-048](../adr/ADR-048-server-application-architecture.md) | Server Application Architecture | Concrete server architecture (FastAPI, LangGraph Platform, PostgreSQL) |
+| [ADR-022](../adr/ADR-022-langchain-langgraph-integration.md) | LangChain/LangGraph Integration | LangGraph Platform as remote actor execution backend |
+| [ADR-019](../adr/ADR-019-storage-and-persistence.md) | Storage and Persistence | PostgreSQL for server-mode persistence |
+
+---
+
+## Technology Stack
+
+| Component | Version | Purpose |
+|-----------|---------|---------|
+| Python | >= 3.13 | Runtime |
+| A2A Python SDK (`a2a-sdk`) | Latest | A2A JSON-RPC 2.0 server implementation |
+| FastAPI | Latest | HTTP server framework |
+| LangGraph Platform | Latest | Remote actor graph execution |
+| PostgreSQL | >= 15 | Multi-user persistence |
+| SQLAlchemy | >= 2.0 | ORM (shared with client) |
+| Alembic | >= 1.13 | Database migrations |
+| structlog | >= 24.1 | Structured logging |
+| Redis | >= 7.0 (optional) | Caching, session affinity for multi-instance |
+| Docker | Latest | Container packaging |
+| Helm | >= 3.0 | Kubernetes deployment |
+
+---
+
+*See also: [v3.9.0](v3.9.0.md) — Documentation and feature updates following this milestone.*
+
+---
+**Automated by CleverAgents Bot**
+Supervisor: Documentation Pool | Agent: documentation-pool-supervisor
+Worker: [AUTO-DOCS-2]
diff --git a/docs/milestones/v3.9.0.md b/docs/milestones/v3.9.0.md
new file mode 100644
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+++ b/docs/milestones/v3.9.0.md
@@ -0,0 +1,136 @@
+# v3.9.0 — Documentation and Feature Updates
+
+**Release**: v3.9.0
+**Status**: In Progress (Day 104 — 2026-04-14: 7.0% complete, 4/57 story points)
+**Target**: v3.9.0
+
+---
+
+## Overview
+
+v3.9.0 is a documentation and feature update release that follows the v3.8.0 Server
+Implementation milestone. It consolidates documentation across all prior milestones,
+adds missing API reference pages, and delivers targeted feature improvements identified
+during the v3.8.0 implementation cycle.
+
+As of Day 104 (2026-04-14), v3.9.0 has 57 open issues (scope expanded from 17 to 57)
+with 4 closed. The milestone is actively receiving new issues as the v3.8.0 implementation
+surfaces documentation gaps and feature requests.
+
+---
+
+## Scope
+
+### Documentation Updates
+
+v3.9.0 addresses documentation gaps across the entire CleverAgents documentation surface:
+
+- **Milestone documentation**: Comprehensive guides for v3.8.0 (M9: Server Implementation)
+  and all prior milestones
+- **API reference**: Updated API reference pages for new modules introduced in v3.8.0
+  (A2A protocol, server application, authentication)
+- **Architecture documentation**: Updated architecture overview reflecting the server
+  deployment mode and A2A protocol adoption
+- **ADR cross-references**: Ensuring all ADRs (ADR-047, ADR-048) are properly linked
+  from relevant documentation pages
+- **Quick start guides**: Updated quick start guides for both local and server modes
+- **FAQ updates**: New FAQ entries for common server deployment questions
+
+### Feature Updates
+
+Feature improvements targeted for v3.9.0 include:
+
+- **Server health commands**: `ca server status` and `ca server ping` for connection
+  diagnostics
+- **Sync conflict resolution UI**: Interactive conflict resolution for entity sync
+  operations (`ca sync pull --interactive`)
+- **Agent Card inspection**: `ca server card` command to display the server's Agent Card
+  in human-readable format
+- **Token management**: `ca server token` commands for managing authentication tokens
+- **Namespace ACL management**: `ca namespace acl` commands for managing namespace
+  access control lists
+
+---
+
+## Documentation Standards
+
+All documentation in v3.9.0 follows the project's documentation standards:
+
+- **Continuous documentation** — updated alongside code, not after the fact
+- **Single documentation surface** — one canonical location per doc type
+- **Traceability** — logical references to ADRs and specifications, not line numbers
+- **MkDocs-compatible** — all files are valid MkDocs Markdown with proper navigation
+
+### Documentation Structure
+
+```
+docs/
+  milestones/          # Per-milestone documentation (NEW in v3.9.0)
+    v3.8.0.md          # M9: Server Implementation
+    v3.9.0.md          # Documentation and feature updates (this file)
+  adr/                 # Architecture Decision Records (ADR-001 through ADR-048)
+  api/                 # API reference (auto-generated + hand-written)
+  development/         # Developer guides
+  modules/             # Module-level usage guides
+  reference/           # Comprehensive reference documentation
+```
+
+---
+
+## Key Changes from v3.8.0
+
+| Area | Change |
+|------|--------|
+| Documentation | Milestone docs for v3.8.0 and v3.9.0 added to `docs/milestones/` |
+| Navigation | `mkdocs.yml` updated with Milestones section |
+| API Reference | New pages for A2A protocol, server application, authentication modules |
+| CLI | `ca server status`, `ca server ping`, `ca server card` commands |
+| CLI | `ca server token` token management commands |
+| CLI | `ca namespace acl` namespace ACL management commands |
+| Sync | Interactive conflict resolution for `ca sync pull` |
+
+---
+
+## Migration Notes
+
+v3.9.0 is backward-compatible with v3.8.0. No breaking changes are introduced.
+
+If you are upgrading from a pre-v3.8.0 release:
+
+1. Review the [v3.8.0 migration guide](v3.8.0.md#quick-start) for server setup instructions
+2. Update your CLI to v3.9.0: `pip install --upgrade cleveragents`
+3. Run `ca sync pull` to fetch the latest entity definitions from your server
+
+---
+
+## Related Documentation
+
+- [v3.8.0 — M9: Server Implementation](v3.8.0.md) — The milestone this release documents
+- [Architecture](../architecture.md) — System architecture overview
+- [ADR-047 — A2A Standard Adoption](../adr/ADR-047-acp-standard-adoption.md)
+- [ADR-048 — Server Application Architecture](../adr/ADR-048-server-application-architecture.md)
+- [Implementation Timeline](../timeline.md) — Full project timeline and milestone status
+- [FAQ](../faq.md) — Frequently asked questions
+
+---
+
+## Progress Tracking
+
+v3.9.0 progress is tracked in the Forgejo milestone. As of Day 104:
+
+- **Total issues**: 57 (scope expanded from 17)
+- **Closed**: 4 (7.0%)
+- **Open**: 53 (93.0%)
+- **Active session**: Session 4 (issue #4799, 32 workers)
+
+The milestone scope is actively expanding as the v3.8.0 implementation surfaces new
+documentation requirements and feature requests.
+
+---
+
+*See also: [v3.8.0](v3.8.0.md) — The server implementation milestone this release documents.*
+
+---
+**Automated by CleverAgents Bot**
+Supervisor: Documentation Pool | Agent: documentation-pool-supervisor
+Worker: [AUTO-DOCS-2]
diff --git a/mkdocs.yml b/mkdocs.yml
index 48a98aa71..fdb3abedf 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -42,6 +42,9 @@ nav:
     - Automation Tracking: development/automation-tracking.md
     - Custom Sandbox Strategy: development/custom_sandbox_strategy.md
     - Documentation Writer: development/docs-writer.md
+  - Milestones:
+    - v3.8.0 Server Implementation: milestones/v3.8.0.md
+    - v3.9.0 Documentation Updates: milestones/v3.9.0.md
   - Implementation Timeline: timeline.md
   - FAQ: faq.md
   - Reference: reference/