refactor: isolate rpc server config composition

AGENTS.md

@@ -1,18 +1,29 @@
 # pitfalls / guide
 
+## extra fields
+
 prefer asserts actual['field'] == expected['field'] over assert actual == expected unless we know better (eg. no extra fields allowed)
 
+## tests
+
 Prefer pytest `tmp_path` for test-local filesystem state. Avoid fixed paths under `local_temp_root()` for tests that create durable files unless the test explicitly cleans or needs cross-process persistence; stale files there can change later test runs.
 
 Now that pytest-asyncio is installed, prefer `async def test_x()`
 instead of `def test_x(): async def scenario(): ...; asyncio.run(scenario())`
 
-more later
+## mgmt
+
+More packages please. we spent a while cleaning flatten packages/modules; putting files of similar interests in folders and sub-folders.
+example: some of tests/ and some packages. (simple example: src/pack/foo_bar.py -> src/pack/foo/bar.py)
+
+Lets just do that from the start this time, ok?
 
 ## Docs mgmt
 
 read docs/AGENTS.md
 
+more later
+
 # Test suite
 
 ```bash

docs/current_roadmap.md

@@ -191,6 +191,8 @@ implementation state.
     import-direction guard. The durable fix is not a permanent split launcher;
     it is making `wf_config` wide enough that the RPC server can compose from
     neutral config while MCP-specific adapters stay selected by source kind.
+    Completed: `wf_transport_rpc_http` no longer imports `wf_mcp`; server
+    composition from neutral or legacy MCP config lives behind `wf_server.config`.
   - Legacy config migration: add a converter from old `wf_mcp.config.json`
     (`store_root`, `connections[]`) into the wider `wf_config` shape
     (`server.store`, `server.sources[]`). `server.store` is already a
@@ -217,6 +219,13 @@ implementation state.
     upstream credentials, and surface missing auth as validation diagnostics.
   - Run watch/progress: start with polling over existing inspect/trace APIs;
     defer SSE/WebSocket/MCP progress until the polling UX is proven insufficient.
+  - MCP package split direction: keep separating "MCP as a client transport"
+    from "MCP as an upstream workflow source provider." The future shape is
+    likely `wf_transport_mcp` for exposing workflow/admin surfaces to MCP
+    clients, and `wf_sources_mcp` for discovering/invoking upstream MCP servers
+    as workflow capabilities. The current `wf_mcp` package still contains both
+    roles plus compatibility entrypoints; new server/transport work should avoid
+    depending on that combined facade.
 - Cleanup candidate: consolidate store/source registry id validation patterns
       (`SOURCE_REGISTRY_ID_PATTERN`, `STORE_ID_PATTERN`) only after another package
       needs the same rule. Today they intentionally stay close to their stores.

docs/superpowers/plans/2026-06-05-rpc-transport-config-boundary-cleanup.md

@@ -0,0 +1,543 @@
+# RPC Transport Config Boundary Cleanup Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Remove direct `wf_mcp` imports from `wf_transport_rpc_http` now that neutral `wf_config.server.sources[]` can describe MCP sources.
+
+**Architecture:** Keep JSON-RPC transport modules focused on serving a `WorkflowServer`. Move config-to-server composition into a server-layer module that can select local/static or MCP-backed composition by config source kind. `wf_server.context` remains MCP-free; the new config composition module is the explicit boundary for source-provider selection.
+
+**Tech Stack:** Typer CLI, `wf_config.WorkflowConfigFile`, `wf_server.WorkflowServer`, existing MCP-backed builder in `wf_mcp.broker.server`, AST import-direction tests.
+
+---
+
+## File Structure
+
+- Create `src/wf_server/config.py`: server composition from neutral workflow config and legacy MCP config path.
+- Modify `src/wf_transport_rpc_http/cli.py`: import server composition helpers from `wf_server.config`, not `wf_mcp.broker`.
+- Modify `tests/wf_transport_rpc_http/test_cli.py`: monkeypatch new helper paths.
+- Modify `tests/wf_transport_rpc_http/test_import_direction.py`: no change expected; it should pass once direct imports are removed.
+- Create `tests/wf_server/test_config_composition.py`: cover local/static and MCP-source selection.
+- Modify docs after implementation.
+
+## Current Context
+
+`src/wf_transport_rpc_http/cli.py` currently imports:
+
+```python
+from wf_mcp.broker import (
+    build_workflow_server_from_config,
+    build_workflow_server_from_workflow_config,
+    load_broker_config,
+)
+```
+
+That makes `tests/wf_transport_rpc_http/test_import_direction.py` fail:
+
+```python
+def test_wf_transport_rpc_http_imports_no_wfmcp_modules() -> None:
+    ...
+    assert violations == []
+```
+
+Do not remove the test. The transport package should not import MCP modules directly.
+
+`src/wf_server/context.py` has a narrower guard in `tests/wf_server/test_local_static_server.py` that only checks `context.py` for `WfMcpService`. Keep `context.py` untouched.
+
+## Task 1: Add Server Composition Tests
+
+**Files:**
+- Create: `tests/wf_server/test_config_composition.py`
+
+- [ ] **Step 1: Create test file**
+
+Create `tests/wf_server/test_config_composition.py`:
+
+```python
+from __future__ import annotations
+
+from wf_config import WorkflowConfigFile
+from wf_server.config import (
+    build_workflow_server_from_legacy_mcp_config,
+    build_workflow_server_from_workflow_config,
+)
+from wf_server.context import WorkflowServer
+
+
+def test_build_workflow_server_from_workflow_config_uses_local_static_for_no_mcp_sources(
+    tmp_path,
+) -> None:
+    config = WorkflowConfigFile.model_validate(
+        {
+            "version": 1,
+            "server": {
+                "store": {"kind": "filesystem", "root": str(tmp_path / "store")},
+                "sources": [{"kind": "stdlib", "id": "wf.std"}],
+            },
+        }
+    )
+
+    server = build_workflow_server_from_workflow_config(config)
+
+    assert isinstance(server, WorkflowServer)
+    assert server.config.store_root == tmp_path / "store"
+    assert server.source_registry_admin is None
+
+
+def test_build_workflow_server_from_workflow_config_uses_mcp_builder_for_mcp_sources(
+    monkeypatch, tmp_path
+) -> None:
+    captured = {}
+
+    def fake_builder(config):
+        captured["source_kinds"] = [source.kind for source in config.server.sources]
+        return "mcp-server"
+
+    monkeypatch.setattr(
+        "wf_server.config._build_mcp_workflow_server_from_workflow_config",
+        fake_builder,
+    )
+    config = WorkflowConfigFile.model_validate(
+        {
+            "version": 1,
+            "server": {
+                "store": {"kind": "filesystem", "root": str(tmp_path / "store")},
+                "sources": [
+                    {
+                        "kind": "mcp",
+                        "id": "everything.default",
+                        "provider": "everything",
+                        "account": "default",
+                        "transport": {"kind": "stdio", "command": "uvx"},
+                    }
+                ],
+            },
+        }
+    )
+
+    server = build_workflow_server_from_workflow_config(config)
+
+    assert server == "mcp-server"
+    assert captured["source_kinds"] == ["mcp"]
+
+
+def test_build_workflow_server_from_legacy_mcp_config_delegates_to_mcp_builder(
+    monkeypatch, tmp_path
+) -> None:
+    captured = {}
+
+    def fake_builder(path):
+        captured["path"] = path
+        return "legacy-mcp-server"
+
+    monkeypatch.setattr(
+        "wf_server.config._build_mcp_workflow_server_from_legacy_config",
+        fake_builder,
+    )
+    legacy_path = tmp_path / "wf_mcp.config.json"
+    legacy_path.write_text('{"store_root": "store", "connections": []}', encoding="utf-8")
+
+    server = build_workflow_server_from_legacy_mcp_config(legacy_path)
+
+    assert server == "legacy-mcp-server"
+    assert captured["path"] == legacy_path
+```
+
+- [ ] **Step 2: Run tests and verify failure**
+
+Run:
+
+```bash
+uv run pytest tests/wf_server/test_config_composition.py -q
+```
+
+Expected: fail because `wf_server.config` does not exist.
+
+## Task 2: Implement Server Config Composition Module
+
+**Files:**
+- Create: `src/wf_server/config.py`
+
+- [ ] **Step 1: Create module**
+
+Create `src/wf_server/config.py`:
+
+```python
+from __future__ import annotations
+
+from pathlib import Path
+
+from wf_config import FilesystemStoreConfig, WorkflowConfigFile
+
+from .context import WorkflowServer, build_local_static_workflow_server
+
+
+def _has_mcp_sources(config: WorkflowConfigFile) -> bool:
+    return any(getattr(source, "kind", None) == "mcp" for source in config.server.sources)
+
+
+def _build_mcp_workflow_server_from_workflow_config(
+    config: WorkflowConfigFile,
+) -> WorkflowServer:
+    """Build an MCP-backed server from neutral config.
+
+    This import is intentionally isolated here: transport packages should not
+    import MCP modules, while this server composition boundary is allowed to
+    select source-provider implementations by source kind.
+    """
+    from wf_mcp.broker import build_workflow_server_from_workflow_config
+
+    return build_workflow_server_from_workflow_config(config)
+
+
+def _build_mcp_workflow_server_from_legacy_config(path: Path) -> WorkflowServer:
+    """Build an MCP-backed server from legacy broker config."""
+    from wf_mcp.broker import build_workflow_server_from_config, load_broker_config
+
+    return build_workflow_server_from_config(load_broker_config(path))
+
+
+def build_workflow_server_from_workflow_config(
+    config: WorkflowConfigFile,
+) -> WorkflowServer:
+    """Build a WorkflowServer from neutral workflow config.
+
+    Local/static configs use built-in sources. Configs with `kind: "mcp"`
+    sources delegate to the MCP provider adapter.
+    """
+    if _has_mcp_sources(config):
+        return _build_mcp_workflow_server_from_workflow_config(config)
+    store = config.server.store
+    if not isinstance(store, FilesystemStoreConfig):
+        raise ValueError("wf-rpc-server currently requires filesystem store")
+    return build_local_static_workflow_server(store.root)
+
+
+def build_workflow_server_from_legacy_mcp_config(path: str | Path) -> WorkflowServer:
+    """Build a WorkflowServer from legacy wf_mcp.config.json.
+
+    Prefer neutral `wf_config` for new setups. This compatibility hook keeps the
+    transport CLI free of direct MCP imports while existing users migrate.
+    """
+    return _build_mcp_workflow_server_from_legacy_config(Path(path))
+```
+
+- [ ] **Step 2: Run tests**
+
+Run:
+
+```bash
+uv run pytest tests/wf_server/test_config_composition.py -q
+```
+
+Expected: pass.
+
+- [ ] **Step 3: Run import-boundary check**
+
+Run:
+
+```bash
+uv run pytest tests/wf_server/test_local_static_server.py::test_wf_server_context_imports_no_wfmcp_service -q
+```
+
+Expected: pass because `context.py` was not changed.
+
+## Task 3: Update RPC CLI to Use Server Composition Helpers
+
+**Files:**
+- Modify: `src/wf_transport_rpc_http/cli.py`
+- Modify: `tests/wf_transport_rpc_http/test_cli.py`
+
+- [ ] **Step 1: Update imports**
+
+Replace:
+
+```python
+from wf_mcp.broker import (
+    build_workflow_server_from_config,
+    build_workflow_server_from_workflow_config,
+    load_broker_config,
+)
+
+from wf_server import build_local_static_workflow_server
+```
+
+with:
+
+```python
+from wf_server.config import (
+    build_workflow_server_from_legacy_mcp_config,
+    build_workflow_server_from_workflow_config,
+)
+from wf_server.context import build_local_static_workflow_server
+```
+
+- [ ] **Step 2: Update legacy mcp config branch**
+
+Replace:
+
+```python
+    if mcp_config is not None:
+        broker_config = load_broker_config(mcp_config)
+        server = build_workflow_server_from_config(broker_config)
+```
+
+with:
+
+```python
+    if mcp_config is not None:
+        server = build_workflow_server_from_legacy_mcp_config(mcp_config)
+```
+
+- [ ] **Step 3: Remove duplicated mcp source detection from CLI**
+
+Inside the `if config is not None:` block, remove:
+
+```python
+        has_mcp_sources = any(
+            getattr(source, "kind", None) == "mcp"
+            for source in workflow_config.server.sources
+        )
+        if server is None and has_mcp_sources:
+            server = build_workflow_server_from_workflow_config(workflow_config)
+```
+
+Then replace the local/static store handling block:
+
+```python
+        store = workflow_config.server.store
+        if server is None and not isinstance(store, FilesystemStoreConfig):
+            raise typer.BadParameter(
+                "wf-rpc-server currently requires filesystem store"
+            )
+        if server is None:
+            resolved_store_root = resolved_store_root or store.root
+```
+
+with:
+
+```python
+        store = workflow_config.server.store
+        if server is None and store_root is None:
+            server = build_workflow_server_from_workflow_config(workflow_config)
+        elif server is None:
+            if not isinstance(store, FilesystemStoreConfig):
+                raise typer.BadParameter(
+                    "wf-rpc-server currently requires filesystem store"
+                )
+            resolved_store_root = resolved_store_root or store.root
+```
+
+Keep `--store-root` as an override for local/static configs. `--store-root` is still forbidden with `--mcp-config`; do not add new behavior there.
+
+- [ ] **Step 4: Update tests monkeypatch paths**
+
+In `tests/wf_transport_rpc_http/test_cli.py`, update existing monkeypatches to
+match the new boundary.
+
+For `test_rpc_server_cli_uses_configured_store_and_transport`, stop monkeypatching
+`build_local_static_workflow_server`; the CLI now delegates config-based server
+composition to `build_workflow_server_from_workflow_config`.
+
+Replace:
+
+```python
+def fake_build_server(root):
+    captured["store_root"] = root
+    return object()
+```
+
+with:
+
+```python
+def fake_build_server(config):
+    captured["store_root"] = config.server.store.root
+    return object()
+```
+
+Replace this monkeypatch:
+
+```python
+monkeypatch.setattr(
+    "wf_transport_rpc_http.cli.build_local_static_workflow_server",
+    fake_build_server,
+)
+```
+
+with:
+
+```python
+monkeypatch.setattr(
+    "wf_transport_rpc_http.cli.build_workflow_server_from_workflow_config",
+    fake_build_server,
+)
+```
+
+Keep the assertion:
+
+```python
+assert captured["store_root"] == (tmp_path / ".wf_store").resolve()
+```
+
+For legacy MCP config tests, replace monkeypatch paths:
+
+```python
+"wf_transport_rpc_http.cli.build_workflow_server_from_config"
+"wf_transport_rpc_http.cli.build_workflow_server_from_workflow_config"
+```
+
+with:
+
+```python
+"wf_transport_rpc_http.cli.build_workflow_server_from_legacy_mcp_config"
+"wf_transport_rpc_http.cli.build_workflow_server_from_workflow_config"
+```
+
+If a test currently monkeypatches `load_broker_config`, remove that monkeypatch and have the fake legacy builder capture the config path directly.
+
+For `test_rpc_server_cli_uses_mcp_config_server`, replace the two fake helpers:
+
+```python
+def fake_load_broker_config(path):
+    captured["mcp_config_path"] = path
+    return "broker-config"
+
+def fake_build_mcp_server(config):
+    captured["mcp_config"] = config
+    return object()
+```
+
+with one helper:
+
+```python
+def fake_build_mcp_server(path):
+    captured["mcp_config_path"] = path
+    return object()
+```
+
+Replace the two monkeypatches:
+
+```python
+monkeypatch.setattr("wf_transport_rpc_http.cli.load_broker_config", fake_load_broker_config)
+monkeypatch.setattr(
+    "wf_transport_rpc_http.cli.build_workflow_server_from_config",
+    fake_build_mcp_server,
+)
+```
+
+with:
+
+```python
+monkeypatch.setattr(
+    "wf_transport_rpc_http.cli.build_workflow_server_from_legacy_mcp_config",
+    fake_build_mcp_server,
+)
+```
+
+Remove the assertion:
+
+```python
+assert captured["mcp_config"] == "broker-config"
+```
+
+- [ ] **Step 5: Run CLI tests**
+
+Run:
+
+```bash
+uv run pytest tests/wf_transport_rpc_http/test_cli.py -q
+```
+
+Expected: pass.
+
+## Task 4: Restore Transport Import-Direction Guard
+
+**Files:**
+- Test: `tests/wf_transport_rpc_http/test_import_direction.py`
+
+- [ ] **Step 1: Run guard**
+
+Run:
+
+```bash
+uv run pytest tests/wf_transport_rpc_http/test_import_direction.py -q
+```
+
+Expected: pass. If it fails, inspect `src/wf_transport_rpc_http` for any remaining `wf_mcp` imports and remove them.
+
+- [ ] **Step 2: Run wider RPC subset**
+
+Run:
+
+```bash
+uv run pytest tests/wf_transport_rpc_http tests/wf_cli/test_remote_target.py -q
+```
+
+Expected: pass. The prior known failure should be gone.
+
+## Task 5: Update Docs and Mark Cleanup Complete
+
+**Files:**
+- Modify: `docs/current_roadmap.md`
+- Modify: `docs/superpowers/specs/2026-06-03-long-lived-workflow-api-boundary.md`
+
+- [ ] **Step 1: Update roadmap**
+
+In `docs/current_roadmap.md`, under "Transport package boundary cleanup", append:
+
+```markdown
+    Completed: `wf_transport_rpc_http` no longer imports `wf_mcp`; server
+    composition from neutral or legacy MCP config lives behind `wf_server.config`.
+```
+
+- [ ] **Step 2: Update long-lived API spec**
+
+In `docs/superpowers/specs/2026-06-03-long-lived-workflow-api-boundary.md`, under "Transport package boundary cleanup", append:
+
+```markdown
+   Completed when `tests/wf_transport_rpc_http/test_import_direction.py` passes
+   and the RPC transport CLI imports only `wf_config`, `wf_server`, and transport
+   modules for server construction.
+```
+
+## Task 6: Final Verification and Commit
+
+**Files:**
+- All touched files.
+
+- [ ] **Step 1: Run focused tests**
+
+Run:
+
+```bash
+uv run pytest tests/wf_server/test_config_composition.py tests/wf_transport_rpc_http tests/wf_cli/test_remote_target.py -q
+```
+
+Expected: pass.
+
+- [ ] **Step 2: Run lint/type checks**
+
+Run:
+
+```bash
+uv run ruff check src/wf_server src/wf_transport_rpc_http tests/wf_server tests/wf_transport_rpc_http
+uv run basedpyright --level error src/wf_server src/wf_transport_rpc_http tests/wf_server tests/wf_transport_rpc_http
+```
+
+Expected: pass with 0 errors.
+
+- [ ] **Step 3: Commit**
+
+Run:
+
+```bash
+git add src/wf_server src/wf_transport_rpc_http tests/wf_server tests/wf_transport_rpc_http docs/current_roadmap.md docs/superpowers/specs/2026-06-03-long-lived-workflow-api-boundary.md
+git commit -m "refactor: isolate rpc server config composition"
+```
+
+## Self-Review Checklist
+
+- `src/wf_transport_rpc_http` contains no direct `wf_mcp` imports.
+- `src/wf_server/context.py` remains MCP-free.
+- The MCP-specific import is isolated in `src/wf_server/config.py` with a docstring explaining the boundary.
+- `wf-rpc-server --config` still works for local/static and MCP-source neutral configs.
+- `wf-rpc-server --mcp-config` still works as a legacy compatibility path.

docs/superpowers/specs/2026-06-03-long-lived-workflow-api-boundary.md

@@ -54,6 +54,19 @@ wf_mcp
   MCP transport and upstream MCP integration
 ```
 
+`wf_mcp` is intentionally treated as a combined compatibility package in this
+diagram, not as the desired final boundary. It currently contains two different
+roles:
+
+- MCP as a client transport: an MCP client connects to workflow/admin surfaces.
+- MCP as an upstream source provider: workflows discover and invoke external MCP
+  servers as capability sources.
+
+Those roles should separate over time. A future `wf_transport_mcp` can expose
+the same `WorkflowServer` / `wf_api` surfaces to MCP clients, while a future
+`wf_sources_mcp` can own upstream MCP discovery, sessions, tool invocation,
+resource/prompt access, and FastMCP-specific provider behavior.
+
 `wf_transport_rpc_http` should call `WorkflowApi` through the server
 composition. It should not call `WfMcpService`.
 
@@ -252,6 +265,10 @@ Hard rules:
   MCP-specific context adapter.
 - A future MCP transport mounted through `wf_server` must still keep upstream
   MCP source execution separate from transport request handling.
+- Do not add new generic server or transport code that depends on the combined
+  `wf_mcp` facade. If it needs MCP-specific upstream behavior, isolate that as a
+  source-provider adapter; if it needs to expose workflow operations to MCP
+  clients, isolate that as a transport adapter.
 
 If a reusable service currently lives under `wf_mcp.broker.service` but has no
 MCP dependency, later slices may move or duplicate a protocol-neutral version.
@@ -368,6 +385,19 @@ Possible providers:
 This slice should avoid making "source" mean "MCP connection." MCP is one
 source provider, not the source model.
 
+Future package direction:
+
+```text
+wf_transport_mcp
+  exposes WorkflowServer / wf_api operations to MCP clients
+
+wf_sources_mcp
+  consumes upstream MCP servers as workflow capability sources
+
+wf_mcp
+  compatibility package until old MCP entrypoints can shrink or retire
+```
+
 Current MCP-backed server status:
 
 - MCP-backed `WorkflowServer` construction is implemented.
@@ -398,6 +428,9 @@ Next implementation slices should be:
    transport-only. After `wf_config` can describe MCP sources, `wf-rpc-server
    --config ...` should compose MCP-backed sources from neutral config and the
    `--mcp-config` path can become deprecated/legacy.
+   Completed when `tests/wf_transport_rpc_http/test_import_direction.py` passes
+   and the RPC transport CLI imports only `wf_config`, `wf_server`, and transport
+   modules for server construction.
 3. Legacy MCP config migration. Provide an explicit converter from old
    `wf_mcp.config.json` into `WorkflowConfigFile`: `store_root` maps to
    `server.store` (`StoreConfig` is already a discriminated union; currently

docs/wf_mcp_architecture.md

@@ -158,9 +158,20 @@ gone.
 
 If this becomes multiple distributions, likely split points are:
 
-- `wf-mcp-proxy`: `proxy`, `control`, `shared`
-- `wf-mcp-broker`: `broker`, `storage`, `workflow`, `shared`
-- `wf-mcp-sdk`: `sdk`, `capabilities`, `models`, `shared`
+- `wf-transport-mcp`: MCP-facing transport that exposes neutral
+  `WorkflowServer` / `wf_api` workflow, source-admin, and platform-admin
+  surfaces to MCP clients.
+- `wf-sources-mcp`: upstream MCP source provider that owns external MCP server
+  discovery, sessions, tool invocation, resources/prompts, FastMCP integration,
+  and conversion of discovered MCP tools into workflow node specs.
+- `wf-mcp-proxy`: compatibility/proxy runtime for mounting upstream MCP servers
+  through FastMCP, if that remains useful after `wf-sources-mcp` exists.
 
-For now, keep one distribution and use import discipline to preserve those
-boundaries.
+The key boundary is direction, not naming: "MCP as a client transport" and
+"MCP as an upstream workflow source" are separate roles. The current `wf_mcp`
+package still contains both roles plus compatibility entrypoints. New
+server/transport code should depend on `wf_server` / `wf_api` surfaces and keep
+MCP-specific upstream behavior behind a source-provider adapter.
+
+For now, keep one distribution and use import discipline to preserve these
+future split points.

src/wf_server/config.py

@@ -0,0 +1,57 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+from wf_config import FilesystemStoreConfig, WorkflowConfigFile
+
+from .context import WorkflowServer, build_local_static_workflow_server
+
+
+def _has_mcp_sources(config: WorkflowConfigFile) -> bool:
+    return any(getattr(source, "kind", None) == "mcp" for source in config.server.sources)
+
+
+def _build_mcp_workflow_server_from_workflow_config(
+    config: WorkflowConfigFile,
+) -> WorkflowServer:
+    """Build an MCP-backed server from neutral config.
+
+    This import is intentionally isolated here: transport packages should not
+    import MCP modules, while this server composition boundary is allowed to
+    select source-provider implementations by source kind.
+    """
+    from wf_mcp.broker import build_workflow_server_from_workflow_config
+
+    return build_workflow_server_from_workflow_config(config)
+
+
+def _build_mcp_workflow_server_from_legacy_config(path: Path) -> WorkflowServer:
+    """Build an MCP-backed server from legacy broker config."""
+    from wf_mcp.broker import build_workflow_server_from_config, load_broker_config
+
+    return build_workflow_server_from_config(load_broker_config(path))
+
+
+def build_workflow_server_from_workflow_config(
+    config: WorkflowConfigFile,
+) -> WorkflowServer:
+    """Build a WorkflowServer from neutral workflow config.
+
+    Local/static configs use built-in sources. Configs with ``kind: "mcp"``
+    sources delegate to the MCP provider adapter.
+    """
+    if _has_mcp_sources(config):
+        return _build_mcp_workflow_server_from_workflow_config(config)
+    store = config.server.store
+    if not isinstance(store, FilesystemStoreConfig):
+        raise ValueError("wf-rpc-server currently requires filesystem store")
+    return build_local_static_workflow_server(store.root)
+
+
+def build_workflow_server_from_legacy_mcp_config(path: str | Path) -> WorkflowServer:
+    """Build a WorkflowServer from legacy wf_mcp.config.json.
+
+    Prefer neutral ``wf_config`` for new setups. This compatibility hook keeps the
+    transport CLI free of direct MCP imports while existing users migrate.
+    """
+    return _build_mcp_workflow_server_from_legacy_config(Path(path))

src/wf_transport_rpc_http/cli.py

@@ -11,13 +11,11 @@ from wf_config import (
     load_workflow_config,
 )
 
-from wf_mcp.broker import (
-    build_workflow_server_from_config,
+from wf_server.config import (
+    build_workflow_server_from_legacy_mcp_config,
     build_workflow_server_from_workflow_config,
-    load_broker_config,
 )
-
-from wf_server import build_local_static_workflow_server
+from wf_server.context import build_local_static_workflow_server
 
 from .app import create_rpc_app
 
@@ -65,23 +63,26 @@ def serve(
 
     server = None
     if mcp_config is not None:
-        broker_config = load_broker_config(mcp_config)
-        server = build_workflow_server_from_config(broker_config)
+        server = build_workflow_server_from_legacy_mcp_config(mcp_config)
 
     if config is not None:
         workflow_config = load_workflow_config(config)
-        has_mcp_sources = any(
-            getattr(source, "kind", None) == "mcp"
-            for source in workflow_config.server.sources
-        )
-        if server is None and has_mcp_sources:
-            server = build_workflow_server_from_workflow_config(workflow_config)
         store = workflow_config.server.store
-        if server is None and not isinstance(store, FilesystemStoreConfig):
-            raise typer.BadParameter(
-                "wf-rpc-server currently requires filesystem store"
+        if server is None and store_root is None:
+            server = build_workflow_server_from_workflow_config(workflow_config)
+        elif server is None:
+            has_mcp_sources = any(
+                getattr(source, "kind", None) == "mcp"
+                for source in workflow_config.server.sources
             )
-        if server is None:
+            if has_mcp_sources:
+                raise typer.BadParameter(
+                    "--store-root cannot override MCP-source config"
+                )
+            if not isinstance(store, FilesystemStoreConfig):
+                raise typer.BadParameter(
+                    "wf-rpc-server currently requires filesystem store"
+                )
             resolved_store_root = resolved_store_root or store.root
         rpc_transport = next(
             (

tests/wf_server/test_config_composition.py

@@ -0,0 +1,87 @@
+from __future__ import annotations
+
+from wf_config import WorkflowConfigFile
+from wf_server.config import (
+    build_workflow_server_from_legacy_mcp_config,
+    build_workflow_server_from_workflow_config,
+)
+from wf_server.context import WorkflowServer
+
+
+def test_build_workflow_server_from_workflow_config_uses_local_static_for_no_mcp_sources(
+    tmp_path,
+) -> None:
+    config = WorkflowConfigFile.model_validate(
+        {
+            "version": 1,
+            "server": {
+                "store": {"kind": "filesystem", "root": str(tmp_path / "store")},
+                "sources": [{"kind": "stdlib", "id": "wf.std"}],
+            },
+        }
+    )
+
+    server = build_workflow_server_from_workflow_config(config)
+
+    assert isinstance(server, WorkflowServer)
+    assert server.config.store_root == tmp_path / "store"
+    assert server.source_registry_admin is None
+
+
+def test_build_workflow_server_from_workflow_config_uses_mcp_builder_for_mcp_sources(
+    monkeypatch, tmp_path
+) -> None:
+    captured = {}
+
+    def fake_builder(config):
+        captured["source_kinds"] = [source.kind for source in config.server.sources]
+        return "mcp-server"
+
+    monkeypatch.setattr(
+        "wf_server.config._build_mcp_workflow_server_from_workflow_config",
+        fake_builder,
+    )
+    config = WorkflowConfigFile.model_validate(
+        {
+            "version": 1,
+            "server": {
+                "store": {"kind": "filesystem", "root": str(tmp_path / "store")},
+                "sources": [
+                    {
+                        "kind": "mcp",
+                        "id": "everything.default",
+                        "provider": "everything",
+                        "account": "default",
+                        "transport": {"kind": "stdio", "command": "uvx"},
+                    }
+                ],
+            },
+        }
+    )
+
+    server = build_workflow_server_from_workflow_config(config)
+
+    assert server == "mcp-server"
+    assert captured["source_kinds"] == ["mcp"]
+
+
+def test_build_workflow_server_from_legacy_mcp_config_delegates_to_mcp_builder(
+    monkeypatch, tmp_path
+) -> None:
+    captured = {}
+
+    def fake_builder(path):
+        captured["path"] = path
+        return "legacy-mcp-server"
+
+    monkeypatch.setattr(
+        "wf_server.config._build_mcp_workflow_server_from_legacy_config",
+        fake_builder,
+    )
+    legacy_path = tmp_path / "wf_mcp.config.json"
+    legacy_path.write_text('{"store_root": "store", "connections": []}', encoding="utf-8")
+
+    server = build_workflow_server_from_legacy_mcp_config(legacy_path)
+
+    assert server == "legacy-mcp-server"
+    assert captured["path"] == legacy_path

tests/wf_transport_rpc_http/test_cli.py

@@ -70,8 +70,8 @@ def test_rpc_server_cli_uses_configured_store_and_transport(
     )
     captured: dict[str, object] = {}
 
-    def fake_build_server(root):
-        captured["store_root"] = root
+    def fake_build_server(config):
+        captured["store_root"] = config.server.store.root
         return object()
 
     def fake_create_rpc_app(server, *, rpc_path="/rpc"):
@@ -86,7 +86,7 @@ def test_rpc_server_cli_uses_configured_store_and_transport(
         captured["access_log"] = access_log
 
     monkeypatch.setattr(
-        "wf_transport_rpc_http.cli.build_local_static_workflow_server",
+        "wf_transport_rpc_http.cli.build_workflow_server_from_workflow_config",
         fake_build_server,
     )
     monkeypatch.setattr("wf_transport_rpc_http.cli.create_rpc_app", fake_create_rpc_app)
@@ -115,12 +115,8 @@ def test_rpc_server_cli_uses_mcp_config_server(monkeypatch, tmp_path) -> None:
     )
     captured: dict[str, object] = {}
 
-    def fake_load_broker_config(path):
+    def fake_build_mcp_server(path):
         captured["mcp_config_path"] = path
-        return "broker-config"
-
-    def fake_build_mcp_server(config):
-        captured["mcp_config"] = config
         return object()
 
     def fake_create_rpc_app(server, *, rpc_path="/rpc"):
@@ -134,9 +130,8 @@ def test_rpc_server_cli_uses_mcp_config_server(monkeypatch, tmp_path) -> None:
         captured["port"] = port
         captured["access_log"] = access_log
 
-    monkeypatch.setattr("wf_transport_rpc_http.cli.load_broker_config", fake_load_broker_config)
     monkeypatch.setattr(
-        "wf_transport_rpc_http.cli.build_workflow_server_from_config",
+        "wf_transport_rpc_http.cli.build_workflow_server_from_legacy_mcp_config",
         fake_build_mcp_server,
     )
     monkeypatch.setattr("wf_transport_rpc_http.cli.create_rpc_app", fake_create_rpc_app)
@@ -156,7 +151,6 @@ def test_rpc_server_cli_uses_mcp_config_server(monkeypatch, tmp_path) -> None:
 
     assert result.exit_code == 0, result.output
     assert captured["mcp_config_path"] == config_path
-    assert captured["mcp_config"] == "broker-config"
     assert captured["server"] is not None
     assert captured["rpc_path"] == "/rpc"
     assert captured["host"] == "127.0.0.9"
@@ -343,3 +337,35 @@ def test_rpc_server_cli_config_with_mcp_source_uses_mcp_builder(
     assert result.exit_code == 0, result.output
     assert captured["source_kinds"] == ["mcp"]
     assert captured["run"]["app"] == "app"
+
+
+def test_rpc_server_cli_rejects_store_root_with_mcp_source_config(tmp_path) -> None:
+    config_path = tmp_path / "wf.json"
+    config_path.write_text(
+        json.dumps(
+            {
+                "version": 1,
+                "server": {
+                    "store": {"kind": "filesystem", "root": ".wf_store"},
+                    "sources": [
+                        {
+                            "kind": "mcp",
+                            "id": "everything.default",
+                            "provider": "everything",
+                            "account": "default",
+                            "transport": {"kind": "stdio", "command": "uvx"},
+                        }
+                    ],
+                },
+            }
+        ),
+        encoding="utf-8",
+    )
+
+    result = CliRunner().invoke(
+        app,
+        ["--config", str(config_path), "--store-root", str(tmp_path / "override")],
+    )
+
+    assert result.exit_code != 0
+    assert "--store-root cannot override MCP-source config" in result.output