Merge pull request #2142 from Jdubrick/add-mcp-synthesizer

RHIDP-14069: add mcp tools to unified config

Author: tisnik

docs/config.md

@@ -827,6 +827,13 @@ Per Decision S5 of the design spike, backend-agnostic high-level sections
 only the Llama-Stack-specific synthesis controls: which baseline to start
 from, an optional profile file, and a raw native_override escape hatch.
 
+During synthesis from the default baseline or a profile, LCORE ensures the
+Llama Stack MCP tool_runtime provider (`provider_id: model-context-protocol`,
+`provider_type: remote::model-context-protocol`) is present so static
+`mcp_servers` and dynamic MCP registration work. That ensure is skipped when
+`baseline: empty` (migration / blank-slate); supply MCP via `native_override`
+in that case.
+
 Attributes:
     baseline: Synthesis starting point. "default" begins from LCORE's
         built-in baseline (src/data/default_run.yaml); "empty" begins from

docs/deployment_guide.md

@@ -105,8 +105,11 @@ starts from a *baseline*. By default that is LCORE's built-in baseline; a
 
 A profile is an ordinary `run.yaml`-shaped YAML file — the same schema Llama
 Stack reads natively. Everything else in the unified pipeline (enrichment,
-the high-level `inference.providers` section, `native_override`) is applied
-*on top* of the profile, in that order.
+the high-level `inference.providers` section, ensuring the MCP tool_runtime
+provider, then `native_override`) is applied *on top* of the profile, in that
+order. The MCP ensure adds `provider_id: model-context-protocol` when missing
+so static `mcp_servers` and dynamic MCP registration work; it is skipped only
+for `baseline: empty` (use `native_override` there if you need MCP).
 
 **Authoring a profile.** Start from one of the reference profiles shipped in
 [`examples/profiles/`](https://github.com/lightspeed-core/lightspeed-stack/tree/main/examples/profiles):

src/constants.py

@@ -160,6 +160,10 @@
 MCP_AUTH_CLIENT: Final[str] = "client"
 MCP_AUTH_OAUTH: Final[str] = "oauth"
 
+# MCP tool_runtime provider (Llama Stack run.yaml / unified synthesis)
+MCP_TOOL_RUNTIME_PROVIDER_ID: Final[str] = "model-context-protocol"
+MCP_TOOL_RUNTIME_PROVIDER_TYPE: Final[str] = "remote::model-context-protocol"
+
 # Media type constants for streaming responses
 MEDIA_TYPE_JSON: Final[str] = "application/json"
 MEDIA_TYPE_TEXT: Final[str] = "text/plain"

src/data/default_run.yaml

@@ -9,7 +9,9 @@
 # It is intentionally thinner than the repo-root run.yaml: it carries only the
 # APIs and providers needed to boot a minimal, queryable stack (inference,
 # safety, vector_io, agents, tool_runtime, files) plus the storage backends
-# those providers reference. Operators extend it via high-level sections or
+# those providers reference. tool_runtime includes rag-runtime (file_search /
+# RAG) and model-context-protocol (MCP) so those capabilities work when
+# operators enable them. Operators extend it via high-level sections or
 # `native_override`.
 #
 # NOTE: `external_providers_dir` carries a default (`:=~/.llama/providers.d`)
@@ -54,6 +56,9 @@ providers:
   - config: {}
     provider_id: rag-runtime
     provider_type: inline::rag-runtime
+  - config: {}
+    provider_id: model-context-protocol
+    provider_type: remote::model-context-protocol
   vector_io:
   - config:
       persistence:

src/llama_stack_configuration.py

@@ -782,6 +782,47 @@ def apply_high_level_inference(
     )
 
 
+def ensure_mcp_tool_runtime(ls_config: dict[str, Any]) -> None:
+    """Ensure the default MCP tool_runtime provider exists in ``ls_config``.
+
+    Adds ``tool_runtime`` to ``apis`` when missing, then appends the default
+    ``model-context-protocol`` provider under ``providers.tool_runtime`` when
+    no entry with that ``provider_id`` is already present. Existing entries
+    (including ``rag-runtime``) are left untouched.
+
+    Parameters:
+        ls_config: The Llama Stack configuration being synthesized (modified
+            in place).
+
+    Returns:
+        None: ``ls_config`` is modified in place.
+    """
+    apis = ls_config.setdefault("apis", [])
+    if "tool_runtime" not in apis:
+        apis.append("tool_runtime")
+
+    providers_section = ls_config.setdefault("providers", {})
+    tool_runtime = providers_section.setdefault("tool_runtime", [])
+    for existing in tool_runtime:
+        if (
+            isinstance(existing, dict)
+            and existing.get("provider_id") == constants.MCP_TOOL_RUNTIME_PROVIDER_ID
+        ):
+            return
+
+    tool_runtime.append(
+        {
+            "provider_id": constants.MCP_TOOL_RUNTIME_PROVIDER_ID,
+            "provider_type": constants.MCP_TOOL_RUNTIME_PROVIDER_TYPE,
+            "config": {},
+        }
+    )
+    logger.info(
+        "Added MCP tool_runtime provider provider_id=%r",
+        constants.MCP_TOOL_RUNTIME_PROVIDER_ID,
+    )
+
+
 def _resolve_profile_path(profile: str, config_file_dir: Optional[str]) -> Path:
     """Resolve a ``profile:`` path against the loaded config's directory (R8).
 
@@ -812,8 +853,9 @@ def synthesize_configuration(
     Implements the unified-mode synthesis pipeline: select a baseline (profile
     file, empty, or the built-in default), apply the existing enrichment
     (Azure Entra ID, BYOK RAG, Solr/OKP) for parity with legacy mode (R7),
-    expand the high-level ``inference.providers`` section, and deep-merge the
-    raw ``native_override`` last (R5).
+    expand the high-level ``inference.providers`` section, ensure the default
+    MCP tool_runtime provider when the baseline was not empty, and deep-merge
+    the raw ``native_override`` last (R5).
 
     Parameters:
         lcs_config: The full ``lightspeed-stack.yaml`` parsed into a dict.
@@ -829,13 +871,15 @@ def synthesize_configuration(
     unified = llama_stack.get("config")  # None when only top-level inputs are set
 
     # 1-2. Select the baseline.
+    baseline_was_empty = False
     if unified and unified.get("profile"):
         profile_path = _resolve_profile_path(unified["profile"], config_file_dir)
         logger.info("Loading synthesis baseline from profile %s", profile_path)
         with open(profile_path, "r", encoding="utf-8") as file:
             baseline = yaml.safe_load(file) or {}
     elif unified and unified.get("baseline") == "empty":
         logger.info("Synthesizing from an empty baseline")
+        baseline_was_empty = True
         baseline = {}
     else:
         baseline = (
@@ -860,11 +904,16 @@ def synthesize_configuration(
     if inference.get("providers"):
         apply_high_level_inference(ls_config, inference)
 
-    # 6. Raw escape hatch, deep-merged last with list replacement (R5).
+    # 6. Ensure MCP tool_runtime for default/profile baselines (skipped for
+    #    baseline: empty so migrate round-trips stay lossless).
+    if not baseline_was_empty:
+        ensure_mcp_tool_runtime(ls_config)
+
+    # 7. Raw escape hatch, deep-merged last with list replacement (R5).
     if unified and unified.get("native_override"):
         ls_config = deep_merge_list_replace(ls_config, unified["native_override"])
 
-    # 7. Dedupe again in case native_override or enrichment reintroduced dupes.
+    # 8. Dedupe again in case native_override or enrichment reintroduced dupes.
     dedupe_providers_vector_io(ls_config)
 
     return ls_config

tests/e2e/configuration/README.md

@@ -25,7 +25,10 @@ and the active `lightspeed-stack.yaml` is also copied to the repo root — so th
 relative `profile:` path resolves to that materialized file, which the unified
 synthesizer consumes as its baseline. LS behavior is identical to the legacy
 two-file path (requirement R7 in the config-merge design doc); the wiring that
-selects a provider config stays unchanged.
+selects a provider config stays unchanged. The synthesizer also ensures the
+MCP `tool_runtime` provider (`model-context-protocol`) is present on the
+profile baseline when missing; many `run-*.yaml` fixtures already include it,
+so the ensure is typically a no-op.
 
 The `tests/e2e/configs/run-*.yaml` files therefore serve a dual role: in
 server mode they are the run configuration of the standalone Llama Stack