fix(adapter): mirror provider alias map onto YAML path (#12)

[FORCE-MERGE AUDIT — §SOP-7] hongming chat-go ("do both") in transcript ~03:54 UTC 2026-05-10. Closes provider-registry wedge that blocked all claude-code workspaces with NOT_CONFIGURED. Live-patched on staging-cplead-2 via SSM 03:46-ish; this is the durable bake-in. 81 tests pass + 3 new regression tests.

Dockerfile

@@ -43,6 +43,19 @@ RUN pip install --no-cache-dir -r requirements.txt && \
 # Copy adapter code
 COPY adapter.py .
 COPY __init__.py .
+# Provider registry. The adapter's _load_providers walks 4 paths:
+#   1. /opt/adapter/config.yaml          — provisioner-managed canonical
+#   2. os.path.dirname(__file__)/config.yaml  — alongside adapter.py (this image)
+#   3. ${WORKSPACE_CONFIG_PATH}/config.yaml   — workspace per-instance overrides
+#   4. _BUILTIN_PROVIDERS                — oauth + anthropic-api only
+# On this image /opt/adapter/ is never populated by the platform
+# provisioner, so path 2 (/app/config.yaml) is the load-bearing one.
+# Without this COPY the file isn't in the image, all 3 file paths fail,
+# and _load_providers falls through to _BUILTIN_PROVIDERS — every
+# MiniMax/GLM/Kimi/DeepSeek model silently routes to anthropic-oauth →
+# "Not logged in. Please run /login" at first LLM call. Caused the
+# canary's 38h chronic red on 2026-05-07/08 (molecule-core#129).
+COPY config.yaml .
 # Adapter-specific executor — owned by THIS template (universal-runtime
 # refactor, molecule-core task #87). Lives alongside adapter.py so
 # Python's import system picks the local /app/claude_sdk_executor.py

adapter.py

@@ -147,36 +147,118 @@ def _normalize_provider(entry: dict):
     }
 
 
+# Canonical install path the platform provisioner is contracted to clone
+# the template repo into. Hardcoded so the adapter's config.yaml lookup
+# is invariant across Docker (mounted /app→/opt/adapter) and EC2-host
+# (cloned by molecule-controlplane's ec2.go) install paths — robust
+# against the site-packages copy that bit us 2026-05-04 11:08Z.
+_CANONICAL_ADAPTER_DIR = "/opt/adapter"
+
+# Adjacent-to-adapter.py path. Module-level so tests can monkeypatch it
+# to redirect the path-2 lookup at a controlled tmp dir. Production code
+# resolves this once at import time and never touches it again — same
+# semantics as before.
+_TEMPLATE_DIR = os.path.dirname(os.path.abspath(__file__))
+
+
 def _load_providers(config_path: str) -> tuple:
-    """Load the provider registry from /configs/config.yaml.
+    """Load the provider registry from the template's bundled config.yaml.
 
-    The YAML's top-level ``providers:`` list is the canonical source —
+    The providers list is a TEMPLATE concern — it describes which
-    canvas Config tab reads the same list to populate its Provider
+    models/auth-modes this runtime image supports — and ships in the
-    dropdown so the UI and the adapter never disagree on what's
+    template's own config.yaml alongside adapter.py. The per-workspace
-    available. Falls back to ``_BUILTIN_PROVIDERS`` (oauth + anthropic-api)
+    ``${WORKSPACE_CONFIG_PATH}/config.yaml`` (default ``/configs/``)
-    if the file is missing, malformed, or has no providers section, so a
+    only contains workspace-specific overrides (model, runtime, skills,
-    bare-bones workspace still boots with the historical defaults.
+    prompt files) and does NOT carry a providers section.
 
-    Per-entry isolation: a single bad provider entry is dropped with a
+    Two-step incident history:
-    warning; the rest of the registry survives. Used to be a generator
+      • Pre-2026-05-04 09:00Z: only checked ``config_path``, fell back
-    inside tuple(...) that propagated any AttributeError out and reverted
+        to ``_BUILTIN_PROVIDERS`` (oauth + anthropic-api). Every
-    the whole registry to builtins — exactly the silent-fallback failure
+        MiniMax / GLM / Kimi / DeepSeek model resolved to
-    mode this file's existence was meant to fix.
+        ``anthropic-oauth`` and crashed at first LLM call with
+        "Not logged in. Please run /login". Fixed by adding a
+        template-bundled lookup using
+        ``os.path.dirname(os.path.abspath(__file__))``.
+      • 2026-05-04 11:08Z: that ``__file__`` lookup misses on EC2-host
+        installs because the provisioner copies adapter.py to
+        ``/opt/molecule-venv/lib/python3.12/site-packages/`` —
+        site-packages wins over PYTHONPATH=/opt/adapter (which the
+        host install doesn't set), so __file__ resolves to the venv
+        path WITHOUT an adjacent config.yaml. Same silent fallback
+        to anthropic-oauth + same "Not logged in" symptom.
+      • 2026-05-08 (#129): the multi-path lookup that fixed both of
+        the above was lost in a post-suspension migration cycle (the
+        Gitea main branch never carried the fix even though the
+        :latest image had it baked in from a prior build). Canary
+        chronic red for 38h before this commit restored the lookup.
+
+    Resolution order:
+      1. ``/opt/adapter/config.yaml`` — canonical provisioner-managed
+         install dir. Hardcoded because the platform contract is
+         "provisioner clones template repo into /opt/adapter"; this
+         is invariant across Docker (mounted /app→/opt/adapter) and
+         EC2-host (cloned by ec2.go) install paths. Robust against
+         site-packages copy.
+      2. Adjacent to ``adapter.__file__`` — works in dev/test where
+         the canonical path doesn't exist. Also covers the Docker
+         image's /app/config.yaml (bundled by Dockerfile #6).
+      3. Per-workspace ``${config_path}/config.yaml`` — fallback for
+         operator-shipped overrides on a private deployment that
+         wants a custom providers list.
+      4. ``_BUILTIN_PROVIDERS`` — oauth + anthropic-api defaults so a
+         bare-bones workspace still boots even with no config.yaml
+         anywhere.
+
+    Per-entry isolation: a single bad provider entry is dropped with
+    a warning; the rest of the registry survives.
     """
-    yaml_path = os.path.join(config_path, "config.yaml")
+    canonical_yaml = os.path.join(_CANONICAL_ADAPTER_DIR, "config.yaml")
+    template_yaml = os.path.join(_TEMPLATE_DIR, "config.yaml")
+    workspace_yaml = os.path.join(config_path, "config.yaml")
+    # Deduplicate while preserving order — _CANONICAL_ADAPTER_DIR and
+    # the __file__ dir collide in dev/test (when imported from
+    # /opt/adapter directly), and workspace_yaml may also collide if
+    # config_path == /opt/adapter in tests.
+    seen = set()
+    candidates = []
+    for path in (canonical_yaml, template_yaml, workspace_yaml):
+        if path not in seen:
+            seen.add(path)
+            candidates.append(path)
+
+    raw = None
+    chosen_path = None
     try:
         import yaml  # transitive dep via molecule-ai-workspace-runtime
-        with open(yaml_path, "r") as f:
+    except ImportError:
-            data = yaml.safe_load(f) or {}
+        logger.warning("providers: yaml import failed; using builtins")
-    except FileNotFoundError:
-        logger.info("providers: %s not found, using builtin defaults", yaml_path)
-        return _BUILTIN_PROVIDERS
-    except Exception as exc:  # noqa: BLE001 — defensive: never block boot on YAML
-        logger.warning("providers: failed to load from %s (%s); using builtins", yaml_path, exc)
         return _BUILTIN_PROVIDERS
 
-    raw = data.get("providers") if isinstance(data, dict) else None
+    for yaml_path in candidates:
-    if not isinstance(raw, list) or not raw:
+        try:
+            with open(yaml_path, "r") as f:
+                data = yaml.safe_load(f) or {}
+        except FileNotFoundError:
+            logger.info("providers: %s not found, trying next candidate", yaml_path)
+            continue
+        except Exception as exc:  # noqa: BLE001 — defensive: never block boot on YAML
+            logger.warning(
+                "providers: failed to load from %s (%s); trying next candidate",
+                yaml_path, exc,
+            )
+            continue
+
+        candidate_raw = data.get("providers") if isinstance(data, dict) else None
+        if isinstance(candidate_raw, list) and candidate_raw:
+            raw = candidate_raw
+            chosen_path = yaml_path
+            break
+
+    if raw is None:
+        logger.info(
+            "providers: no providers section found in %s; using builtin defaults",
+            " or ".join(candidates),
+        )
         return _BUILTIN_PROVIDERS
 
     parsed = []
@@ -190,11 +272,139 @@ def _load_providers(config_path: str) -> tuple:
             parsed.append(normalized)
 
     if not parsed:
-        logger.warning("providers: no valid entries in %s; using builtins", yaml_path)
+        logger.warning("providers: no valid entries in %s; using builtins", chosen_path)
         return _BUILTIN_PROVIDERS
+    logger.info("providers: loaded %d entries from %s", len(parsed), chosen_path)
     return tuple(parsed)
 
 
+# Aliases for `MODEL_PROVIDER` env values that should map to a registry
+# provider name. The persona env files use shorter / friendlier slugs
+# than the registry's canonical names — without this alias map a value
+# like ``MODEL_PROVIDER=claude-code`` would fall through to YAML-based
+# resolution and (when the YAML doesn't pin a provider) hit the
+# model-prefix matcher with the operator-picked MODEL, mis-routing a
+# lead workspace through MiniMax even though its CLAUDE_CODE_OAUTH_TOKEN
+# was clearly meant to be used.
+#
+# Maintain this list in sync with the persona env file convention:
+#   - ``claude-code``  → ``anthropic-oauth`` (Claude Code subscription path)
+#   - ``anthropic``    → ``anthropic-api``  (direct Anthropic API key)
+# Provider names already in the registry alias to themselves implicitly
+# (the ``in registry`` check catches them before this map is consulted).
+_PROVIDER_SLUG_ALIASES = {
+    "claude-code": "anthropic-oauth",
+    "anthropic": "anthropic-api",
+}
+
+
+def _resolve_model_and_provider_from_env(
+    yaml_model: str,
+    yaml_provider: str,
+    providers: tuple,
+) -> tuple:
+    """Reconcile model + provider from env vars vs YAML, with the persona-env
+    convention winning over the legacy ``MODEL_PROVIDER``-as-model-id usage.
+
+    The persona env files (``~/.molecule-ai/personas/<name>/env`` on the host,
+    sourced into each workspace container at provision time) declare TWO env
+    vars with distinct semantics:
+
+      * ``MODEL`` — the model id (e.g. ``MiniMax-M2.7-highspeed``, ``opus``).
+      * ``MODEL_PROVIDER`` — the provider slug (e.g. ``minimax``,
+        ``claude-code``, ``anthropic``).
+
+    The legacy ``workspace/config.py`` (in molecule-ai-workspace-runtime)
+    historically interpreted ``MODEL_PROVIDER`` as the *model id* — a name
+    chosen before there was a separate ``MODEL`` env var. When both env vars
+    are set with the persona convention, the legacy code reads
+    ``MODEL_PROVIDER=minimax`` into ``runtime_config.model``, which then
+    fails to match any registry prefix (``minimax-`` requires a hyphen
+    suffix) and silently falls through to providers[0] (``anthropic-oauth``).
+    OAuth-token-less workspaces then wedge at ``query.initialize()`` because
+    the claude CLI can't authenticate. This is the 2026-05-08 dev-tree
+    incident — 22/27 non-lead workspaces stuck in ``degraded``.
+
+    Resolution order (this function):
+      1. ``MODEL`` env var → picked_model. Authoritative when set; the
+         persona env always sets it alongside ``MODEL_PROVIDER`` so the
+         model id never has to be inferred.
+      2. ``MODEL_PROVIDER`` env var → explicit_provider, BUT only when the
+         value matches a known provider name in the registry. This guards
+         against the legacy case where some callers still set
+         ``MODEL_PROVIDER`` to a model id (e.g. canvas Save+Restart prior to
+         this fix). If the value isn't a registered provider name and YAML
+         didn't supply a model, treat it as a model id for back-compat.
+      3. YAML ``runtime_config.model`` / ``provider`` — used for any field
+         the env didn't supply. Carries the operator's canvas selection
+         on workspaces that haven't yet adopted the persona env shape.
+
+    Returns ``(picked_model, explicit_provider_name)``. Either may be
+    empty/None — the caller (``setup``) handles the empty cases via
+    ``_resolve_provider``'s registry fallback.
+    """
+    env_model = (os.environ.get("MODEL") or "").strip()
+    env_provider = (os.environ.get("MODEL_PROVIDER") or "").strip()
+    provider_names_lower = {p.get("name", "").lower() for p in providers}
+
+    # Detect whether MODEL_PROVIDER carries the persona-convention slug
+    # (provider name) vs. the legacy convention (model id). Persona-
+    # convention wins when the value matches a registered provider; we
+    # fall back to legacy interpretation only when it doesn't.
+    #
+    # First, apply the alias map so persona-friendly slugs like
+    # ``claude-code`` resolve to the canonical registry name
+    # ``anthropic-oauth``. Without this, a lead workspace's
+    # ``MODEL_PROVIDER=claude-code`` env would fall through to the model-
+    # prefix matcher, see ``MODEL=MiniMax-M2.7`` and mis-route to MiniMax
+    # even though the operator's intent (and the OAuth token they set)
+    # was the OAuth subscription path.
+    env_provider_resolved = _PROVIDER_SLUG_ALIASES.get(
+        env_provider.lower(), env_provider,
+    ) if env_provider else ""
+    env_provider_is_slug = (
+        bool(env_provider_resolved)
+        and env_provider_resolved.lower() in provider_names_lower
+    )
+
+    # Picked model resolution
+    if env_model:
+        picked_model = env_model
+    elif env_provider and not env_provider_is_slug:
+        # Legacy: MODEL_PROVIDER env carried the model id. Honor it so
+        # canvas Save+Restart workflows that predate this fix keep working.
+        picked_model = env_provider
+    else:
+        picked_model = yaml_model or ""
+
+    # Explicit provider resolution — env wins when it's a registered slug
+    # (after alias mapping), otherwise fall back to YAML.
+    #
+    # YAML aliasing: the molecule-runtime wheel (config.py) auto-derives
+    # ``runtime_config.provider`` from the YAML/default model slug — the
+    # default model ``anthropic:claude-opus-4-7`` yields ``anthropic`` as
+    # the inferred provider. Without applying the alias map here, that
+    # auto-derived ``anthropic`` slug fails registry lookup and the
+    # adapter raises ValueError ("provider='anthropic' but it is not in
+    # the providers registry"), wedging the workspace at boot. The alias
+    # map already handles this for the env-var path above; mirror the
+    # same treatment for the YAML path so the runtime-wheel default
+    # produces a registered provider name in both cases. Caught
+    # 2026-05-09 on staging-cplead-2 — every workspace booted with
+    # ``configuration_status=not_configured`` because the YAML provider
+    # ``anthropic`` was passed through verbatim instead of being aliased
+    # to ``anthropic-api``.
+    if env_provider_is_slug:
+        explicit_provider = env_provider_resolved
+    elif yaml_provider:
+        yp_lower = yaml_provider.lower()
+        explicit_provider = _PROVIDER_SLUG_ALIASES.get(yp_lower, yaml_provider)
+    else:
+        explicit_provider = None
+
+    return picked_model, explicit_provider
+
+
 def _strip_provider_prefix(model: str) -> str:
     """Strip LangChain-style "<provider>:<model>" prefix from a model id.
 
@@ -280,13 +490,28 @@ def _project_vendor_auth(provider: dict) -> None:
         return
 
 
-def _resolve_provider(model: str, providers: tuple) -> dict:
+def _resolve_provider(
+    model: str,
+    providers: tuple,
+    explicit_provider: str = None,
+) -> dict:
     """Return the provider entry matching this model id.
 
-    Match is case-insensitive: prefix wins over alias when both could
+    If ``explicit_provider`` is given (set via the ``provider:`` field in
-    apply. Unknown ids fall back to the first provider in the registry
+    workspace config.yaml or runtime_config), look up by name first. If the
-    (by convention, the OAuth/safest default — anthropic-oauth in both
+    named provider is not in the registry, RAISE ``ValueError`` with an
-    _BUILTIN_PROVIDERS and the shipped config.yaml).
+    actionable message — silent fallback to ``providers[0]`` is the bug
+    that motivated #180 (workspace operator picks ``provider: minimax``
+    in the canvas Config tab, the adapter ignores it, the Claude SDK
+    silently keeps using ``CLAUDE_CODE_OAUTH_TOKEN`` and the operator has
+    no way to tell from the canvas that their provider switch did
+    nothing).
+
+    Without an explicit name: match is case-insensitive, prefix wins over
+    alias when both could apply, and unknown ids fall back to the first
+    provider in the registry (by convention, the OAuth/safest default —
+    ``anthropic-oauth`` in both _BUILTIN_PROVIDERS and the shipped
+    config.yaml).
 
     Pre-condition: ``providers`` is non-empty. _load_providers always
     returns at least one entry (built-ins when YAML is missing or every
@@ -298,6 +523,44 @@ def _resolve_provider(model: str, providers: tuple) -> dict:
             "_load_providers must always return at least one entry "
             "(falling back to _BUILTIN_PROVIDERS when needed)"
         )
+
+    # Explicit provider name takes precedence — fail fast if it's not in
+    # the registry. Anything else would silently route the operator's
+    # picked provider through the wrong auth/base_url path. The error
+    # message tells them exactly which two paths fix it.
+    if explicit_provider:
+        ep_lower = explicit_provider.lower()
+        for provider in providers:
+            if provider["name"].lower() == ep_lower:
+                return provider
+        names = ", ".join(p["name"] for p in providers)
+        raise ValueError(
+            f"claude-code adapter: workspace config picks "
+            f"provider='{explicit_provider}' but it is not in the "
+            f"providers registry.\n"
+            f"\n"
+            f"Known providers: {names}\n"
+            f"\n"
+            f"Two ways to fix:\n"
+            f"  (a) Add '{explicit_provider}' to /configs/config.yaml as a "
+            f"providers: entry. Required keys:\n"
+            f"        providers:\n"
+            f"          - name: {explicit_provider}\n"
+            f"            auth_mode: third_party_anthropic_compat\n"
+            f"            base_url: https://...   # provider's Anthropic-compat endpoint\n"
+            f"            auth_env: [{explicit_provider.upper()}_API_KEY]\n"
+            f"            model_prefixes: [...]\n"
+            f"  (b) Switch the workspace runtime template to one that "
+            f"natively supports {explicit_provider} (CrewAI, LangGraph, or "
+            f"DeepAgents read provider/model from runtime_config and route "
+            f"directly without needing an Anthropic-compat shim).\n"
+            f"\n"
+            f"Note: claude-code SDK speaks the Anthropic API protocol. "
+            f"Providers that only expose OpenAI-compatible endpoints "
+            f"(MiniMax, GLM, Kimi, DeepSeek native APIs) need either an "
+            f"Anthropic-compat proxy in front, or option (b)."
+        )
+
     if not model:
         return providers[0]
     m = model.lower()
@@ -400,9 +663,52 @@ class ClaudeCodeAdapter(BaseAdapter):
         # validation + ANTHROPIC_BASE_URL routing from that single decision.
         rc = config.runtime_config
         if isinstance(rc, dict):
-            picked_model = rc.get("model") or "sonnet"
+            yaml_model = rc.get("model") or ""
+            yaml_provider_name = rc.get("provider") or ""
         else:
-            picked_model = getattr(rc, "model", None) or "sonnet"
+            yaml_model = getattr(rc, "model", None) or ""
+            yaml_provider_name = getattr(rc, "provider", None) or ""
+
+        # Also honor the top-level `provider:` field in /configs/config.yaml.
+        # The canvas Config-tab Provider dropdown writes there (not into
+        # runtime_config) on some legacy paths. Either source is canonical;
+        # whichever is set wins. Root cause of #180: the adapter used to
+        # ignore both, silently routing every non-Anthropic provider pick
+        # through anthropic-oauth.
+        if not yaml_provider_name:
+            yaml_path = os.path.join(config.config_path, "config.yaml")
+            try:
+                import yaml  # transitive dep via molecule-ai-workspace-runtime
+                with open(yaml_path, "r") as f:
+                    data = yaml.safe_load(f) or {}
+                if isinstance(data, dict):
+                    val = data.get("provider")
+                    if isinstance(val, str) and val.strip():
+                        yaml_provider_name = val.strip()
+            except FileNotFoundError:
+                pass
+            except Exception as exc:  # noqa: BLE001 — defensive: never block boot
+                logger.warning(
+                    "providers: failed to read top-level provider: from %s (%s); "
+                    "falling back to model-based resolution",
+                    yaml_path, exc,
+                )
+
+        # Reconcile env vars (persona convention: MODEL=<id>,
+        # MODEL_PROVIDER=<slug>) against YAML. Env wins over YAML — the
+        # persona env files are the canonical per-agent provider mapping
+        # (Phase 2 mapping 2026-05-08), and the workspace-runtime wheel's
+        # legacy ``MODEL_PROVIDER``-as-model-id reading would otherwise
+        # silently route non-leads to providers[0] = anthropic-oauth.
+        # Documented in detail at _resolve_model_and_provider_from_env.
+        picked_model, explicit_provider_name = _resolve_model_and_provider_from_env(
+            yaml_model=yaml_model,
+            yaml_provider=yaml_provider_name,
+            providers=providers,
+        )
+        if not picked_model:
+            picked_model = "sonnet"
+
         # NOTE: do NOT strip the provider prefix here. The pre-fix routing
         # behavior — `anthropic:claude-opus-4-7` falls through to
         # providers[0] (anthropic-oauth) when no model_prefixes match — is
@@ -411,7 +717,15 @@ class ClaudeCodeAdapter(BaseAdapter):
         # `anthropic-api` provider and the CLI then hangs at `initialize`
         # because ANTHROPIC_API_KEY isn't set. The strip belongs only at
         # the CLI invocation site (create_executor below).
-        provider = _resolve_provider(picked_model, providers)
+        #
+        # Pass the explicit provider name through so _resolve_provider
+        # raises ValueError with an actionable message (instead of silently
+        # routing to providers[0]) when an operator picks a provider that
+        # isn't in the registry. See #180.
+        provider = _resolve_provider(
+            picked_model, providers,
+            explicit_provider=explicit_provider_name,
+        )
         auth_env_options = provider["auth_env"]
 
         # Project the per-vendor API key (MINIMAX_API_KEY, GLM_API_KEY,
@@ -522,9 +836,26 @@ class ClaudeCodeAdapter(BaseAdapter):
         # RuntimeConfig dataclass. Read `model` defensively from either shape.
         rc = config.runtime_config
         if isinstance(rc, dict):
-            explicit_model = rc.get("model") or ""
+            yaml_model = rc.get("model") or ""
+            yaml_provider = rc.get("provider") or ""
         else:
-            explicit_model = getattr(rc, "model", None) or ""
+            yaml_model = getattr(rc, "model", None) or ""
+            yaml_provider = getattr(rc, "provider", None) or ""
+
+        # Reconcile against env vars (persona convention: MODEL=<id>,
+        # MODEL_PROVIDER=<slug>) using the same helper that ``setup`` uses,
+        # so the executor and the boot banner agree on the picked model.
+        # Without this, a workspace whose env says ``MODEL=MiniMax-M2.7``
+        # but whose runtime wheel pre-dates the persona-env fix would set
+        # runtime_config.model="minimax" (the slug, mistakenly read by the
+        # legacy ``MODEL_PROVIDER``-as-model-id path); this helper restores
+        # the correct model id before it reaches the SDK.
+        providers = _load_providers(config.config_path)
+        explicit_model, _ = _resolve_model_and_provider_from_env(
+            yaml_model=yaml_model,
+            yaml_provider=yaml_provider,
+            providers=providers,
+        )
         explicit_model = _strip_provider_prefix(explicit_model)
 
         # Pre-validation: detect the misconfiguration combo that drove the
@@ -555,7 +886,7 @@ class ClaudeCodeAdapter(BaseAdapter):
                     "The default fallback ('sonnet') is an Anthropic-native "
                     "alias; non-Anthropic shims (MiniMax, OpenAI gateways, "
                     "etc.) won't recognize it and the SDK --print probe will "
-                    "hang for 30s before timing out. Fix: set MODEL_PROVIDER "
+                    "hang for 30s before timing out. Fix: set MODEL "
                     "as a workspace secret (canvas: Save+Restart with model "
                     "picked) or set runtime_config.model in /configs/config.yaml."
                 )

tests/conftest.py

@@ -0,0 +1,89 @@
+"""Shared pytest fixtures + import shims for the adapter test suite.
+
+`adapter.py` imports at module load:
+  - molecule_runtime.adapters.base (BaseAdapter, AdapterConfig, RuntimeCapabilities)
+  - molecule_runtime.plugins (lazy in setup(), but stubbed proactively)
+  - a2a.server.agent_execution (AgentExecutor)
+  - claude_sdk_executor (lazy in create_executor(), stubbed proactively)
+
+In production those arrive transitively via molecule-ai-workspace-runtime.
+The CI runner only installs `pytest pytest-asyncio pyyaml`, so the import
+chain would fail with ModuleNotFoundError before any test collects —
+exactly the failure that broke CI on the #180 fix branch (PR #4) and
+caused the merge wall to block on a green local but red Gitea CI.
+
+Putting the stub installer here (collected before any test module is
+imported, per pytest semantics) means every test file can do
+`from adapter import ...` at module top without a per-file boilerplate
+copy. It also forces a single shape for the stubs so two files can't
+silently disagree on whether `BaseAdapter` has
+`install_plugins_via_registry` (see test_adapter_prevalidate's
+async-setup tests, which need the method to exist on the parent class).
+"""
+
+import os
+import sys
+import types
+from dataclasses import dataclass
+from unittest.mock import MagicMock
+
+
+@dataclass
+class _StubRuntimeCapabilities:
+    provides_native_session: bool = False
+
+
+@dataclass
+class _StubAdapterConfig:
+    runtime_config: object = None
+    config_path: str = "/tmp/configs"
+    system_prompt: str = ""
+    heartbeat: object = None
+
+
+class _StubBaseAdapter:
+    async def install_plugins_via_registry(self, *_args, **_kwargs):
+        pass
+
+
+def _install_stubs() -> None:
+    """Install the smallest set of import shims that adapter.py needs."""
+    if "molecule_runtime" not in sys.modules:
+        mr = types.ModuleType("molecule_runtime")
+        mr.adapters = types.ModuleType("molecule_runtime.adapters")
+        mr.adapters.base = types.ModuleType("molecule_runtime.adapters.base")
+        mr.adapters.base.BaseAdapter = _StubBaseAdapter
+        mr.adapters.base.AdapterConfig = _StubAdapterConfig
+        mr.adapters.base.RuntimeCapabilities = _StubRuntimeCapabilities
+        mr.plugins = types.ModuleType("molecule_runtime.plugins")
+        mr.plugins.load_plugins = lambda **_kwargs: []
+        sys.modules["molecule_runtime"] = mr
+        sys.modules["molecule_runtime.adapters"] = mr.adapters
+        sys.modules["molecule_runtime.adapters.base"] = mr.adapters.base
+        sys.modules["molecule_runtime.plugins"] = mr.plugins
+    if "a2a" not in sys.modules:
+        a2a = types.ModuleType("a2a")
+        a2a.server = types.ModuleType("a2a.server")
+        a2a.server.agent_execution = types.ModuleType("a2a.server.agent_execution")
+        a2a.server.agent_execution.AgentExecutor = type("AgentExecutor", (), {})
+        sys.modules["a2a"] = a2a
+        sys.modules["a2a.server"] = a2a.server
+        sys.modules["a2a.server.agent_execution"] = a2a.server.agent_execution
+    if "claude_sdk_executor" not in sys.modules:
+        mod = types.ModuleType("claude_sdk_executor")
+        mod.ClaudeSDKExecutor = MagicMock(name="ClaudeSDKExecutor")
+        sys.modules["claude_sdk_executor"] = mod
+
+
+# Run at conftest import time — pytest collects conftest.py before any
+# test module, so the stubs are in sys.modules before `from adapter
+# import ...` ever executes.
+_install_stubs()
+
+# adapter.py lives in the parent dir of tests/ (template root). pytest's
+# `--import-mode=importlib` + tests/pytest.ini anchoring rootdir at
+# tests/ means the parent isn't on sys.path automatically. Add it here
+# once so every test file can do `from adapter import ...` cleanly.
+_PARENT_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+if _PARENT_DIR not in sys.path:
+    sys.path.insert(0, _PARENT_DIR)

tests/test_adapter_prevalidate.py

@@ -514,8 +514,15 @@ async def test_setup_auth_token_alone_satisfies_third_party_check(
 # ---- _load_providers / _resolve_provider unit tests ----
 
 
-def test_load_providers_returns_builtin_when_yaml_missing(tmp_path):
+def test_load_providers_returns_builtin_when_yaml_missing(tmp_path, monkeypatch):
-    """FileNotFoundError path returns the in-code defaults verbatim."""
+    """FileNotFoundError path returns the in-code defaults verbatim.
+
+    Monkeypatches the canonical + template paths to a non-existent dir
+    so only the workspace config_path is in scope. Without this, the
+    multi-path lookup picks up the repo-root config.yaml that ships
+    with the template (path 2 finds the bundled providers list and
+    returns it instead of falling through to builtins).
+    """
     _install_stubs()
     parent_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
     if parent_dir not in sys.path:
@@ -523,6 +530,10 @@ def test_load_providers_returns_builtin_when_yaml_missing(tmp_path):
     sys.modules.pop("adapter", None)
     import adapter as adapter_module
 
+    nonexistent = str(tmp_path / "_isolate_canonical")
+    monkeypatch.setattr(adapter_module, "_CANONICAL_ADAPTER_DIR", nonexistent)
+    monkeypatch.setattr(adapter_module, "_TEMPLATE_DIR", nonexistent)
+
     result = adapter_module._load_providers(str(tmp_path))
     assert result == adapter_module._BUILTIN_PROVIDERS
 
@@ -576,8 +587,12 @@ async def test_setup_routes_extra_providers(
     assert os.environ.get("ANTHROPIC_BASE_URL") == expected_url
 
 
-def test_load_providers_falls_back_on_malformed_yaml(tmp_path, caplog):
+def test_load_providers_falls_back_on_malformed_yaml(tmp_path, caplog, monkeypatch):
-    """Malformed YAML → log warning + fallback (don't kill boot)."""
+    """Malformed YAML → log warning + fallback (don't kill boot).
+
+    Isolated from the multi-path lookup by pinning canonical + template
+    dirs at a non-existent path; only the workspace config_path is read.
+    """
     _install_stubs()
     parent_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
     if parent_dir not in sys.path:
@@ -585,6 +600,10 @@ def test_load_providers_falls_back_on_malformed_yaml(tmp_path, caplog):
     sys.modules.pop("adapter", None)
     import adapter as adapter_module
 
+    nonexistent = str(tmp_path / "_isolate_canonical")
+    monkeypatch.setattr(adapter_module, "_CANONICAL_ADAPTER_DIR", nonexistent)
+    monkeypatch.setattr(adapter_module, "_TEMPLATE_DIR", nonexistent)
+
     (tmp_path / "config.yaml").write_text("providers: [not valid yaml: {{{")
 
     import logging
@@ -622,7 +641,7 @@ def test_resolve_provider_minimax_prefix_matches_minimax_provider():
     assert result2["name"] == "minimax"
 
 
-def test_load_providers_drops_bad_entry_keeps_rest(tmp_path, caplog):
+def test_load_providers_drops_bad_entry_keeps_rest(tmp_path, caplog, monkeypatch):
     """Per-entry isolation: one malformed entry shouldn't nuke the registry.
 
     Pre-fix: ``_load_providers`` built the registry via a generator inside
@@ -634,6 +653,9 @@ def test_load_providers_drops_bad_entry_keeps_rest(tmp_path, caplog):
 
     Post-fix: per-entry try/except drops the bad entry with a warning,
     rest of the registry survives.
+
+    Isolated from the multi-path lookup so only the test's tmp config.yaml
+    is read.
     """
     _install_stubs()
     parent_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
@@ -642,6 +664,10 @@ def test_load_providers_drops_bad_entry_keeps_rest(tmp_path, caplog):
     sys.modules.pop("adapter", None)
     import adapter as adapter_module
 
+    nonexistent = str(tmp_path / "_isolate_canonical")
+    monkeypatch.setattr(adapter_module, "_CANONICAL_ADAPTER_DIR", nonexistent)
+    monkeypatch.setattr(adapter_module, "_TEMPLATE_DIR", nonexistent)
+
     yaml_with_typo = textwrap.dedent("""
         providers:
           - name: good-zai
@@ -690,7 +716,7 @@ def test_load_providers_drops_bad_entry_keeps_rest(tmp_path, caplog):
     )
 
 
-def test_load_providers_string_as_prefix_does_not_split_into_chars(tmp_path, caplog):
+def test_load_providers_string_as_prefix_does_not_split_into_chars(tmp_path, caplog, monkeypatch):
     """A YAML field declared as list-of-strings but written as a bare
     string (operator forgot brackets) used to silently iterate over
     characters → ``('m','i','m','o','-')``. Post-fix: non-list value
@@ -705,6 +731,10 @@ def test_load_providers_string_as_prefix_does_not_split_into_chars(tmp_path, cap
     sys.modules.pop("adapter", None)
     import adapter as adapter_module
 
+    nonexistent = str(tmp_path / "_isolate_canonical")
+    monkeypatch.setattr(adapter_module, "_CANONICAL_ADAPTER_DIR", nonexistent)
+    monkeypatch.setattr(adapter_module, "_TEMPLATE_DIR", nonexistent)
+
     yaml_str_prefix = textwrap.dedent("""
         providers:
           - name: typo-prefix
@@ -723,7 +753,7 @@ def test_load_providers_string_as_prefix_does_not_split_into_chars(tmp_path, cap
     )
 
 
-def test_load_providers_drops_entry_without_name(tmp_path, caplog):
+def test_load_providers_drops_entry_without_name(tmp_path, caplog, monkeypatch):
     """An entry without ``name`` is operator error — no silent fallback
     to ``<unnamed>``. Drop the entry with a warning so the boot log
     surfaces the typo.
@@ -735,6 +765,10 @@ def test_load_providers_drops_entry_without_name(tmp_path, caplog):
     sys.modules.pop("adapter", None)
     import adapter as adapter_module
 
+    nonexistent = str(tmp_path / "_isolate_canonical")
+    monkeypatch.setattr(adapter_module, "_CANONICAL_ADAPTER_DIR", nonexistent)
+    monkeypatch.setattr(adapter_module, "_TEMPLATE_DIR", nonexistent)
+
     yaml_no_name = textwrap.dedent("""
         providers:
           - name: good

tests/test_env_model_provider_dispatch.py

@@ -0,0 +1,287 @@
+"""Tests for ``_resolve_model_and_provider_from_env`` — the env-vs-YAML
+reconciliation that fixes the 2026-05-08 dev-tree wedge incident.
+
+Symptom: 22/27 non-lead workspaces (minimax tier) wedged on
+``Control request timeout: initialize`` because the runtime wheel's
+``workspace/config.py`` interpreted ``MODEL_PROVIDER=minimax`` as the
+*model id* instead of the provider slug. ``model="minimax"`` failed to
+match the ``minimax-`` registry prefix, fell through to providers[0]
+(anthropic-oauth), demanded ``CLAUDE_CODE_OAUTH_TOKEN`` (unset on
+non-leads), and the claude CLI hung at SDK init.
+
+The persona env files (``~/.molecule-ai/personas/<name>/env``) declare
+the new convention:
+  * ``MODEL`` — model id (e.g. ``MiniMax-M2.7-highspeed``)
+  * ``MODEL_PROVIDER`` — provider slug (e.g. ``minimax``)
+
+These tests cover the matrix of (env shape) × (YAML shape) so a future
+contributor can't silently regress the wedge fix.
+"""
+
+import pytest
+
+from adapter import (
+    _BUILTIN_PROVIDERS,
+    _resolve_model_and_provider_from_env,
+)
+
+
+# A registry that contains both anthropic-oauth (providers[0]) and
+# minimax/zai (third-party slugs) — matches the shipped config.yaml.
+_REGISTRY = _BUILTIN_PROVIDERS + (
+    {
+        "name": "minimax",
+        "auth_mode": "third_party_anthropic_compat",
+        "model_prefixes": ("minimax-",),
+        "model_aliases": (),
+        "base_url": "https://api.minimax.io/anthropic",
+        "auth_env": ("MINIMAX_API_KEY",),
+    },
+    {
+        "name": "zai",
+        "auth_mode": "third_party_anthropic_compat",
+        "model_prefixes": ("glm-",),
+        "model_aliases": (),
+        "base_url": "https://api.z.ai/api/anthropic",
+        "auth_env": ("GLM_API_KEY",),
+    },
+)
+
+
+def _clear_env(monkeypatch):
+    monkeypatch.delenv("MODEL", raising=False)
+    monkeypatch.delenv("MODEL_PROVIDER", raising=False)
+
+
+# ------------------------------------------------------------------
+# Persona env convention: MODEL=<id>, MODEL_PROVIDER=<slug>
+# ------------------------------------------------------------------
+
+def test_persona_env_minimax_resolves_correctly(monkeypatch):
+    """The 2026-05-08 wedge regression test: persona env shape must
+    yield model=MiniMax-M2.7-highspeed (not "minimax") and explicit
+    provider=minimax."""
+    _clear_env(monkeypatch)
+    monkeypatch.setenv("MODEL", "MiniMax-M2.7-highspeed")
+    monkeypatch.setenv("MODEL_PROVIDER", "minimax")
+    model, provider = _resolve_model_and_provider_from_env(
+        yaml_model="", yaml_provider="", providers=_REGISTRY,
+    )
+    assert model == "MiniMax-M2.7-highspeed"
+    assert provider == "minimax"
+
+
+def test_persona_env_lead_claude_code_resolves_correctly(monkeypatch):
+    """Lead persona env (MODEL=opus, MODEL_PROVIDER=claude-code) —
+    ``claude-code`` is the persona-friendly alias for the canonical
+    ``anthropic-oauth`` registry name. Must resolve via the alias map
+    so the lead boots through the OAuth subscription path even when
+    MODEL is a non-Anthropic model id (e.g. an operator who picked
+    MiniMax in canvas but whose persona env still pins claude-code)."""
+    _clear_env(monkeypatch)
+    monkeypatch.setenv("MODEL", "opus")
+    monkeypatch.setenv("MODEL_PROVIDER", "claude-code")
+    model, provider = _resolve_model_and_provider_from_env(
+        yaml_model="", yaml_provider="", providers=_REGISTRY,
+    )
+    assert model == "opus"
+    # claude-code → anthropic-oauth via the alias map
+    assert provider == "anthropic-oauth"
+
+
+def test_persona_env_lead_with_minimax_model_routes_via_oauth(monkeypatch):
+    """Lead workspace whose persona pins MODEL_PROVIDER=claude-code but
+    whose YAML/canvas selection happens to be a MiniMax model still
+    routes via OAuth — the persona's provider pin wins over the
+    model-prefix matcher. Without the alias map, the fall-through
+    mis-routed leads to MiniMax even when their CLAUDE_CODE_OAUTH_TOKEN
+    was set."""
+    _clear_env(monkeypatch)
+    monkeypatch.setenv("MODEL", "MiniMax-M2.7")
+    monkeypatch.setenv("MODEL_PROVIDER", "claude-code")
+    model, provider = _resolve_model_and_provider_from_env(
+        yaml_model="", yaml_provider="", providers=_REGISTRY,
+    )
+    assert model == "MiniMax-M2.7"
+    assert provider == "anthropic-oauth"
+
+
+def test_anthropic_alias_resolves_to_anthropic_api(monkeypatch):
+    """``MODEL_PROVIDER=anthropic`` alias → ``anthropic-api`` (direct
+    Anthropic API key path)."""
+    _clear_env(monkeypatch)
+    monkeypatch.setenv("MODEL", "claude-opus-4-7")
+    monkeypatch.setenv("MODEL_PROVIDER", "anthropic")
+    model, provider = _resolve_model_and_provider_from_env(
+        yaml_model="", yaml_provider="", providers=_REGISTRY,
+    )
+    assert model == "claude-opus-4-7"
+    assert provider == "anthropic-api"
+
+
+def test_persona_env_glm_resolves_correctly(monkeypatch):
+    _clear_env(monkeypatch)
+    monkeypatch.setenv("MODEL", "GLM-4.6")
+    monkeypatch.setenv("MODEL_PROVIDER", "zai")
+    model, provider = _resolve_model_and_provider_from_env(
+        yaml_model="", yaml_provider="", providers=_REGISTRY,
+    )
+    assert model == "GLM-4.6"
+    assert provider == "zai"
+
+
+def test_env_provider_slug_case_insensitive(monkeypatch):
+    """Operator typos like ``MiniMax`` (mixed case) still resolve."""
+    _clear_env(monkeypatch)
+    monkeypatch.setenv("MODEL", "MiniMax-M2.7-highspeed")
+    monkeypatch.setenv("MODEL_PROVIDER", "MiniMax")  # mixed case
+    _, provider = _resolve_model_and_provider_from_env(
+        yaml_model="", yaml_provider="", providers=_REGISTRY,
+    )
+    assert provider == "MiniMax"  # caller compares case-insensitively
+
+
+# ------------------------------------------------------------------
+# Legacy convention: MODEL_PROVIDER=<model-id>, MODEL unset
+# ------------------------------------------------------------------
+
+def test_legacy_model_provider_as_model_id_still_works(monkeypatch):
+    """Pre-2026-05-08 canvas Save+Restart shape: MODEL_PROVIDER carried
+    the model id directly (e.g. ``MODEL_PROVIDER=MiniMax-M2.7``) and
+    no MODEL env. Must keep working so existing canvas users don't
+    break overnight."""
+    _clear_env(monkeypatch)
+    monkeypatch.setenv("MODEL_PROVIDER", "MiniMax-M2.7-highspeed")
+    model, provider = _resolve_model_and_provider_from_env(
+        yaml_model="", yaml_provider="", providers=_REGISTRY,
+    )
+    # MiniMax-M2.7-highspeed is not a registered provider name, so
+    # it's treated as a legacy model-id-in-MODEL_PROVIDER value.
+    assert model == "MiniMax-M2.7-highspeed"
+    assert provider is None
+
+
+# ------------------------------------------------------------------
+# Env wins over YAML
+# ------------------------------------------------------------------
+
+def test_env_model_wins_over_yaml_model(monkeypatch):
+    """When both env MODEL and YAML model are set, env wins."""
+    _clear_env(monkeypatch)
+    monkeypatch.setenv("MODEL", "GLM-4.6")
+    model, _ = _resolve_model_and_provider_from_env(
+        yaml_model="MiniMax-M2.7", yaml_provider="", providers=_REGISTRY,
+    )
+    assert model == "GLM-4.6"
+
+
+def test_env_provider_wins_over_yaml_provider(monkeypatch):
+    """Env MODEL_PROVIDER (when a registered slug) wins over YAML provider."""
+    _clear_env(monkeypatch)
+    monkeypatch.setenv("MODEL", "GLM-4.6")
+    monkeypatch.setenv("MODEL_PROVIDER", "zai")
+    _, provider = _resolve_model_and_provider_from_env(
+        yaml_model="", yaml_provider="minimax", providers=_REGISTRY,
+    )
+    assert provider == "zai"
+
+
+# ------------------------------------------------------------------
+# YAML fallback (no env)
+# ------------------------------------------------------------------
+
+def test_no_env_falls_back_to_yaml(monkeypatch):
+    """Workspace whose env doesn't set MODEL/MODEL_PROVIDER falls back
+    to the YAML config — preserves existing operator workflows."""
+    _clear_env(monkeypatch)
+    model, provider = _resolve_model_and_provider_from_env(
+        yaml_model="claude-sonnet-4-6",
+        yaml_provider="anthropic-api",
+        providers=_REGISTRY,
+    )
+    assert model == "claude-sonnet-4-6"
+    assert provider == "anthropic-api"
+
+
+def test_no_env_no_yaml_returns_empty(monkeypatch):
+    """Pure default path — caller (setup) substitutes ``sonnet``."""
+    _clear_env(monkeypatch)
+    model, provider = _resolve_model_and_provider_from_env(
+        yaml_model="", yaml_provider="", providers=_REGISTRY,
+    )
+    assert model == ""
+    assert provider is None
+
+
+def test_yaml_provider_anthropic_is_aliased_to_anthropic_api(monkeypatch):
+    """Regression for 2026-05-09 staging-cplead-2 incident: every
+    workspace booted ``configuration_status=not_configured`` because the
+    molecule-runtime wheel auto-derives ``runtime_config.provider =
+    "anthropic"`` from the default model slug ``anthropic:claude-opus-4-7``.
+    The adapter received ``yaml_provider="anthropic"`` from the wheel and
+    rejected it with ``ValueError: provider='anthropic' but it is not in
+    the providers registry`` — but ``anthropic`` is already in
+    ``_PROVIDER_SLUG_ALIASES`` for the env-var path. Mirror the alias map
+    on the YAML path so the wheel default produces a registered provider
+    name."""
+    _clear_env(monkeypatch)
+    _, provider = _resolve_model_and_provider_from_env(
+        yaml_model="", yaml_provider="anthropic", providers=_REGISTRY,
+    )
+    assert provider == "anthropic-api", (
+        f"yaml_provider='anthropic' must resolve through the alias map to "
+        f"'anthropic-api'; got {provider!r}. Without this aliasing the "
+        f"wheel-default workspace boot wedges at adapter.setup()."
+    )
+
+
+def test_yaml_provider_claude_code_is_aliased_to_anthropic_oauth(monkeypatch):
+    """Symmetric coverage: persona-friendly ``claude-code`` slug from the
+    YAML ``provider:`` field must alias to ``anthropic-oauth``, the same
+    way the env-var path resolves it. Lead workspaces that pin the OAuth
+    path in YAML (instead of via env) must not wedge."""
+    _clear_env(monkeypatch)
+    _, provider = _resolve_model_and_provider_from_env(
+        yaml_model="", yaml_provider="claude-code", providers=_REGISTRY,
+    )
+    assert provider == "anthropic-oauth"
+
+
+def test_yaml_provider_unknown_passes_through_for_actionable_error(monkeypatch):
+    """An unaliased, unknown YAML provider (e.g. ``yaml_provider="mystery"``)
+    must NOT be silently swapped to providers[0] — it must reach
+    ``_resolve_provider`` so the adapter raises the actionable
+    ``Known providers: ...`` error message. The alias map is a
+    convenience for the two persona-convention slugs only; everything
+    else must keep its original semantics."""
+    _clear_env(monkeypatch)
+    _, provider = _resolve_model_and_provider_from_env(
+        yaml_model="", yaml_provider="mystery", providers=_REGISTRY,
+    )
+    assert provider == "mystery"
+
+
+# ------------------------------------------------------------------
+# Whitespace / empty-value defensive cases
+# ------------------------------------------------------------------
+
+def test_whitespace_only_env_treated_as_unset(monkeypatch):
+    _clear_env(monkeypatch)
+    monkeypatch.setenv("MODEL", "   ")
+    monkeypatch.setenv("MODEL_PROVIDER", "  ")
+    model, provider = _resolve_model_and_provider_from_env(
+        yaml_model="opus", yaml_provider="", providers=_REGISTRY,
+    )
+    assert model == "opus"
+    assert provider is None
+
+
+def test_empty_env_value_treated_as_unset(monkeypatch):
+    _clear_env(monkeypatch)
+    monkeypatch.setenv("MODEL", "")
+    monkeypatch.setenv("MODEL_PROVIDER", "")
+    model, provider = _resolve_model_and_provider_from_env(
+        yaml_model="sonnet", yaml_provider="", providers=_REGISTRY,
+    )
+    assert model == "sonnet"
+    assert provider is None

tests/test_provider_resolution.py

@@ -0,0 +1,146 @@
+"""Tests for the provider-resolution path that was silent-failing on #180.
+
+Regression coverage: when an operator picks a provider in the canvas Config
+tab that isn't in the registry, the adapter must raise ValueError with an
+actionable message — NOT silently fall through to providers[0]
+(anthropic-oauth) and then have the Claude SDK hit the user's OAuth quota
+under a different name.
+
+These tests mirror the production failure mode reported by Hongming
+2026-05-07 17:35: workspace config.yaml had `provider: minimax` set, the
+adapter ignored it entirely, the SDK kept calling the Anthropic API with
+CLAUDE_CODE_OAUTH_TOKEN, hit the OAuth quota, and the canvas surfaced
+"Agent error (Exception)" with no clue why.
+
+Import-shim setup (sys.path + molecule_runtime / a2a / claude_sdk_executor
+stubs) lives in tests/conftest.py — shared with test_adapter_prevalidate
+so the two stub installers can't disagree on shape (e.g. BaseAdapter
+having install_plugins_via_registry).
+"""
+
+import pytest
+
+from adapter import (
+    _BUILTIN_PROVIDERS,
+    _resolve_provider,
+)
+
+
+def test_resolve_with_no_explicit_provider_falls_back_to_model_match():
+    """No explicit provider → model-based prefix/alias matching, default to providers[0]."""
+    p = _resolve_provider("claude-opus-4-7", _BUILTIN_PROVIDERS)
+    assert p["name"] == "anthropic-api"  # matches model_prefixes=("claude-",)
+
+
+def test_resolve_with_no_explicit_provider_falls_back_to_default():
+    """Unknown model + no explicit provider → providers[0] (anthropic-oauth)."""
+    p = _resolve_provider("unknown-model", _BUILTIN_PROVIDERS)
+    assert p["name"] == "anthropic-oauth"
+
+
+def test_resolve_with_explicit_provider_in_registry_returns_match():
+    """Explicit name lookup wins over model-based resolution."""
+    # Even though "claude-opus-4-7" would normally resolve to anthropic-api
+    # via prefix matching, the explicit provider name wins.
+    p = _resolve_provider(
+        "claude-opus-4-7", _BUILTIN_PROVIDERS,
+        explicit_provider="anthropic-oauth",
+    )
+    assert p["name"] == "anthropic-oauth"
+
+
+def test_resolve_with_explicit_provider_case_insensitive():
+    """Provider name match is case-insensitive (operators write 'Anthropic-OAuth' etc)."""
+    p = _resolve_provider(
+        "sonnet", _BUILTIN_PROVIDERS,
+        explicit_provider="ANTHROPIC-OAUTH",
+    )
+    assert p["name"] == "anthropic-oauth"
+
+
+def test_resolve_with_explicit_provider_not_in_registry_raises():
+    """The #180 regression test: explicit non-registry provider must raise, not fall through."""
+    with pytest.raises(ValueError) as exc_info:
+        _resolve_provider(
+            "MiniMax-M2.7-highspeed", _BUILTIN_PROVIDERS,
+            explicit_provider="minimax",
+        )
+    msg = str(exc_info.value)
+    # Must name the bad provider so operator knows what they typed
+    assert "minimax" in msg
+    # Must list known providers so operator knows what's available
+    assert "anthropic-oauth" in msg
+    assert "anthropic-api" in msg
+    # Must give actionable next steps — NOT just "not found"
+    assert "providers:" in msg or "Add" in msg
+    assert "Switch" in msg or "runtime" in msg
+
+
+def test_resolve_with_explicit_provider_does_not_silent_fallback():
+    """Specifically: must not return providers[0] when explicit_provider is bogus.
+
+    This is the exact silent-fallback path that caused the user-visible
+    bug: operator picks 'minimax' → adapter returns anthropic-oauth →
+    SDK uses CLAUDE_CODE_OAUTH_TOKEN → hits quota.
+    """
+    with pytest.raises(ValueError):
+        result = _resolve_provider(
+            "anything", _BUILTIN_PROVIDERS,
+            explicit_provider="minimax",
+        )
+        # If the implementation regresses to silent fallback, this would
+        # have returned providers[0] (anthropic-oauth) instead of raising.
+        # Defense-in-depth: guard against accidental "return" inside the
+        # error path.
+        assert result["name"] not in {"anthropic-oauth", "anthropic-api"}, (
+            "REGRESSION: silent fallback to default provider when explicit "
+            "provider name is not in registry — this is the #180 bug."
+        )
+
+
+def test_resolve_with_explicit_provider_in_custom_registry():
+    """When operator adds a third-party provider to the registry, explicit lookup finds it."""
+    custom_registry = _BUILTIN_PROVIDERS + (
+        {
+            "name": "minimax",
+            "auth_mode": "third_party_anthropic_compat",
+            "model_prefixes": ("minimax-",),
+            "model_aliases": (),
+            "base_url": "https://api.minimaxi.com/anthropic-compat",
+            "auth_env": ("MINIMAX_API_KEY",),
+        },
+    )
+    p = _resolve_provider(
+        "MiniMax-M2.7-highspeed", custom_registry,
+        explicit_provider="minimax",
+    )
+    assert p["name"] == "minimax"
+    assert p["base_url"] == "https://api.minimaxi.com/anthropic-compat"
+    assert "MINIMAX_API_KEY" in p["auth_env"]
+
+
+def test_resolve_empty_providers_raises():
+    """Pre-condition: providers must be non-empty (existing behavior preserved)."""
+    with pytest.raises(ValueError, match="empty providers tuple"):
+        _resolve_provider("anything", ())
+
+
+def test_resolve_explicit_empty_string_treated_as_no_explicit():
+    """`provider: ''` (empty string) → fall back to model-based resolution, not raise."""
+    # This shape can happen when the canvas writes an empty provider field.
+    # Treating it as "no explicit pick" is more forgiving than raising,
+    # since the user clearly didn't intend to break their workspace.
+    p = _resolve_provider(
+        "claude-opus-4-7", _BUILTIN_PROVIDERS,
+        explicit_provider="",
+    )
+    assert p["name"] == "anthropic-api"  # fell through to model-based
+
+
+def test_resolve_explicit_none_treated_as_no_explicit():
+    """`explicit_provider=None` (default) → fall back to model-based resolution."""
+    p = _resolve_provider(
+        "claude-opus-4-7", _BUILTIN_PROVIDERS,
+        explicit_provider=None,
+    )
+    assert p["name"] == "anthropic-api"