feat(image_gen): multi-model FAL support with picker in hermes tools

hermes_cli/tools_config.py

@@ -249,14 +249,16 @@ def _get_plugin_toolset_keys() -> set:
                 "requires_nous_auth": True,
                 "managed_nous_feature": "image_gen",
                 "override_env_vars": ["FAL_KEY"],
+                "imagegen_backend": "fal",
             },
             {
                 "name": "FAL.ai",
                 "badge": "paid",
-                "tag": "FLUX 2 Pro with auto-upscaling",
+                "tag": "Pick from flux-2-klein, flux-2-pro, gpt-image, nano-banana, etc.",
                 "env_vars": [
                     {"key": "FAL_KEY", "prompt": "FAL API key", "url": "https://fal.ai/dashboard/keys"},
                 ],
+                "imagegen_backend": "fal",
             },
         ],
     },
@@ -941,6 +943,106 @@ def _detect_active_provider_index(providers: list, config: dict) -> int:
     return 0
 
 
+# ─── Image Generation Model Pickers ───────────────────────────────────────────
+#
+# IMAGEGEN_BACKENDS is a per-backend catalog. Each entry exposes:
+#   - config_key:        top-level config.yaml key for this backend's settings
+#   - model_catalog_fn:  returns an OrderedDict-like {model_id: metadata}
+#   - default_model:     fallback when nothing is configured
+#
+# This prepares for future imagegen backends (Replicate, Stability, etc.):
+# each new backend registers its own entry; the FAL provider entry in
+# TOOL_CATEGORIES tags itself with `imagegen_backend: "fal"` to select the
+# right catalog at picker time.
+
+
+def _fal_model_catalog():
+    """Lazy-load the FAL model catalog from the tool module."""
+    from tools.image_generation_tool import FAL_MODELS, DEFAULT_MODEL
+    return FAL_MODELS, DEFAULT_MODEL
+
+
+IMAGEGEN_BACKENDS = {
+    "fal": {
+        "display": "FAL.ai",
+        "config_key": "image_gen",
+        "catalog_fn": _fal_model_catalog,
+    },
+}
+
+
+def _format_imagegen_model_row(model_id: str, meta: dict, widths: dict) -> str:
+    """Format a single picker row with column-aligned speed / strengths / price."""
+    return (
+        f"{model_id:<{widths['model']}}  "
+        f"{meta.get('speed', ''):<{widths['speed']}}  "
+        f"{meta.get('strengths', ''):<{widths['strengths']}}  "
+        f"{meta.get('price', '')}"
+    )
+
+
+def _configure_imagegen_model(backend_name: str, config: dict) -> None:
+    """Prompt the user to pick a model for the given imagegen backend.
+
+    Writes selection to ``config[backend_config_key]["model"]``. Safe to
+    call even when stdin is not a TTY — curses_radiolist falls back to
+    keeping the current selection.
+    """
+    backend = IMAGEGEN_BACKENDS.get(backend_name)
+    if not backend:
+        return
+
+    catalog, default_model = backend["catalog_fn"]()
+    if not catalog:
+        return
+
+    cfg_key = backend["config_key"]
+    cur_cfg = config.setdefault(cfg_key, {})
+    if not isinstance(cur_cfg, dict):
+        cur_cfg = {}
+        config[cfg_key] = cur_cfg
+    current_model = cur_cfg.get("model") or default_model
+    if current_model not in catalog:
+        current_model = default_model
+
+    model_ids = list(catalog.keys())
+    # Put current model at the top so the cursor lands on it by default.
+    ordered = [current_model] + [m for m in model_ids if m != current_model]
+
+    # Column widths
+    widths = {
+        "model": max(len(m) for m in model_ids),
+        "speed": max((len(catalog[m].get("speed", "")) for m in model_ids), default=6),
+        "strengths": max((len(catalog[m].get("strengths", "")) for m in model_ids), default=0),
+    }
+
+    print()
+    header = (
+        f"  {'Model':<{widths['model']}}  "
+        f"{'Speed':<{widths['speed']}}  "
+        f"{'Strengths':<{widths['strengths']}}  "
+        f"Price"
+    )
+    print(color(header, Colors.CYAN))
+
+    rows = []
+    for mid in ordered:
+        row = _format_imagegen_model_row(mid, catalog[mid], widths)
+        if mid == current_model:
+            row += "  ← currently in use"
+        rows.append(row)
+
+    idx = _prompt_choice(
+        f"  Choose {backend['display']} model:",
+        rows,
+        default=0,
+    )
+
+    chosen = ordered[idx]
+    cur_cfg["model"] = chosen
+    _print_success(f"  Model set to: {chosen}")
+
+
 def _configure_provider(provider: dict, config: dict):
     """Configure a single provider - prompt for API keys and set config."""
     env_vars = provider.get("env_vars", [])
@@ -997,6 +1099,10 @@ def _configure_provider(provider: dict, config: dict):
         _print_success(f"  {provider['name']} - no configuration needed!")
         if managed_feature:
             _print_info("  Requests for this tool will be billed to your Nous subscription.")
+        # Imagegen backends prompt for model selection after backend pick.
+        backend = provider.get("imagegen_backend")
+        if backend:
+            _configure_imagegen_model(backend, config)
         return
 
     # Prompt for each required env var
@@ -1031,6 +1137,10 @@ def _configure_provider(provider: dict, config: dict):
 
     if all_configured:
         _print_success(f"  {provider['name']} configured!")
+        # Imagegen backends prompt for model selection after env vars are in.
+        backend = provider.get("imagegen_backend")
+        if backend:
+            _configure_imagegen_model(backend, config)
 
 
 def _configure_simple_requirements(ts_key: str):
@@ -1202,6 +1312,10 @@ def _reconfigure_provider(provider: dict, config: dict):
         _print_success(f"  {provider['name']} - no configuration needed!")
         if managed_feature:
             _print_info("  Requests for this tool will be billed to your Nous subscription.")
+        # Imagegen backends prompt for model selection on reconfig too.
+        backend = provider.get("imagegen_backend")
+        if backend:
+            _configure_imagegen_model(backend, config)
         return
 
     for var in env_vars:
@@ -1219,6 +1333,11 @@ def _reconfigure_provider(provider: dict, config: dict):
         else:
             _print_info("    Kept current")
 
+    # Imagegen backends prompt for model selection on reconfig too.
+    backend = provider.get("imagegen_backend")
+    if backend:
+        _configure_imagegen_model(backend, config)
+
 
 def _reconfigure_simple_requirements(ts_key: str):
     """Reconfigure simple env var requirements."""

tests/hermes_cli/test_tools_config.py

@@ -466,3 +466,90 @@ def test_numeric_mcp_server_name_does_not_crash_sorted():
 
     # sorted() must not raise TypeError
     sorted(enabled)
+
+
+# ─── Imagegen Backend Picker Wiring ────────────────────────────────────────
+
+class TestImagegenBackendRegistry:
+    """IMAGEGEN_BACKENDS tags drive the model picker flow in tools_config."""
+
+    def test_fal_backend_registered(self):
+        from hermes_cli.tools_config import IMAGEGEN_BACKENDS
+        assert "fal" in IMAGEGEN_BACKENDS
+
+    def test_fal_catalog_loads_lazily(self):
+        """catalog_fn should defer import to avoid import cycles."""
+        from hermes_cli.tools_config import IMAGEGEN_BACKENDS
+        catalog, default = IMAGEGEN_BACKENDS["fal"]["catalog_fn"]()
+        assert default == "fal-ai/flux-2/klein/9b"
+        assert "fal-ai/flux-2/klein/9b" in catalog
+        assert "fal-ai/flux-2-pro" in catalog
+
+    def test_image_gen_providers_tagged_with_fal_backend(self):
+        """Both Nous Subscription and FAL.ai providers must carry the
+        imagegen_backend tag so _configure_provider fires the picker."""
+        from hermes_cli.tools_config import TOOL_CATEGORIES
+        providers = TOOL_CATEGORIES["image_gen"]["providers"]
+        for p in providers:
+            assert p.get("imagegen_backend") == "fal", (
+                f"{p['name']} missing imagegen_backend tag"
+            )
+
+
+class TestImagegenModelPicker:
+    """_configure_imagegen_model writes selection to config and respects
+    curses fallback semantics (returns default when stdin isn't a TTY)."""
+
+    def test_picker_writes_chosen_model_to_config(self):
+        from hermes_cli.tools_config import _configure_imagegen_model
+        config = {}
+        # Force _prompt_choice to pick index 1 (second-in-ordered-list).
+        with patch("hermes_cli.tools_config._prompt_choice", return_value=1):
+            _configure_imagegen_model("fal", config)
+        # ordered[0] == current (default klein), ordered[1] == first non-default
+        assert config["image_gen"]["model"] != "fal-ai/flux-2/klein/9b"
+        assert config["image_gen"]["model"].startswith("fal-ai/")
+
+    def test_picker_with_gpt_image_does_not_prompt_quality(self):
+        """GPT-Image quality is pinned to medium in the tool's defaults —
+        no follow-up prompt, no config write for quality_setting."""
+        from hermes_cli.tools_config import (
+            _configure_imagegen_model,
+            IMAGEGEN_BACKENDS,
+        )
+        catalog, default_model = IMAGEGEN_BACKENDS["fal"]["catalog_fn"]()
+        model_ids = list(catalog.keys())
+        ordered = [default_model] + [m for m in model_ids if m != default_model]
+        gpt_idx = ordered.index("fal-ai/gpt-image-1.5")
+
+        # Only ONE picker call is expected (for model) — not two (model + quality).
+        call_count = {"n": 0}
+        def fake_prompt(*a, **kw):
+            call_count["n"] += 1
+            return gpt_idx
+
+        config = {}
+        with patch("hermes_cli.tools_config._prompt_choice", side_effect=fake_prompt):
+            _configure_imagegen_model("fal", config)
+
+        assert call_count["n"] == 1, (
+            f"Expected 1 picker call (model only), got {call_count['n']}"
+        )
+        assert config["image_gen"]["model"] == "fal-ai/gpt-image-1.5"
+        assert "quality_setting" not in config["image_gen"]
+
+    def test_picker_no_op_for_unknown_backend(self):
+        from hermes_cli.tools_config import _configure_imagegen_model
+        config = {}
+        _configure_imagegen_model("nonexistent-backend", config)
+        assert config == {}  # untouched
+
+    def test_picker_repairs_corrupt_config_section(self):
+        """When image_gen is a non-dict (user-edit YAML), the picker should
+        replace it with a fresh dict rather than crash."""
+        from hermes_cli.tools_config import _configure_imagegen_model
+        config = {"image_gen": "some-garbage-string"}
+        with patch("hermes_cli.tools_config._prompt_choice", return_value=0):
+            _configure_imagegen_model("fal", config)
+        assert isinstance(config["image_gen"], dict)
+        assert config["image_gen"]["model"] == "fal-ai/flux-2/klein/9b"