feat: add MiniMax as alternative LLM provider

Add multi-provider LLM factory with auto-detection from API keys.
MiniMax M2.7/M2.7-highspeed models supported via OpenAI-compatible API
with temperature clamping and configurable base URL.

- New llm_provider.py module with create_llm() factory
- Provider auto-detection: MINIMAX_API_KEY → minimax, else openai
- LLM_PROVIDER, LLM_BASE_URL, LLM_TEMPERATURE env vars
- 28 unit tests + 3 integration tests
- Updated .env.example and README with MiniMax docs

Author: octopus

.env.example

@@ -1,9 +1,19 @@
 OPENAI_API_KEY=
 
+# LLM provider — auto-detected from API keys if unset
+# Options: openai, minimax
+# LLM_PROVIDER=openai
+
 # LLM model — strong models are required for reliable UI generation
-# Recommended: gpt-5.4, gpt-5.4-pro, claude-opus-4-6, gemini-3.1-pro
+# Recommended: gpt-5.4, gpt-5.4-pro, claude-opus-4-6, gemini-3.1-pro, MiniMax-M2.7
 LLM_MODEL=gpt-5.4-2026-03-05
 
+# Custom base URL for OpenAI-compatible providers (overrides provider preset)
+# LLM_BASE_URL=
+
+# MiniMax (https://www.minimaxi.com) — set key to auto-select MiniMax provider
+# MINIMAX_API_KEY=
+
 # Rate limiting (per IP) — disabled by default
 RATE_LIMIT_ENABLED=false
 RATE_LIMIT_WINDOW_MS=60000

README.md

@@ -30,8 +30,11 @@ make dev      # Start all services
 > | `gpt-5.4` / `gpt-5.4-pro` | OpenAI |
 > | `claude-opus-4-6` | Anthropic |
 > | `gemini-3.1-pro` | Google |
+> | `MiniMax-M2.7` / `MiniMax-M2.7-highspeed` | [MiniMax](https://www.minimaxi.com) |
 >
 > Smaller or weaker models will produce broken layouts, missing interactivity, or incomplete visualizations.
+>
+> **Using MiniMax:** Set `MINIMAX_API_KEY` in your `.env` — the provider is auto-detected. Defaults to `MiniMax-M2.7` (1M context window). See [MiniMax docs](https://www.minimaxi.com/document/introduction) for API keys.
 
 - **App**: http://localhost:3000
 - **Agent**: http://localhost:8123

apps/agent/main.py

@@ -3,12 +3,10 @@
 It defines the workflow graph, state, tools, nodes and edges.
 """
 
-import os
-
 from copilotkit import CopilotKitMiddleware
 from langchain.agents import create_agent
-from langchain_openai import ChatOpenAI
 
+from src.llm_provider import create_llm
 from src.query import query_data
 from src.todos import AgentState, todo_tools
 from src.form import generate_form
@@ -19,7 +17,7 @@
 _skills_text = load_all_skills()
 
 agent = create_agent(
-    model=ChatOpenAI(model=os.environ.get("LLM_MODEL", "gpt-5.4-2026-03-05")),
+    model=create_llm(),
     tools=[query_data, *todo_tools, generate_form, *template_tools],
     middleware=[CopilotKitMiddleware()],
     state_schema=AgentState,

apps/agent/src/llm_provider.py

@@ -0,0 +1,89 @@
+"""
+LLM provider factory for multi-provider support.
+
+Supports OpenAI (default), MiniMax, and any OpenAI-compatible provider
+via the LLM_BASE_URL environment variable.
+
+Provider auto-detection priority:
+  1. Explicit LLM_PROVIDER env var
+  2. MINIMAX_API_KEY present → minimax
+  3. OPENAI_API_KEY present → openai (default)
+
+MiniMax models use the OpenAI-compatible API at https://api.minimax.io/v1
+with temperature clamped to (0.0, 1.0].
+"""
+
+import os
+from langchain_openai import ChatOpenAI
+
+
+# Provider presets: base_url and api_key env var name
+PROVIDER_PRESETS = {
+    "openai": {
+        "base_url": None,  # uses default
+        "api_key_env": "OPENAI_API_KEY",
+    },
+    "minimax": {
+        "base_url": "https://api.minimax.io/v1",
+        "api_key_env": "MINIMAX_API_KEY",
+        "default_model": "MiniMax-M2.7",
+    },
+}
+
+# Models that require temperature clamping to (0.0, 1.0]
+_CLAMP_TEMPERATURE_PROVIDERS = {"minimax"}
+
+
+def _detect_provider() -> str:
+    """Auto-detect provider from environment variables."""
+    explicit = os.environ.get("LLM_PROVIDER", "").strip().lower()
+    if explicit:
+        return explicit
+
+    if os.environ.get("MINIMAX_API_KEY"):
+        return "minimax"
+
+    return "openai"
+
+
+def create_llm() -> ChatOpenAI:
+    """
+    Create a ChatOpenAI-compatible LLM instance based on environment config.
+
+    Environment variables:
+        LLM_PROVIDER   – Provider name: "openai" | "minimax" (auto-detected if unset)
+        LLM_MODEL      – Model name (provider-specific default if unset)
+        LLM_BASE_URL   – Custom base URL (overrides provider preset)
+        LLM_TEMPERATURE – Temperature value (default: 0.7)
+        OPENAI_API_KEY  – OpenAI API key
+        MINIMAX_API_KEY – MiniMax API key
+    """
+    provider = _detect_provider()
+    preset = PROVIDER_PRESETS.get(provider, {})
+
+    model = os.environ.get("LLM_MODEL") or preset.get("default_model") or "gpt-5.4-2026-03-05"
+    base_url = os.environ.get("LLM_BASE_URL") or preset.get("base_url")
+
+    # Resolve API key
+    api_key_env = preset.get("api_key_env", "OPENAI_API_KEY")
+    api_key = os.environ.get(api_key_env) or os.environ.get("OPENAI_API_KEY", "")
+
+    # Parse temperature
+    temperature = float(os.environ.get("LLM_TEMPERATURE", "0.7"))
+
+    # Clamp temperature for providers that require it (MiniMax: (0.0, 1.0])
+    if provider in _CLAMP_TEMPERATURE_PROVIDERS:
+        temperature = max(0.01, min(temperature, 1.0))
+
+    kwargs = {
+        "model": model,
+        "temperature": temperature,
+    }
+
+    if base_url:
+        kwargs["base_url"] = base_url
+
+    if api_key:
+        kwargs["api_key"] = api_key
+
+    return ChatOpenAI(**kwargs)

apps/agent/tests/__init__.py

@@ -0,0 +1,26 @@
+"""Configure imports so tests can import from the agent src directory."""
+
+import importlib
+import sys
+import types
+from pathlib import Path
+
+# The system has a `src` package installed globally that shadows our local
+# `src/` directory. Remove it so that the agent's own `src` package is found.
+agent_root = Path(__file__).resolve().parents[1]
+src_dir = agent_root / "src"
+
+# Remove any pre-existing `src` module from the cache
+for key in list(sys.modules):
+    if key == "src" or key.startswith("src."):
+        del sys.modules[key]
+
+# Ensure agent root is first on the path
+if str(agent_root) not in sys.path:
+    sys.path.insert(0, str(agent_root))
+
+# Register our local src as a namespace package so submodule imports work
+src_mod = types.ModuleType("src")
+src_mod.__path__ = [str(src_dir)]
+src_mod.__package__ = "src"
+sys.modules["src"] = src_mod