add grader_fn to tasks endpoint

sql_env/server.py

@@ -6,11 +6,10 @@ Exposes the OpenEnv-required endpoints: /reset, /step, /state + /tasks for valid
 
 from contextlib import asynccontextmanager
 from typing import Optional
-
 from fastapi import FastAPI, HTTPException
 from fastapi.middleware.cors import CORSMiddleware
 from pydantic import BaseModel
-
+from openenv.core.env_server import Environment
 from sql_env import SQLAction, SQLCorrectionEnv
 from sql_env.tasks import ALL_TASKS
 
@@ -99,12 +98,39 @@ async def health():
 
 @app.get("/tasks")
 async def list_tasks():
-    """Return graded tasks by difficulty (RL validator format)."""
-    graded_tasks = {
-        diff: [task.__dict__ for task in tasks if task.grader is not None]
-        for diff, tasks in ALL_TASKS.items()
+    """Return graded tasks in openenv validator format."""
+    from sql_env.grader import grade
+    return {
+        "tasks": [
+            {
+                "name": "easy",
+                "difficulty": "easy",
+                "description": "Fix a single syntax error. Error hint provided.",
+                "max_steps": 5,
+                "has_grader": True,
+                "grader": "sql_env.grader.grade",
+                "grader_fn": grade.__module__ + "." + grade.__qualname__,
+            },
+            {
+                "name": "medium",
+                "difficulty": "medium",
+                "description": "Fix multiple errors. No hint.",
+                "max_steps": 5,
+                "has_grader": True,
+                "grader": "sql_env.grader.grade",
+                "grader_fn": grade.__module__ + "." + grade.__qualname__,
+            },
+            {
+                "name": "hard",
+                "difficulty": "hard",
+                "description": "Fix complex multi-join queries. Schema provided.",
+                "max_steps": 4,
+                "has_grader": True,
+                "grader": "sql_env.grader.grade",
+                "grader_fn": grade.__module__ + "." + grade.__qualname__,
+            },
+        ]
     }
-    return graded_tasks  # {"easy": [tasks], "medium": [tasks], "hard": [tasks]}
 
 
 @app.get("/")