Ready for first real test

tools/sandbox.py

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+"""Analyst script sandbox — run_analysis.
+
+Lets an agent write and run a real Python analysis script (pandas/numpy/yfinance/matplotlib)
+like a research analyst: fetch data, compute indicators/stats/backtests, save charts. Runs in
+a throwaway temp workdir with a **scrubbed environment** (no ALPACA_/FINNHUB_/OMLX_ secrets —
+model-generated code must never see keys), a wall-clock timeout, and network access (for data).
+
+Security posture (honest): running model-written networked code is a real surface. Mitigations:
+scrubbed env (no secrets), isolated temp workdir (no repo writes), wall-clock timeout, truncated
+output. Acceptable on a personal machine + local model; not a hardened multi-tenant sandbox.
+"""
+
+from __future__ import annotations
+
+import os
+import subprocess
+import sys
+import tempfile
+from pathlib import Path
+
+from langchain_core.tools import tool
+
+from config.settings import get_settings
+
+_STDOUT_LIMIT = 4000
+_SECRET_PREFIXES = ("ALPACA", "FINNHUB", "OMLX", "EMAIL", "SMTP", "OPENAI", "ANTHROPIC")
+_ARTIFACT_EXTS = {".png", ".jpg", ".jpeg", ".svg", ".csv", ".txt", ".html", ".md", ".json"}
+
+
+def scrubbed_env(home: str) -> dict[str, str]:
+    """A minimal environment with NO secrets — built from scratch, not inherited."""
+    env = {
+        "PATH": os.environ.get("PATH", "/usr/bin:/bin"),
+        "HOME": home,
+        "TMPDIR": home,
+        "LANG": os.environ.get("LANG", "en_US.UTF-8"),
+        "MPLBACKEND": "Agg",  # headless matplotlib
+        "MPLCONFIGDIR": home,
+    }
+    # defensive: never leak anything secret-looking even if the whitelist grows
+    return {k: v for k, v in env.items() if not k.upper().startswith(_SECRET_PREFIXES)}
+
+
+@tool
+def run_analysis(code: str) -> str:
+    """Run a Python analysis script and return its stdout plus any files it wrote.
+
+    Available: pandas, numpy, yfinance (data), matplotlib (charts, Agg), scipy. Use this like a
+    real analyst: fetch data with yfinance, compute indicators/stats/backtests, and save charts
+    with `plt.savefig("chart.png")`. You MUST print() anything you want to read back. Runs in an
+    isolated temp dir with a ~90s limit and NO access to account secrets.
+
+    Example:
+        import yfinance as yf, matplotlib.pyplot as plt
+        df = yf.download("AAPL", period="6mo")
+        df["SMA50"] = df["Close"].rolling(50).mean()
+        print(df[["Close","SMA50"]].tail())
+        df[["Close","SMA50"]].plot(); plt.savefig("aapl.png")
+    """
+    s = get_settings()
+    s.ensure_dirs()
+    workdir = Path(tempfile.mkdtemp(dir=s.sandbox_dir))
+    (workdir / "script.py").write_text(code)
+    # shared, persistent matplotlib cache so the font cache is built once (not per run) and
+    # doesn't land in each run's artifact list
+    mpl_cache = s.sandbox_dir / ".mplconfig"
+    mpl_cache.mkdir(parents=True, exist_ok=True)
+    env = scrubbed_env(str(workdir))
+    env["MPLCONFIGDIR"] = str(mpl_cache)
+    try:
+        proc = subprocess.run(
+            [sys.executable, "script.py"],
+            cwd=workdir,
+            env=env,
+            capture_output=True,
+            text=True,
+            timeout=s.sandbox_timeout_s,
+        )
+    except subprocess.TimeoutExpired:
+        return f"ERROR: analysis timed out ({s.sandbox_timeout_s}s limit)."
+    except Exception as e:  # pragma: no cover - defensive
+        return f"ERROR: {type(e).__name__}: {e}"
+
+    out = (proc.stdout or "").strip()
+    err = (proc.stderr or "").strip()
+    artifacts = [
+        str(p) for p in sorted(workdir.iterdir())
+        if p.is_file() and p.name != "script.py" and p.suffix.lower() in _ARTIFACT_EXTS
+    ]
+
+    if proc.returncode != 0:
+        return f"ERROR (exit {proc.returncode}): {err[-1500:] or 'no stderr'}"
+    result = out[:_STDOUT_LIMIT] or "(no stdout — did you print()?)"
+    if len(out) > _STDOUT_LIMIT:
+        result += "\n...[truncated]"
+    if err:
+        result += f"\n[stderr] {err[-400:]}"
+    if artifacts:
+        result += "\nArtifacts written: " + ", ".join(artifacts)
+    return result