Enforce bounded operation guardrails

Assistant: codex
Assistant-Model: gpt-5.6-sol
Assistant-Session: 01a028de-e2c8-7732-8521-46a7fc5db82f

src/activity_core/audit_projection.py

@@ -0,0 +1,68 @@
+"""Bounded, non-secret projections for durable audit surfaces."""
+
+from __future__ import annotations
+
+from typing import Any
+
+_SENSITIVE_KEYS = frozenset(
+    {
+        "api_key",
+        "api_token",
+        "access_token",
+        "refresh_token",
+        "authorization",
+        "client_secret",
+        "cookie",
+        "credential",
+        "credentials",
+        "messages",
+        "model_messages",
+        "password",
+        "private_key",
+        "provider_payload",
+        "provider_response",
+        "raw_output",
+        "raw_output_preview",
+        "raw_prompt",
+        "rendered_prompt",
+        "secret",
+        "token",
+        "tool_error",
+        "tool_output",
+    }
+)
+
+
+def bounded_audit_projection(
+    value: Any,
+    *,
+    max_depth: int = 8,
+    max_items: int = 100,
+    max_string: int = 4000,
+) -> Any:
+    """Return a JSON-like audit projection without raw or credential fields.
+
+    The projection is intentionally lossy. Workflow evaluation uses the full
+    in-memory context; only the durable audit copy is bounded here.
+    """
+
+    def project(item: Any, depth: int) -> Any:
+        if depth > max_depth:
+            return "<depth-limit>"
+        if item is None or isinstance(item, (bool, int, float)):
+            return item
+        if isinstance(item, str):
+            return item[:max_string]
+        if isinstance(item, dict):
+            result: dict[str, Any] = {}
+            for raw_key, child in list(item.items())[:max_items]:
+                key = str(raw_key)
+                if key.strip().lower() in _SENSITIVE_KEYS:
+                    continue
+                result[key] = project(child, depth + 1)
+            return result
+        if isinstance(item, (list, tuple)):
+            return [project(child, depth + 1) for child in item[:max_items]]
+        return str(item)[:max_string]
+
+    return project(value, 0)