diff --git a/README.md b/README.md
index bc2c814..fb10fdc 100644
--- a/README.md
+++ b/README.md
@@ -36,9 +36,12 @@ Interactive docs: http://localhost:8100/docs
 | POST | `/runs` | Start a rendering run |
 | GET | `/runs` | List all runs |
 | GET | `/runs/{run_id}` | Get run status |
+| DELETE | `/runs/{run_id}` | Delete a run |
 | GET | `/cache` | List cached content hashes |
 | GET | `/cache/{hash}` | Download cached content |
+| DELETE | `/cache/{hash}` | Delete cached content |
 | POST | `/cache/import?path=` | Import local file to cache |
+| POST | `/cache/upload` | Upload file to cache |
 | GET | `/assets` | List known assets |
 
 ### Start a run
@@ -55,6 +58,24 @@ curl -X POST http://localhost:8100/runs \
 curl http://localhost:8100/runs/{run_id}
 ```
 
+### Delete a run
+
+```bash
+curl -X DELETE http://localhost:8100/runs/{run_id} \
+  -H "Authorization: Bearer <token>"
+```
+
+Note: Failed runs can always be deleted. Completed runs can only be deleted if their outputs haven't been published to L2.
+
+### Delete cached content
+
+```bash
+curl -X DELETE http://localhost:8100/cache/{hash} \
+  -H "Authorization: Bearer <token>"
+```
+
+Note: Items that are inputs/outputs of runs, or published to L2, cannot be deleted.
+
 ## Storage
 
 - **Cache**: `~/.artdag/cache/` (content-addressed files)
diff --git a/cache_manager.py b/cache_manager.py
index da94050..d7b425b 100644
--- a/cache_manager.py
+++ b/cache_manager.py
@@ -243,33 +243,46 @@ class L1CacheManager:
 
     def get_by_content_hash(self, content_hash: str) -> Optional[Path]:
         """Get cached file path by content_hash."""
+        logger.info(f"get_by_content_hash({content_hash[:16]}...) - cache_dir={self.cache_dir}, nodes_dir={self.cache.cache_dir}")
+
         # Check index first (new cache structure)
         node_id = self._content_index.get(content_hash)
         if node_id:
+            logger.info(f"  Found in content_index: node_id={node_id[:16]}...")
             path = self.cache.get(node_id)
             if path and path.exists():
+                logger.info(f"  Found via index: {path}")
                 return path
+            logger.info(f"  Index entry but path not found: {path}")
 
         # For uploads, node_id == content_hash, so try direct lookup
         # This works even if cache index hasn't been reloaded
+        logger.info(f"  Trying direct lookup with content_hash as node_id...")
         path = self.cache.get(content_hash)
+        logger.info(f"  cache.get({content_hash[:16]}...) returned: {path}")
         if path and path.exists():
+            logger.info(f"  Found via direct lookup: {path}")
             self._content_index[content_hash] = content_hash
             self._save_content_index()
             return path
 
         # Scan cache entries (fallback for new structure)
+        logger.info(f"  Trying find_by_content_hash...")
         entry = self.cache.find_by_content_hash(content_hash)
         if entry and entry.output_path.exists():
+            logger.info(f"  Found via scan: {entry.output_path}")
             self._content_index[content_hash] = entry.node_id
             self._save_content_index()
             return entry.output_path
 
         # Check legacy location (files stored directly as CACHE_DIR/{content_hash})
         legacy_path = self.cache_dir / content_hash
+        logger.info(f"  Checking legacy path: {legacy_path}, exists={legacy_path.exists()}")
         if legacy_path.exists() and legacy_path.is_file():
+            logger.info(f"  Found at legacy location: {legacy_path}")
             return legacy_path
 
+        logger.info(f"  NOT FOUND anywhere")
         return None
 
     def has_content(self, content_hash: str) -> bool:
diff --git a/server.py b/server.py
index f1d06f6..d7191da 100644
--- a/server.py
+++ b/server.py
@@ -280,6 +280,42 @@ async def root():
     return HOME_HTML
 
 
+@app.get("/debug/cache/{content_hash}")
+async def debug_cache(content_hash: str):
+    """Debug endpoint to check cache status for a content hash."""
+    import os
+
+    result = {
+        "content_hash": content_hash,
+        "cache_dir": str(cache_manager.cache_dir),
+        "nodes_dir": str(cache_manager.cache.cache_dir),
+        "in_content_index": content_hash in cache_manager._content_index,
+        "node_id_from_index": cache_manager._content_index.get(content_hash),
+    }
+
+    # Check various locations
+    locations = {
+        "legacy_direct": cache_manager.cache_dir / content_hash,
+        "nodes_dir": cache_manager.cache.cache_dir / content_hash,
+    }
+
+    for name, path in locations.items():
+        result[f"{name}_path"] = str(path)
+        result[f"{name}_exists"] = path.exists()
+        if path.exists() and path.is_dir():
+            result[f"{name}_contents"] = [f.name for f in path.iterdir()]
+
+    # Check if artdag cache has it
+    result["artdag_cache_get"] = str(cache_manager.cache.get(content_hash))
+
+    # Check via cache_manager
+    found_path = cache_manager.get_by_content_hash(content_hash)
+    result["cache_manager_path"] = str(found_path) if found_path else None
+    result["has_content"] = cache_manager.has_content(content_hash)
+
+    return result
+
+
 @app.post("/runs", response_model=RunStatus)
 async def create_run(request: RunRequest, username: str = Depends(get_required_user)):
     """Start a new rendering run. Requires authentication."""