diff --git a/package.json b/package.json
index 33b90b8..7cb300f 100644
--- a/package.json
+++ b/package.json
@@ -18,7 +18,7 @@
   },
   "dependencies": {
     "@haverstack/adapter-local": "^0.6.0",
-    "@haverstack/core": "^0.6.0",
+    "@haverstack/core": "^0.8.0",
     "@haverstack/wire-types": "^0.6.0",
     "@hono/node-server": "^1.13.7",
     "hono": "^4.6.0",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index a2e4844..f4c0b0f 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -12,8 +12,8 @@ importers:
         specifier: ^0.6.0
         version: 0.6.0
       '@haverstack/core':
-        specifier: ^0.6.0
-        version: 0.6.0
+        specifier: ^0.8.0
+        version: 0.8.0
       '@haverstack/wire-types':
         specifier: ^0.6.0
         version: 0.6.0
@@ -410,6 +410,9 @@ packages:
   '@haverstack/core@0.6.0':
     resolution: {integrity: sha512-ruv1LrOlCaCgQTfUKbQEi3hYeIxJ7fGHU2ynWPY3LjB5Cia+bbMkAnPtznEparunPNhOfdI/nf51MjMwyhFhkg==}
 
+  '@haverstack/core@0.8.0':
+    resolution: {integrity: sha512-QT4YvvpZRwHILJCUAsIA28Ed043/nTP97+njEFAr3fOb3B2kCGT14WCdobCjCy4y2uX6ziwch7/lzGlmfirI8Q==}
+
   '@haverstack/record-adapter-sqljs@0.6.0':
     resolution: {integrity: sha512-+BHfNqW+dKg0Yy+io6cvqXjrOWugBXbPtQJWKTI9VNA6zfHngoWPpYIJ9n01dQ8LpsorXaRAG0ROO3Fev9mI6Q==}
 
@@ -1515,6 +1518,8 @@ snapshots:
 
   '@haverstack/core@0.6.0': {}
 
+  '@haverstack/core@0.8.0': {}
+
   '@haverstack/record-adapter-sqljs@0.6.0':
     dependencies:
       '@haverstack/core': 0.6.0
diff --git a/src/middleware/errors.ts b/src/middleware/errors.ts
index 2cd45bc..6460b61 100644
--- a/src/middleware/errors.ts
+++ b/src/middleware/errors.ts
@@ -1,12 +1,18 @@
 import type { ErrorHandler } from 'hono';
 import type { Logger } from 'pino';
 import type { AppEnv } from '../types.js';
-import { StackPermissionError, StackValidationError, StackNotFoundError } from '@haverstack/core';
+import {
+  StackPermissionError,
+  StackValidationError,
+  StackNotFoundError,
+  StackConflictError,
+} from '@haverstack/core';
 
 export function errorMiddleware(logger: Logger): ErrorHandler<AppEnv> {
   return (err, c) => {
     if (err instanceof StackNotFoundError) return c.json({ error: 'Not found' }, 404);
     if (err instanceof StackPermissionError) return c.json({ error: 'Forbidden' }, 403);
+    if (err instanceof StackConflictError) return c.json({ error: err.message }, 409);
     if (err instanceof StackValidationError)
       return c.json({ error: err.message, details: err.errors }, 422);
     logger.error({ err, requestId: c.get('requestId') }, 'Unhandled request error');
diff --git a/src/routes/attachments.ts b/src/routes/attachments.ts
index 160272d..d27684a 100644
--- a/src/routes/attachments.ts
+++ b/src/routes/attachments.ts
@@ -1,5 +1,5 @@
 import { Hono } from 'hono';
-import { SYSTEM_TYPES } from '@haverstack/core';
+import { StackPermissionError } from '@haverstack/core';
 import type { AppEnv } from '../types.js';
 import type { StackContext } from '../stack.js';
 import { requireAuth, requireOwner } from '../middleware/auth.js';
@@ -33,13 +33,11 @@ export function attachmentRoutes(ctx: StackContext, maxAttachmentBytes: number):
     const fileId = c.req.param('fileId');
     const auth = c.get('auth');
 
-    const accessible = await isAttachmentAccessible(fileId, auth?.entityId ?? null, ctx);
-    if (!accessible) return c.json({ error: 'Unauthorized' }, 401);
-
     let data: Uint8Array;
     try {
-      data = await adapter.getAttachment(fileId);
-    } catch {
+      data = await stack.asEntity(auth?.entityId ?? null).getAttachment(fileId);
+    } catch (e) {
+      if (e instanceof StackPermissionError) return c.json({ error: 'Unauthorized' }, 401);
       return c.json({ error: 'Attachment not found' }, 404);
     }
 
@@ -63,32 +61,7 @@ export function attachmentRoutes(ctx: StackContext, maxAttachmentBytes: number):
   // DELETE /attachments/:fileId
   app.delete('/:fileId', requireOwner(ownerEntityId), async (c) => {
     const fileId = c.req.param('fileId');
-
-    // Find any _attachment@1 metadata record(s) for this file
-    const metaResult = await stack.query({
-      filter: { typeId: `${SYSTEM_TYPES.ATTACHMENT}@1`, content: { fileId } },
-    });
-
-    // If no metadata record, verify the bytes actually exist before proceeding
-    if (!metaResult.records.length) {
-      try {
-        await adapter.getAttachment(fileId);
-      } catch {
-        return c.json({ error: 'Attachment not found' }, 404);
-      }
-    }
-
-    // Refuse if any record in the stack still references this file
-    const refResult = await stack.query({ filter: { attachmentFileId: fileId }, limit: 1 });
-    if (refResult.records.length > 0) {
-      return c.json({ error: 'Attachment is still referenced by one or more records' }, 409);
-    }
-
-    for (const record of metaResult.records) {
-      await stack.delete(record.id, { hard: true });
-    }
-
-    await adapter.deleteAttachment(fileId);
+    await stack.deleteAttachment(fileId);
     return c.body(null, 204);
   });
 
@@ -143,40 +116,3 @@ function resolveMimeType(declared: string, filename: string | undefined): string
   const ext = filename.split('.').pop()?.toLowerCase();
   return (ext && EXTENSION_MIME[ext]) || declared;
 }
-
-/**
- * An attachment is accessible if:
- * 1. The requester is the stack owner, OR
- * 2. The requester can read at least one Record that references the file, OR
- * 3. The requester uploaded the file (owns its _attachment@1 record) and it
- *    hasn't been associated with any record yet.
- */
-async function isAttachmentAccessible(
-  fileId: string,
-  requesterEntityId: string | null,
-  ctx: StackContext,
-): Promise<boolean> {
-  const { stack } = ctx;
-  if (requesterEntityId && requesterEntityId === stack.ownerEntityId) return true;
-
-  const result = await stack.asEntity(requesterEntityId).query({
-    filter: { attachmentFileId: fileId },
-    limit: 1,
-  });
-  if (result.records.length > 0) return true;
-
-  // Unassociated file: check if the requester uploaded it
-  if (requesterEntityId) {
-    const uploadResult = await stack.query({
-      filter: {
-        typeId: `${SYSTEM_TYPES.ATTACHMENT}@1`,
-        entityId: requesterEntityId,
-        content: { fileId },
-      },
-      limit: 1,
-    });
-    if (uploadResult.records.length > 0) return true;
-  }
-
-  return false;
-}