Add key-free MCP tools, human approvals and opt-in assistant

ui/frame_assistant.py

@@ -0,0 +1,53 @@
+"""Explicit, per-request forwarding to a user-chosen chat-completions endpoint."""
+import base64
+import json
+from urllib.parse import urlsplit
+from urllib.request import HTTPRedirectHandler, ProxyHandler, Request, build_opener
+
+
+class NoRedirect(HTTPRedirectHandler):
+    def redirect_request(self, *args, **kwargs):
+        raise ValueError('Endpoint redirected; enter its final URL explicitly')
+
+
+def chat(body, screenshot):
+    if body.get('consent') is not True:
+        raise ValueError('Opt in before sending a message')
+    endpoint, model, prompt = (body.get(k) for k in ('endpoint', 'model', 'prompt'))
+    if any(not isinstance(v, str) or not v.strip() for v in (endpoint, model, prompt)):
+        raise ValueError('Endpoint, model and message are required')
+    if len(prompt) > 32000 or len(model) > 200 or len(endpoint) > 2048:
+        raise ValueError('Message, model or endpoint is too long')
+    url = urlsplit(endpoint)
+    if not url.hostname or url.username or url.password or url.fragment or url.query:
+        raise ValueError('Use an endpoint URL without credentials, query or fragment')
+    if url.scheme != 'https' and not (url.scheme == 'http' and url.hostname in ('localhost', '127.0.0.1', '::1')):
+        raise ValueError('Use HTTPS, or HTTP on loopback for a local model')
+    key = body.get('key', '')
+    if not isinstance(key, str) or len(key) > 4096 or '\n' in key or '\r' in key:
+        raise ValueError('Invalid API key')
+    content = prompt
+    if body.get('screenshot') is True:
+        png = screenshot()
+        if len(png) > 12 * 1024**2:
+            raise ValueError('Screenshot is too large')
+        content = [{'type': 'text', 'text': prompt}, {'type': 'image_url', 'image_url': {
+            'url': 'data:image/png;base64,' + base64.b64encode(png).decode()}}]
+    payload = {'model': model, 'messages': [{'role': 'user', 'content': content}], 'stream': False}
+    headers = {'Content-Type': 'application/json'}
+    if key:
+        headers['Authorization'] = 'Bearer ' + key
+    request = Request(endpoint, data=json.dumps(payload).encode(), headers=headers)
+    # No environment proxy or redirects: credentials/context go only to the chosen URL.
+    try:
+        with build_opener(ProxyHandler({}), NoRedirect()).open(request, timeout=60) as response:
+            raw = response.read(2 * 1024**2 + 1)
+        if len(raw) > 2 * 1024**2:
+            raise ValueError('Endpoint response is too large')
+        answer = json.loads(raw)['choices'][0]['message']['content']
+        if not isinstance(answer, str):
+            raise ValueError('Expected a text reply')
+    except Exception:
+        # Provider error bodies and URLs can contain credentials or echoed prompts.
+        raise ValueError('Endpoint request failed or returned an unsupported reply; check URL, model and credentials') from None
+    return {'reply': answer}