@@ -30,7 +30,9 @@ From `edgacknowledg.client` (`__all__`):
 - `ConnectionStatusListener` — `connected` / `attempting_reconnect` /
   `disconnected`
 - `ReviewClient` (structural **Protocol**): `review_id`, `name`, `timestamp`,
-  `sections()`, `add_section` / `remove_section`
+  `sections()`, `add_section` / `remove_section`. `name` is a `RichName`
+  (segments built with `rich_text` / `rich_link` from `edgacknowledg`; see
+  PROTOCOL.md "Rich names"); a plain title is `[rich_text(title)]`
 - URL/env helpers: `add_endpoint_arguments`, `form_section_http_url`,
   `default_*` host/port helpers
 - Shared: `BackgroundWorkerPool`, errors
 
@@ -16,7 +16,7 @@
 # Host, paths, and credentials come from secrets in the `acknowledg`
 # environment (see dev_tools/services/acknowledg/README.md). The SSH setup
 # writes them into a `Host acknowledg` alias so they never appear on a command
-# line.
+# line. The public API URL is the ACKNOWLEDG_API_HOST repository variable.
 
 name: AcknowlEDG Deploy
 
@@ -61,7 +61,7 @@ jobs:
       - name: Build client
         working-directory: ${{ env.ACKNOWLEDG_DIR }}/client
         env:
-          VITE_EDG_ACKNOWLEDG_API_HOST: ${{ secrets.ACKNOWLEDG_API_HOST }}
+          VITE_EDG_ACKNOWLEDG_API_HOST: ${{ vars.ACKNOWLEDG_API_HOST }}
         run: |
           # The client opens `${VITE_EDG_ACKNOWLEDG_API_HOST}/review`; without
           # a scheme the browser resolves that relative to the page instead.
 
@@ -21,7 +21,10 @@ import edgutil
 from edgacknowledg import (
   IncompatibleProtocolVersion,
   is_ui_section_type,
+  is_valid_rich_name,
   review_display_name,
+  rich_name_text,
+  rich_text,
   section_slug,
   utc_now_iso,
 )
@@ -41,7 +44,7 @@ from edgacknowledg.client.bench import (
   BenchSourceHandler,
   resolve_baseline_dir,
 )
-from edgacknowledg.client.shared import ReviewClientHandler
+from edgacknowledg.client.shared import ReviewClientHandler, SandboxContext
 from edgacknowledg.client.test import TestEditHandler, TestSourceHandler
 from edgutil import eprint
 
@@ -96,10 +99,13 @@ def _make_bench_session(parameters: Dict[str, Any],
   if session is not None:
     return session
 
+  # The run (which may lie elsewhere) and the bench home are all a review
+  # may read.
+  context = SandboxContext(bench_home, root)
   session = BenchReviewSession(
-    bench_home = bench_home,
-    run_dir = root,
-    baseline_dir = resolve_baseline_dir(bench_home, tag),
+    context = context,
+    run_dir = context.subpath(root),
+    baseline_dir = resolve_baseline_dir(context.subpath(bench_home), tag),
     tag = tag,
     threshold_slow = float(
       parameters.get('slower_threshold', DEFAULT_THRESHOLD_SLOW)
@@ -131,11 +137,16 @@ def _make_handler(section: Dict[str, Any],
   if section_type == 'test.src':
     if test_home is None:
       raise ValueError('test home required for test.src sections')
+    root = Path(parameters['root'])
+    # The run (which may lie elsewhere) and the test home are all a review
+    # may read.
+    context = SandboxContext(test_home, root)
     return TestSourceHandler(
       section_name,
       slug,
-      test_home,
-      Path(parameters['root'])
+      context,
+      context.subpath(test_home),
+      context.subpath(root)
     )
   if section_type == 'test.edit':
     return TestEditHandler(section_name, slug, worker_pool)
@@ -161,9 +172,17 @@ async def build_review_client(session: BatchClientSession,
   if 'id' not in raw:
     raise ValueError('review is missing required field "id"')
 
+  # A plain title, or a rich name (see PROTOCOL.md).
+  name = raw.get('name')
+  if isinstance(name, list):
+    if not is_valid_rich_name(name):
+      raise ValueError('review "name" is not a valid rich name')
+  else:
+    name = [rich_text(review_display_name(name))]
+
   review = await session.create_review(
     uuid.UUID(str(raw['id'])),
-    review_display_name(raw.get('name')),
+    name,
     str(raw.get('timestamp') or utc_now_iso())
   )
 
@@ -254,7 +273,8 @@ def main() -> None:
               session, raw, worker_pool
             )
             print_connection_status(
-              f"Serving review \"{review.name}\" ({review.review_id})."
+              f"Serving review \"{rich_name_text(review.name)}\" "
+              f"({review.review_id})."
             )
             print_section_urls(args.ui_hostname, args.ui_port, review)
         except (OSError, ValueError) as ex:
 
@@ -32,6 +32,7 @@ from edgacknowledg.client.bench import (
   BenchSourceHandler,
   resolve_baseline_dir,
 )
+from edgacknowledg.client.shared import SandboxContext
 from edgacknowledg import IncompatibleProtocolVersion
 from edgutil import eprint
 
@@ -166,14 +167,17 @@ def main() -> None:
     eprint(f"Path does not exist: {run_dir}")
     sys.exit(1)
 
-  baseline_dir = resolve_baseline_dir(bench_home, args.tag)
+  # The run (given with --root, it may lie elsewhere) and the bench home
+  # are all a review may read.
+  context = SandboxContext(bench_home, run_dir)
+  baseline_dir = resolve_baseline_dir(context.subpath(bench_home), args.tag)
   if not baseline_dir.exists():
     eprint(f"Baseline directory does not exist: {baseline_dir}")
     sys.exit(1)
 
   session = BenchReviewSession(
-    bench_home = bench_home,
-    run_dir = run_dir,
+    context = context,
+    run_dir = context.subpath(run_dir),
     baseline_dir = baseline_dir,
     tag = args.tag,
     threshold_slow = args.threshold_slow,
@@ -206,7 +210,7 @@ def main() -> None:
         status_listener = _CliConnectionStatusListener()
       ) as client_session:
         review = await client_session.create_review(
-          run_id, review_name, created_at
+          run_id, [edgacknowledg.rich_text(review_name)], created_at
         )
         await review.add_section(
           BenchSourceHandler(
 
@@ -23,6 +23,7 @@ from edgacknowledg.client import (
   add_endpoint_arguments,
   form_section_http_url,
 )
+from edgacknowledg.client.shared import SandboxContext
 from edgacknowledg.client.test import TestEditHandler, TestSourceHandler
 from edgacknowledg import IncompatibleProtocolVersion
 from edgutil import eprint
@@ -161,11 +162,18 @@ def main() -> None:
         status_listener = _CliConnectionStatusListener()
       ) as session:
         review = await session.create_review(
-          run_id, review_name, created_at
-        )
-        await review.add_section(
-          TestSourceHandler(args.section_name, slug, test_home, run_dir)
+          run_id, [edgacknowledg.rich_text(review_name)], created_at
         )
+        # The run (given with --root, it may lie elsewhere) and the test
+        # home are all a review may read.
+        context = SandboxContext(test_home, run_dir)
+        await review.add_section(TestSourceHandler(
+          args.section_name,
+          slug,
+          context,
+          context.subpath(test_home),
+          context.subpath(run_dir)
+        ))
         await review.add_section(
           TestEditHandler(args.section_name, slug, worker_pool)
         )
 
@@ -10,7 +10,8 @@
 
 from collections.abc import Mapping
 from datetime import datetime, timezone
-from typing import Any, Dict, FrozenSet, Optional, Tuple, Union
+from typing import Any, Dict, FrozenSet, List, Optional, Tuple, Union
+from urllib.parse import urlsplit
 
 # If you change these values, make sure to update the JavaScript client code.
 #
@@ -26,6 +27,9 @@ class RequestTags:
   INVALID_REQUEST = 'invalid'
   OUTDATED_PROTOCOL = 'outdated-proto'
   ROLE_OCCUPIED = 'role-occupied'
+  # A reviewer asked a provider for a file it may not read: provider ->
+  # server (naming the reviewer), which closes that reviewer's connection.
+  ILLEGAL_ACCESS = 'illegal-access'
   META_SECTION_NAME = 'meta.section.name'
   META_REVIEW_NAME = 'meta.review.name'
   META_REVIEW_TIMESTAMP = 'meta.review.timestamp'
@@ -117,7 +121,7 @@ def request_tags_with_prefix(prefix: str) -> FrozenSet[str]:
   ALLOWED_BENCH_EDIT_TAGS
 )
 
-PROTOCOL_REVISION = 18
+PROTOCOL_REVISION = 19
 
 # 10MiB
 MAX_MESSAGE_SIZE = 10485760
@@ -140,6 +144,72 @@ def review_display_name(name: Optional[str] = None) -> str:
   from edgdocker import render_user_name
   return f"Review opened by {render_user_name()}"
 
+# A review's name is rich text: segments composed in order, each either
+# {'type': 'text', 'text': ...} or {'type': 'link', 'url': ..., 'text': ...}
+# (a link's text is optional; its URL is shown without it). See PROTOCOL.md.
+RichName = List[Dict[str, str]]
+
+MAX_RICH_NAME_SEGMENTS = 32
+# Characters, across every segment's text and URL.
+MAX_RICH_NAME_LENGTH = 4096
+
+_RICH_SEGMENT_FIELDS = {
+  'text': ({'type', 'text'}, {'type', 'text'}),
+  'link': ({'type', 'url'}, {'type', 'url', 'text'}),
+}
+
+def rich_text(text: str) -> Dict[str, str]:
+  return {'type': 'text', 'text': text}
+
+def rich_link(url: str, text: Optional[str] = None) -> Dict[str, str]:
+  segment = {'type': 'link', 'url': url}
+  if text is not None:
+    segment['text'] = text
+  return segment
+
+def _is_web_url(url: str) -> bool:
+  try:
+    parts = urlsplit(url)
+  except ValueError:
+    return False
+  return parts.scheme in ('http', 'https') and parts.netloc != ''
+
+def is_valid_rich_name(value: Any) -> bool:
+  '''Return whether ``value`` is a well-formed rich name: a non-empty list
+  of known segments with only their fields, all non-empty strings, and
+  links only to http(s) URLs, within the size limits.
+  '''
+  if not isinstance(value, list):
+    return False
+  if len(value) == 0 or len(value) > MAX_RICH_NAME_SEGMENTS:
+    return False
+  length = 0
+  for segment in value:
+    if not isinstance(segment, dict):
+      return False
+    segment_type = segment.get('type')
+    if segment_type not in _RICH_SEGMENT_FIELDS:
+      return False
+    required, allowed = _RICH_SEGMENT_FIELDS[segment_type]
+    keys = set(segment)
+    if not (required <= keys <= allowed):
+      return False
+    for key, field in segment.items():
+      if not isinstance(field, str) or field == '':
+        return False
+      if key != 'type':
+        length += len(field)
+    if segment['type'] == 'link' and not _is_web_url(segment['url']):
+      return False
+  return length <= MAX_RICH_NAME_LENGTH
+
+def rich_name_text(name: RichName) -> str:
+  '''Return ``name`` as plain text (e.g. for terminal output).'''
+  return ''.join(
+    segment['text'] if segment.get('text') else segment.get('url', '')
+    for segment in name
+  )
+
 def utc_now_iso() -> str:
   '''Return the current UTC time as an ISO-8601 timestamp.'''
   return datetime.now(timezone.utc).isoformat()