diff --git a/experiments/analysis-efficiency/agent-trial.py b/experiments/analysis-efficiency/agent-trial.py
index 824cb43dab..8fbd1eff1a 100644
--- a/experiments/analysis-efficiency/agent-trial.py
+++ b/experiments/analysis-efficiency/agent-trial.py
@@ -99,6 +99,8 @@ def main():
                         help='Opt-in exact-name discovery guidance for selected REA tools')
     parser.add_argument('--normalize-mcp-guidance', action='store_true',
                         help='Opt-in common envelope/stopping guidance, identical across protocol lanes')
+    parser.add_argument('--guide-long-waits', action='store_true',
+                        help='Opt-in common client wait guidance; does not change analysis contracts or deadlines')
     args = parser.parse_args()
     if args.guide_enabled_tools and args.enabled_tools is None:
         parser.error('--guide-enabled-tools requires --enabled-tools')
@@ -235,6 +237,15 @@ def main():
             'return only their metadata. Preserve the original analyst question, '
             'dependency order and source Evidence.'
         )
+    if args.guide_long_waits:
+        instruction += (
+            ' When the client executor reports a running cell during a long analysis, '
+            'resume that same cell with wait and yield_time_ms:30000, within the '
+            'advertised tool schema, rather than repeated one-second polls. '
+            'The wait may return early when the result is ready. Do not sleep or '
+            'start duplicate analysis calls just to check completion. Keep the '
+            'original analysis dependencies, evidence and stopping requirements.'
+        )
     quote = json.dumps
     config = '\n'.join([
         'approval_policy = "never"', 'sandbox_mode = "read-only"',
@@ -290,6 +301,7 @@ def main():
             'capture_tool_context': args.capture_tool_context,
             'guide_enabled_tools': args.guide_enabled_tools,
             'normalize_mcp_guidance': args.normalize_mcp_guidance,
+            'guide_long_waits': args.guide_long_waits,
             'driver_commit': subprocess.check_output(
                 ['git', 'rev-parse', 'HEAD'], cwd=driver_repository, text=True).strip(),
             'runtime_revision': args.revision,
diff --git a/experiments/atomic-codemode/client-wait-study.md b/experiments/atomic-codemode/client-wait-study.md
new file mode 100644
index 0000000000..f454c3a2aa
--- /dev/null
+++ b/experiments/atomic-codemode/client-wait-study.md
@@ -0,0 +1,51 @@
+# Client waiting and whole-task cost
+
+The [selected-case pair](switch-study.md) exposes one-second client polls after
+the snapshot execution yields. Direct makes six waits (three one-second then
+three ten-second requests); Code Mode makes three one-second requests. Five
+direct and two Code Mode wait responses still report a running cell. Initial
+execution yields after about 31 seconds in both lanes. This is observed client
+behavior, separate from MCP attempts and native source-capture time.
+
+Native latency remains variable, including in sequential scripted MCP runs
+without models. The [overlap canary](overlap-study.md) did not establish a cause.
+No analysis acceleration or cache invalidation change is proposed here.
+
+## Frozen diagnostic
+
+The opt-in runner flag `--guide-long-waits` appends exactly the same client wait
+policy in both lanes: resume an already-running cell with a 30,000 ms wait,
+respect the advertised schema, and do not sleep or duplicate analysis merely
+to check progress. It changes neither the initial execution yield policy nor
+the provider/Code Mode deadlines. It supplies no analysis facts. The policy,
+flag and instruction digest are recorded in each trial's settings. Older runs
+without this flag remain a separate stratum.
+
+Run Code Mode first, then direct, with the unchanged
+[question](sqlite-switch-question.txt) and [oracle](switch-oracle.md), final
+`a9ca8a8a...` engine, complete four/eighteen-tool catalogs and the same exact
+discovery/envelope guidance as the first pair. Use fresh leases and isolated
+model workspaces, requested `gpt-6.1-sol/high`, Codex 0.161.0 and the same one-CPU,
+4 GiB hard / 3 GiB early-stop resource policy. No runtime edits during the pair.
+Local records use `sqlite-switch-{codemode,direct}-v2*`.
+
+Review complete answers against the frozen independent machine oracle and
+retained source, including selector widths, all requested cases, signed target
+arithmetic, case/edge identities, native default versus machine out-of-range
+guard, provenance and unknown runtime behavior. Require one VM capture and
+focused reads; a lower token count without a correct answer is not a win.
+
+Record actual wait arguments and running/completed responses, model responses,
+all input/cached/uncached/output/reasoning tokens, MCP/API attempts, wall time,
+family CPU, kernel family peak, native source-capture time, identity/freshness
+and cleanup/OOM status. Count discovery, guidance and unsuccessful waits in
+whole-task usage. Fewer polls would establish adherence in this client, not
+causally lower tokens or native latency. A before/after pair remains subject to
+model choices, prompt caches, host contention and run order; do not subtract
+native or polling intervals to manufacture an adapter speedup.
+
+The [official Codex CLI reference](https://learn.chatgpt.com/docs/cli/reference)
+documents client configuration but does not establish the `wait` contract used
+here. The actual captured client calls and subsequent run establish behavior;
+no configuration feature flag is treated as proof of the available surface.
+The native/API contracts are unchanged. Results are pending.