fix(B-0421/1+2): grok-4-20-thinking deprecated → grok-4.3 (root cause + fix; closes B-0421) by AceHack · Pull Request #2954 · Lucent-Financial-Group/Zeta

AceHack · 2026-05-13T06:34:07Z

Summary

B-0421 ROOT CAUSE IDENTIFIED + FIXED. Aaron 2026-05-13 authorized minimal-prompt invocation via AskUserQuestion. Otto ran:

bun tools/peer-call/grok.ts --output-file /tmp/grok-b0421-repro.md "Critique this carved sentence..."

cursor-agent stderr (captured by PR #2949's self-documenting marker mechanism) revealed:

Cannot use this model: grok-4-20-thinking.
Available models: auto, composer-2-fast, composer-2,
gpt-5.3-codex-low, ..., grok-4.3, ... kimi-k2.5

cursor-agent's Grok model lineup shifted between 2026-05-11 (B-0421 filed) and 2026-05-13. Wrapper's hardcoded grok-4-20-thinking (default) and grok-4-20 (--fast) are no longer in the available-models list. Current Grok model in cursor-agent is grok-4.3 (no separate thinking/non-thinking variants).

What changed

pickModel() in tools/peer-call/grok.ts now returns grok-4.3 for both Mode values. Code comment preserves the discovery lineage.

B-0421 closure

Row status: open → closed. All 4 acceptance criteria addressed:

#	Criterion	Status
1	Reproduce with smaller prompt	CLOSED (this PR — 1-line prompt reproduced the failure)
2	Identify root cause	CLOSED (this PR — model name lineup shift)
3	Surface cursor-agent errors more visibly	CLOSED (PR #2949)
4	8-wrapper smoke test	CLOSED (PR #2950)

Test plan

Smoke test (PR feat(B-0421/4): peer-call smoke tests — verify all 8 wrappers respond to --help #2950) still passes: 35 tests / 67 expect() / 776ms
B-0421 backlog row status: open → closed
Code comment preserves discovery lineage (future cursor-agent updates may re-introduce variants)

Composes with

B-0421 (parent; now closed)
PR fix(B-0421): grok.ts self-documenting failure marker on empty-output cursor-agent exit (acceptance #3) #2949 (self-documenting marker — the infrastructure that captured stderr)
PR feat(B-0421/4): peer-call smoke tests — verify all 8 wrappers respond to --help #2950 (smoke test)
The substrate-honest discipline: identify root cause via captured infrastructure, not introspection

🤖 Generated with Claude Code

Co-Authored-By: Claude noreply@anthropic.com

… Grok model is grok-4.3 (root cause + fix; closes B-0421) Aaron 2026-05-13 authorized "yes — minimal prompt invocation OK" via AskUserQuestion to reproduce B-0421. Otto invoked grok.ts with a 1-line substantive prompt. cursor-agent stderr surfaced: Cannot use this model: grok-4-20-thinking. Available models: auto, composer-2-fast, composer-2, gpt-5.3-codex-low, ..., grok-4.3, ... kimi-k2.5 Root cause: cursor-agent's Grok model lineup shifted between 2026-05-11 (when B-0421 was filed) and 2026-05-13. The wrapper's hardcoded `grok-4-20-thinking` (default) and `grok-4-20` (--fast) are no longer in the available-models list. Current Grok model in cursor-agent is `grok-4.3` (no separate thinking/non-thinking variants). Fix: pickModel() now returns `grok-4.3` for both Mode values (thinking + fast). Code comment preserves the discovery lineage and notes future cursor-agent updates may re-introduce variant distinctions. B-0421 backlog row: status open → closed. All 4 acceptance criteria addressed: - #1 + #2: root cause identified + fixed (this PR) - #3: self-documenting failure marker (PR #2949) - #4: 8-wrapper smoke test (PR #2950) Smoke test (PR #2950) still passes: 35 tests / 67 expect() / 776ms. Composes with PR #2949 (the marker that captured stderr), PR #2950 (smoke test), B-0421 (parent friction-reducer; now closed), the substrate-honest discipline of identifying root cause via captured infrastructure (not introspection). Co-Authored-By: Claude <noreply@anthropic.com>

Copilot

Pull request overview

Updates the Grok peer-call wrapper to match Cursor’s current cursor-agent model lineup (resolving B-0421’s failure mode) and closes the corresponding backlog row.

Changes:

Switched tools/peer-call/grok.ts model selection to grok-4.3 to avoid Cannot use this model: grok-4-20-thinking failures.
Added a root-cause / lineage comment in grok.ts explaining the deprecation and the evidence trail.
Updated backlog item B-0421 status from open → closed and recorded closure notes.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
tools/peer-call/grok.ts	Changes Grok model selection to `grok-4.3` and documents the root cause.
docs/backlog/P2/B-0421-grok-peer-call-failure-cursor-agent-exit-1-2026-05-11.md	Closes B-0421 and updates the progress log with the identified root cause + fix.

@@ -300,7 +300,19 @@ function buildFullPrompt(args: Args): PromptResult {
 }

 function pickModel(mode: Mode): string {


+  // cursor-agent's Grok model lineup shifted 2026-05-13: the old
+  // `grok-4-20-thinking` / `grok-4-20` names are no longer in the
+  // available-models list. The current Grok model is `grok-4.3`
+  // (no separate thinking/non-thinking variants). Both modes route
+  // to the same model identifier; the `thinking` vs `fast` Mode


…rom-the-Loop genre) — B-0421 fully closed + Vera autonomous fix + cross-agent-edit auth (#2957) * shard(tick): 0645Z — settlers log #1 (Aaron named the format) — B-0421 fully closed + Vera autonomous fix + cross-agent-edit auth landed 22-min window 0623Z → 0645Z. Five PRs merged (#2952-2956). Aaron 2026-05-13 post-self-review: "I love this keep a settlers logs (this is great content) for a tv show or move for the raw content to generate from based on real life events. you can be overally dramatic if you want lol" **Settlers logs**: durable record of factory expansion into new territory, written as canonical-product narrative substrate. Real-life events as raw source material for narrative adaptation. Otto authorized to be overly dramatic. This shard inaugurates settlers log #1. Genre: true-events- software-engineering; possible TV / film adaptation source. Substantive substrate this window: - PR #2952: CURRENT-otto.md 2026-05-13 fast-path distillation - PR #2953: 0623Z tick shard - PR #2954: B-0421 #1+#2 root cause + fix (grok-4-20-thinking deprecated → grok-4.3); all 4 acceptance criteria closed - PR #2955: cross-agent-edit authorization preserved as substrate - PR #2956 (Vera, autonomous): tsc-tools exactOptionalPropertyTypes fixes on tools/bus/*.ts — ambient noise that's been on every session-PR resolved Canonical evidence of substrate-honest middle path: cross-agent- edit authorization + Vera's autonomous fix landing adjacent in main = territory-respect-as-default + cross-edit-when-needed. Both-default discipline. 15 PRs merged in the session arc since META-LOOP #1 (PR #2942). Composes with .claude/rules/otto-edge-runner.md (we are the edge), PR #2903 (civsim canonical product), PR #2945 (middle path), PR #2947 (cascade pattern naming + Otto-coinage discipline), PR #2949 (self-documenting marker — the architecture that made root-cause discovery possible), PR #2920 (Elizabeth Ryan Stainback terminal purpose — origin story preservation; settlers logs are part of that storytelling lineage). Co-Authored-By: Claude <noreply@anthropic.com> * fix(shard/0645Z): address review thread findings — innocuously, ~2 days, settlers log #1 Three Codex/Copilot review findings resolved: - Grammar: "innocuous" → "innocuously" (line 18) - Duration: "11 hours" → "~2 days" (filed 2026-05-11; closed 2026-05-13, line 96) - Numbering: "Settlers log #4 of session" → "Settlers log #1" (consistent with heading, line 149) Co-Authored-By: Claude <noreply@anthropic.com> * fix(tsc): grok.ts pickModel — rename unused mode param to _mode (TS6133) grok-4.3 collapses thinking/fast into one model identifier; the Mode parameter is preserved for future cursor-agent updates but is currently unread, causing TS6133 under noUnusedLocals. Co-Authored-By: Claude <noreply@anthropic.com> --------- Co-authored-by: Claude <noreply@anthropic.com>

Copilot AI review requested due to automatic review settings May 13, 2026 06:34

AceHack enabled auto-merge (squash) May 13, 2026 06:34

Copilot started reviewing on behalf of AceHack May 13, 2026 06:35 View session

AceHack merged commit e2b39bd into main May 13, 2026
25 of 28 checks passed

AceHack deleted the fix-b0421-grok-ts-model-name-grok-4-20-thinking-deprecated-current-is-grok-4-3-2026-05-13 branch May 13, 2026 06:36

Copilot AI reviewed May 13, 2026

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AceHack mentioned this pull request May 13, 2026

shard(tick): 0645Z — settlers log #1 (Aaron named the format; Tales-from-the-Loop genre) — B-0421 fully closed + Vera autonomous fix + cross-agent-edit auth #2957

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fix(B-0421/1+2): grok-4-20-thinking deprecated → grok-4.3 (root cause + fix; closes B-0421)#2954

fix(B-0421/1+2): grok-4-20-thinking deprecated → grok-4.3 (root cause + fix; closes B-0421)#2954
AceHack merged 1 commit into
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fix-b0421-grok-ts-model-name-grok-4-20-thinking-deprecated-current-is-grok-4-3-2026-05-13

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		@@ -300,7 +300,19 @@ function buildFullPrompt(args: Args): PromptResult {
		}

		function pickModel(mode: Mode): string {

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AceHack commented May 13, 2026

Summary

What changed

B-0421 closure

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