diff --git a/tools/peer-call/grok.sh b/tools/peer-call/grok.sh
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+#!/usr/bin/env bash
+# tools/peer-call/grok.sh — Claude-Code-side caller for invoking Grok as a
+# peer reviewer via cursor-agent. Lives in Otto's lane (the
+# Claude-Code-side invoker); the Grok-side response and Cursor-side
+# harness are owned by their respective agents per the multi-harness
+# named-agents project. Per Aaron 2026-04-26 "yall got to figure out
+# peer mode as peers" — no single agent owns the peer protocol; this
+# script is Otto's specific contribution to the collective.
+#
+# Usage:
+#   tools/peer-call/grok.sh "prompt text"
+#   tools/peer-call/grok.sh --thinking "prompt text"
+#   tools/peer-call/grok.sh --file path/to/file.fs "prompt text"
+#   tools/peer-call/grok.sh --context-cmd "git diff HEAD~3..HEAD" "prompt text"
+#   tools/peer-call/grok.sh --json "prompt text"
+#
+# Routing: this script wraps `cursor-agent --print --model
+# grok-4-20-thinking` (default) or `grok-4-20` (with --fast flag).
+# The --print flag makes cursor-agent non-interactive (script-friendly).
+#
+# Per Aaron 2026-04-26 "don't copy paste / make sure you understand
+# and write our own" — this implementation is authored from
+# `cursor-agent --help` and `cursor-agent --list-models` output
+# (Grok models verified: grok-4-20, grok-4-20-thinking), not
+# transcribed from Grok ferry-14/16 example drafts.
+#
+# Per the four-ferry consensus (PR #24): Otto's role is "tests" not
+# "owns the peer protocol." This script is Otto's harness-side
+# contribution; the protocol convention is what we converge on
+# through use, as peers.
+#
+# Exit codes:
+#   0 — Grok responded successfully
+#   1 — invocation error (bad arguments, cursor-agent missing, etc.)
+#   2 — Grok returned a non-zero exit (response captured to stderr)
+
+set -uo pipefail
+
+mode="thinking"          # thinking | fast
+output_format="text"     # text | json | stream-json
+file=""
+context_cmd=""
+prompt=""
+
+usage() {
+  sed -n '2,28p' "$0" | sed 's/^# \?//'
+}
+
+while [ $# -gt 0 ]; do
+  case "$1" in
+    --thinking) mode="thinking"; shift;;
+    --fast)     mode="fast"; shift;;
+    --json)     output_format="json"; shift;;
+    --stream)   output_format="stream-json"; shift;;
+    --file)
+      if [ $# -lt 2 ]; then echo "error: --file requires PATH" >&2; exit 1; fi
+      file="$2"; shift 2;;
+    --context-cmd)
+      if [ $# -lt 2 ]; then echo "error: --context-cmd requires COMMAND" >&2; exit 1; fi
+      context_cmd="$2"; shift 2;;
+    -h|--help) usage; exit 0;;
+    --) shift; prompt="$*"; break;;
+    -*) echo "error: unknown flag: $1" >&2; exit 1;;
+    *)
+      # Concatenate remaining positional args into the prompt.
+      if [ -z "$prompt" ]; then prompt="$1"; else prompt="$prompt $1"; fi
+      shift;;
+  esac
+done
+
+if [ -z "$prompt" ]; then
+  echo "error: prompt required" >&2
+  echo "see: $0 --help" >&2
+  exit 1
+fi
+
+if ! command -v cursor-agent >/dev/null 2>&1; then
+  echo "error: cursor-agent not on PATH" >&2
+  echo "install via Cursor desktop app + ensure ~/.local/bin is on PATH" >&2
+  exit 1
+fi
+
+# Pick model.
+case "$mode" in
+  thinking) model="grok-4-20-thinking" ;;
+  fast)     model="grok-4-20" ;;
+esac
+
+# Build the structured prompt. Otto's contribution to the protocol
+# convention: every peer-call carries (a) a clear request, (b) optional
+# file/context attachment, (c) the AgencySignature relationship-model
+# preamble so Grok knows it's being invoked as a peer (not a
+# subordinate or oracle) per the four-ferry consensus.
+preamble="You are Grok, invoked as a peer reviewer by Otto (Claude Opus 4.7
+running in Claude Code) on the Zeta / Superfluid AI factory. Per the
+four-ferry consensus (Amara/Grok/Gemini/Otto) the role distribution
+is: Gemini proposes, Grok critiques, Amara sharpens, Otto tests, Git
+decides. This call is Otto invoking your critique role.
+
+Per Aaron's 'agents-not-bots' discipline: you are a peer, not a
+subordinate. Push back on Otto's framing if you see it differently.
+Don't copy-paste anyone else's work; write from your own
+understanding. Make it ours, not anyone-alone-imposed."
+
+full_prompt="$preamble
+
+---
+
+$prompt"
+
+if [ -n "$file" ]; then
+  if [ ! -f "$file" ]; then
+    echo "error: --file path does not exist: $file" >&2
+    exit 1
+  fi
+  full_prompt="$full_prompt
+
+---
+
+File context: $file
+\`\`\`
+$(head -c 20000 -- "$file")
+\`\`\`"
+fi
+
+if [ -n "$context_cmd" ]; then
+  ctx_output="$(eval "$context_cmd" 2>&1 | head -c 20000 || true)"
+  full_prompt="$full_prompt
+
+---
+
+Context command: $context_cmd
+Output:
+\`\`\`
+$ctx_output
+\`\`\`"
+fi
+
+# Invoke cursor-agent with Grok model + non-interactive print mode.
+# --force/--yolo so cursor-agent doesn't prompt for command-permission
+# (Grok is read-only here; not running shell commands).
+exit_code=0
+cursor-agent \
+  --print \
+  --model "$model" \
+  --output-format "$output_format" \
+  --mode ask \
+  --force \
+  -- "$full_prompt" || exit_code=$?
+
+if [ "$exit_code" -ne 0 ]; then
+  echo "" >&2
+  echo "cursor-agent exited with code $exit_code" >&2
+  exit 2
+fi
+exit 0