diff --git a/README.md b/README.md
index 6bc7f70..09cdde0 100644
--- a/README.md
+++ b/README.md
@@ -39,7 +39,10 @@ Once restarted, you'll see a confirmation message and notifications will appear
 
 - [Warp terminal](https://warp.dev) (macOS, Linux, or Windows)
 - [Claude Code](https://docs.anthropic.com/en/docs/claude-code) CLI
-- `jq` for JSON parsing (install via `brew install jq` or your package manager)
+- `jq` for JSON parsing — install via your package manager:
+  - macOS: `brew install jq`
+  - Linux: `sudo apt install jq` (Debian/Ubuntu) or `sudo dnf install jq` (Fedora)
+  - Windows: `scoop install jq` or `choco install jq`
 
 ## How It Works
 
diff --git a/plugins/warp/scripts/build-payload.sh b/plugins/warp/scripts/build-payload.sh
index 9ad610e..b2414e1 100644
--- a/plugins/warp/scripts/build-payload.sh
+++ b/plugins/warp/scripts/build-payload.sh
@@ -13,6 +13,14 @@
 # The function extracts common fields (session_id, cwd, project) from the
 # hook's stdin JSON (passed as $1), then merges any extra jq args you pass.
 
+# Bail out early if jq is not available — every path through this script
+# requires it, and a missing jq produces confusing "command not found" errors
+# in hook output that Claude Code surfaces as hook errors.
+if ! command -v jq &>/dev/null; then
+    echo "jq is required but not found. Install it via your package manager." >&2
+    exit 1
+fi
+
 # The current protocol version this plugin knows how to produce.
 PLUGIN_CURRENT_PROTOCOL_VERSION=1
 
diff --git a/plugins/warp/scripts/emit-terminal-sequence.sh b/plugins/warp/scripts/emit-terminal-sequence.sh
index b6a83b9..604a2d7 100644
--- a/plugins/warp/scripts/emit-terminal-sequence.sh
+++ b/plugins/warp/scripts/emit-terminal-sequence.sh
@@ -8,9 +8,10 @@
 # write to /dev/tty instead.
 #
 # Decision tree:
-#   1. CLAUDE_CODE_VERSION known, >= 2.1.141 → emit terminalSequence JSON
-#   2. CLAUDE_CODE_VERSION known, <  2.1.141 → write /dev/tty; give up if missing
-#   3. CLAUDE_CODE_VERSION unknown            → try /dev/tty, fall back to JSON
+#   1. Windows (MSYS/MINGW/Cygwin)                 → always use terminalSequence JSON
+#   2. CLAUDE_CODE_VERSION known, >= 2.1.141       → emit terminalSequence JSON
+#   3. CLAUDE_CODE_VERSION known, <  2.1.141       → write /dev/tty; give up if missing
+#   4. CLAUDE_CODE_VERSION unknown (non-Windows)    → try /dev/tty, fall back to JSON
 #
 # Usage:
 #   source "$SCRIPT_DIR/emit-terminal-sequence.sh"
@@ -24,6 +25,13 @@
 # The first Claude Code version that supports the terminalSequence output field.
 TERMINAL_SEQUENCE_MIN_VERSION="2.1.141"
 
+# Returns 0 (true) if running under Windows (MSYS, MINGW, or Cygwin).
+_is_windows() {
+    local kernel
+    kernel="$(uname -s 2>/dev/null)"
+    [[ "$kernel" == MINGW* || "$kernel" == MSYS* || "$kernel" == CYGWIN* ]]
+}
+
 # Compare two dotted version strings (e.g. "2.1.141" >= "2.1.141").
 # Returns 0 (true) if $1 >= $2, 1 (false) otherwise.
 _version_at_least() {
@@ -59,6 +67,12 @@ emit_terminal_sequence() {
     local seq="$1"
     [ -z "$seq" ] && return 0
 
+    # Windows has no /dev/tty — always use the JSON terminalSequence path.
+    if _is_windows; then
+        jq -nc --arg seq "$seq" '{terminalSequence: $seq}'
+        return 0
+    fi
+
     # Classify the running Claude Code version, if we can.
     local raw="${CLAUDE_CODE_VERSION:-}"
     local ver=""
diff --git a/plugins/warp/tests/test-hooks.sh b/plugins/warp/tests/test-hooks.sh
index 754bdd0..0ce89b7 100755
--- a/plugins/warp/tests/test-hooks.sh
+++ b/plugins/warp/tests/test-hooks.sh
@@ -260,6 +260,58 @@ OUTPUT=$(emit_terminal_sequence "test-seq")
 assert_json_field "new CC outputs terminalSequence" "$OUTPUT" ".terminalSequence" "test-seq"
 unset CLAUDE_CODE_VERSION
 
+echo ""
+echo "--- _is_windows ---"
+
+# _is_windows should return 0 on Windows (MSYS/MINGW/Cygwin), 1 otherwise.
+# The test result depends on the host OS, so we assert against uname.
+_kernel="$(uname -s 2>/dev/null)"
+_is_windows
+if [[ "$_kernel" == MINGW* || "$_kernel" == MSYS* || "$_kernel" == CYGWIN* ]]; then
+    assert_eq "Windows kernel returns true" "0" "$?"
+else
+    assert_eq "non-Windows kernel returns false" "1" "$?"
+fi
+
+echo ""
+echo "--- Windows: emit_terminal_sequence skips /dev/tty ---"
+
+# On non-Windows we can't fully test the Windows branch, but we can verify
+# that when _is_windows is true (mocked), the function outputs terminalSequence JSON
+# instead of trying /dev/tty. We mock _is_windows by temporarily overriding it.
+_is_windows_orig="$(declare -f _is_windows)"
+_is_windows_mock() { return 0; }
+# Replace the function
+eval "_is_windows() { return 0; }"
+
+unset CLAUDE_CODE_VERSION
+OUTPUT=$(emit_terminal_sequence "win-test-seq" 2>&1)
+assert_json_field "Windows outputs terminalSequence JSON" "$OUTPUT" ".terminalSequence" "win-test-seq"
+
+# Also test with old CC version on Windows — should still use JSON, not /dev/tty
+export CLAUDE_CODE_VERSION="2.1.100"
+OUTPUT=$(emit_terminal_sequence "win-old-cc-seq" 2>&1)
+assert_json_field "Windows + old CC outputs terminalSequence JSON" "$OUTPUT" ".terminalSequence" "win-old-cc-seq"
+unset CLAUDE_CODE_VERSION
+
+# Restore original _is_windows
+eval "$_is_windows_orig"
+
+echo ""
+echo "--- jq guard in build-payload.sh ---"
+
+# When jq is missing, sourcing build-payload.sh should exit 1 with a clear message.
+# We set PATH to only include the bash binary's directory (no jq).
+SCRIPT_DIR_TEST="$(cd "$(dirname "${BASH_SOURCE[0]}")/../scripts" && pwd)"
+_minimal_path="$(dirname "$(command -v bash)")"
+OUTPUT=$(PATH="$_minimal_path" bash -c "source '$SCRIPT_DIR_TEST/build-payload.sh'" 2>&1)
+_rc=$?
+if [ "$_rc" -ne 0 ] && echo "$OUTPUT" | grep -qi "jq"; then
+    assert_eq "build-payload.sh fails gracefully when jq missing" "0" "0"
+else
+    assert_eq "build-payload.sh fails gracefully when jq missing" "1" "0 (exit=$_rc, output=$OUTPUT)"
+fi
+
 # --- Routing tests ---
 # These test the hook scripts as subprocesses to verify routing behavior.
 # We override /dev/tty writes since they'd fail in CI.