diff --git a/CHANGELOG.md b/CHANGELOG.md
index 24e4cbb..3fc9aec 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,28 @@
 # Changelog
 
+## v0.21.0 — 2026-07-28 — the advisor, wired into your world
+
+**New: `statusline.sh check` — the advisor as an exit code.** The
+statusline never runs when you're away, which is exactly when expiring
+capacity needs a voice. Instead of a daemon (still no daemon, ever),
+`check` prints the plain-text advisor verdict and exits 0 calm / 1
+opportunity / 2 pressure / 3 unknown-or-stale — you wire it into tmux,
+cron, or CI. We provide the judgment; the host provides the plumbing.
+Model context for the scoped clauses comes from the last logged
+snapshot — the first consumer of v0.20's widened `model` field.
+
+**New: `statusline.sh session-summary` — one-line session
+retrospectives.** Designed as a `SessionEnd` hook (reads the hook JSON
+on stdin; falls back to the last logged session for manual runs):
+
+```
+session 8f3c02aa: 3h12m, 5h +34pts, 7d +4pts, claude-fable-5
+```
+
+Window deltas are positive-delta sums (the profile builder's rule), so
+a session that straddles a 5h reset still reports what it actually
+consumed. 334 tests (322 statusline + 12 installer).
+
 ## v0.20.0 — 2026-07-28 — the waste ledger: see what you paid for and didn't use
 
 **New: `statusline.sh report [--days N]` — the waste ledger.** The
diff --git a/README.md b/README.md
index 1216380..f3f534f 100644
--- a/README.md
+++ b/README.md
@@ -315,6 +315,47 @@ its reset, so usage from other devices after your last local render is
 invisible, and a week you never opened a session in never appears at
 all. The ledger reports what the log observed, nothing more.
 
+## Scripting: `check` and `session-summary`
+
+The statusline never runs when you're away — exactly when expiring
+capacity needs a voice. Instead of shipping a daemon, `check` exposes
+the advisor's judgment as an exit code; you provide the plumbing (tmux
+segment, cron, CI):
+
+```bash
+~/.claude/statusline.sh check
+# stdout: the plain advisor text, or "calm" / "unknown: ..."
+# exit 0 calm | 1 opportunity (+) | 2 pressure (!) | 3 unknown/stale
+```
+
+```bash
+# cron: nudge yourself when paid capacity is about to expire unused
+*/30 * * * * ~/.claude/statusline.sh check; [ $? -eq 1 ] && notify-send "$(~/.claude/statusline.sh check)"
+
+# tmux: advisor verdict in the status bar
+set -g status-right '#(~/.claude/statusline.sh check)'
+```
+
+`session-summary` is the same idea for session retrospectives — one
+line per session, built from the usage log, designed as a `SessionEnd`
+hook (it reads the hook JSON on stdin):
+
+```jsonc
+// settings.json
+"hooks": {
+  "SessionEnd": [{"hooks": [{"type": "command",
+    "command": "~/.claude/statusline.sh session-summary >> ~/.claude/statusline/session-summaries.log"}]}]
+}
+```
+
+```text
+session 8f3c02aa: 3h12m, 5h +34pts, 7d +4pts, claude-fable-5
+```
+
+Run it bare and it summarizes the last session in the log. Window
+deltas are positive-delta sums, so a session that straddles a 5h reset
+still reports what it actually consumed.
+
 <details><summary>OAuth and API behavior</summary>
 
 Quota, profile, and extra-usage requests use Claude Code's OAuth credentials
@@ -362,7 +403,7 @@ run. Setting only `CLAUDE_CACHE_DIR` keeps the legacy single-dir behavior.
 npm exec --yes bats -- t/
 ```
 
-327 tests across `t/statusline.bats` (315 statusline + integration) and
+334 tests across `t/statusline.bats` (322 statusline + integration) and
 `t/install.bats` (12 installer). CI runs on push and PR to `main`.
 
 ## Project Structure
diff --git a/docs/api/state-dir.md b/docs/api/state-dir.md
index 58a7536..da468bf 100644
--- a/docs/api/state-dir.md
+++ b/docs/api/state-dir.md
@@ -7,7 +7,7 @@ is the ONLY writer; everything here is safe to read concurrently.
 
 - Contract version: **1** (bump on any breaking layout/field change; this
   file is the changelog)
-- Synced with: statusline.sh v0.20.0
+- Synced with: statusline.sh v0.21.0
 - Permissions: the script runs under `umask 077` — files are owner-only.
   Caches hold account PII (email, uuid, org names).
 
diff --git a/docs/index.html b/docs/index.html
index c08c1b5..c6b7ffb 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -4,7 +4,7 @@
 <meta charset="utf-8">
 <meta name="viewport" content="width=device-width, initial-scale=1">
 <title>Claude Code Statusline — quota, context, cost. Live, in one bash file.</title>
-<meta name="description" content="Live 5h/7d quota with reset times, per-model weekly limits, context pressure, session cost, prompt-cache expiry detection, git activity, and a usage-advisor second row in your Claude Code prompt. One bash file, 327 tests, no daemon, no telemetry.">
+<meta name="description" content="Live 5h/7d quota with reset times, per-model weekly limits, context pressure, session cost, prompt-cache expiry detection, git activity, and a usage-advisor second row in your Claude Code prompt. One bash file, 334 tests, no daemon, no telemetry.">
 <style>
   :root {
     --bg: #0b0c0e;
@@ -130,7 +130,7 @@
     <h1>Claude Code Statusline</h1>
     <p class="sub">Quota, context, cost, model, and git — live in your Claude Code prompt.
     Know when the 5h window resets, how deep the weekly limit runs, and what this session costs, without leaving the terminal.</p>
-    <p class="facts">one bash file &middot; 327 tests &middot; deps: jq + curl &middot; no daemon &middot; no telemetry</p>
+    <p class="facts">one bash file &middot; 334 tests &middot; deps: jq + curl &middot; no daemon &middot; no telemetry</p>
 
     <div class="term">
       <div class="bar"><i></i><i></i><i></i><span>claude</span></div>
@@ -183,7 +183,7 @@ <h2>Built like it matters</h2>
       <p>Corporate mitm proxy or a local tracer: it builds a combined CA bundle from <code>NODE_EXTRA_CA_CERTS</code> automatically, so fetches survive where plain curl dies.</p></div>
     <div class="val"><h3>Documented wire contract</h3>
       <p>The <a href="https://github.com/thevibeworks/claude-code-statusline/blob/main/docs/api/oauth-usage.md">observed <code>/api/oauth/usage</code> schema</a> is versioned in-repo and re-synced against CLI captures, so parser changes check against ground truth.</p></div>
-    <div class="val"><h3>327 tests on one bash file</h3>
+    <div class="val"><h3>334 tests on one bash file</h3>
       <p>bats suite covering quota math, lock contention (20-contender single-winner), forecast pacing, ANSI rendering, and the installer. CI on every push.</p></div>
     <div class="val"><h3>Nothing running in the background</h3>
       <p>No daemon, no telemetry, no npm. It runs when Claude Code renders the prompt, reads stdin + one cached API call, prints a line, exits.</p></div>
diff --git a/llms.txt b/llms.txt
index 7be80c3..8dd6980 100644
--- a/llms.txt
+++ b/llms.txt
@@ -6,7 +6,7 @@
 > advisor second row that interprets the numbers (cap projections,
 > expiring-surplus and underuse advice, fleet relief) and a
 > `report` subcommand that ledgers what each closed window expired
-> unused. 327 bats tests, deps are jq + curl, no daemon, no telemetry.
+> unused. 334 bats tests, deps are jq + curl, no daemon, no telemetry.
 
 Key facts for agents:
 - Everything lives in `statusline.sh` (~3400 lines, plain bash). Install
@@ -33,7 +33,7 @@ Key facts for agents:
 
 - [statusline.sh](https://github.com/thevibeworks/claude-code-statusline/blob/main/statusline.sh): the entire product
 - [install.sh](https://github.com/thevibeworks/claude-code-statusline/blob/main/install.sh): installer (curl | bash entrypoint)
-- [t/statusline.bats](https://github.com/thevibeworks/claude-code-statusline/blob/main/t/statusline.bats): 315 statusline tests
+- [t/statusline.bats](https://github.com/thevibeworks/claude-code-statusline/blob/main/t/statusline.bats): 322 statusline tests
 - [t/install.bats](https://github.com/thevibeworks/claude-code-statusline/blob/main/t/install.bats): 12 installer tests
 
 ## Optional
diff --git a/statusline.sh b/statusline.sh
index 2665740..53e1e66 100755
--- a/statusline.sh
+++ b/statusline.sh
@@ -238,8 +238,8 @@ debug_log() {
 
 while [[ $# -gt 0 ]]; do
     case $1 in
-    report)
-        subcommand="report"
+    report | check | session-summary)
+        subcommand="$1"
         shift
         ;;
     --days)
@@ -2124,6 +2124,97 @@ run_usage_report() {
     return 0
 }
 
+# `statusline.sh check` — the advisor as an exit code, for tmux segments,
+# cron notifiers, and scripts (`check || notify`). Prints the plain-text
+# advisor verdict (or "calm"/"unknown: ...") and exits:
+#   0 calm    1 opportunity (+)    2 pressure (!)    3 unknown/stale
+# We provide the judgment; the host provides the plumbing — no daemon.
+# Model context comes from the last logged snapshot, so scoped clauses
+# know which model this account was last running.
+run_check() {
+    local uc="$CLAUDE_ACCOUNT_DIR/usage.cache"
+    if [ ! -f "$uc" ]; then
+        echo "unknown: no usage.cache under $CLAUDE_ACCOUNT_DIR"
+        return 3
+    fi
+    local fetched age
+    fetched=$(jq -r '.fetched_at // 0' "$uc" 2>/dev/null)
+    age=$(( $(date +%s) - ${fetched:-0} ))
+    if [ "$age" -gt 3600 ] 2>/dev/null; then
+        # The state-dir contract's staleness rule: >1h old means no active
+        # session feeds this account — the numbers describe the past.
+        echo "unknown: usage.cache ${age}s stale (no active session feeding this account)"
+        return 3
+    fi
+    local last_model=""
+    [ -f "$CLAUDE_ACCOUNT_DIR/usage.jsonl" ] && \
+        last_model=$(tail -1 "$CLAUDE_ACCOUNT_DIR/usage.jsonl" 2>/dev/null | jq -r '.model // empty' 2>/dev/null)
+    local line plain
+    line=$(build_advisor_line "$(cat "$uc")" auto "$last_model")
+    if [ -z "$line" ]; then
+        echo "calm"
+        return 0
+    fi
+    plain=$(printf '%b' "$line" | sed 's/\x1b\[[0-9;]*m//g')
+    printf '%s\n' "$plain"
+    case "$plain" in
+    "! "*) return 2 ;;
+    "+ "*) return 1 ;;
+    esac
+    return 0
+}
+
+# `statusline.sh session-summary` — one-line session retrospective, designed
+# as a SessionEnd hook (pipe the hook JSON in; only session_id is read).
+# Falls back to the last session in the log for manual runs. Window deltas
+# are positive-delta sums (resets ignored), the profile builder's rule, so
+# a session that straddles a 5h reset still reports what it consumed.
+run_session_summary() {
+    local sid=""
+    [ ! -t 0 ] && sid=$(cat 2>/dev/null | jq -r '.session_id // empty' 2>/dev/null)
+    local jsonl="$CLAUDE_ACCOUNT_DIR/usage.jsonl"
+    if [ -z "$sid" ] && [ -f "$jsonl" ]; then
+        sid=$(jq -r 'select((.type // "") == "usage") | .session_id // empty' "$jsonl" 2>/dev/null | tail -1)
+    fi
+    if [ -z "$sid" ]; then
+        echo "session-summary: no session id (pipe hook JSON, or log some usage first)"
+        return 1
+    fi
+    if [ ! -f "$jsonl" ] && [ ! -f "${jsonl}.1" ]; then
+        echo "session-summary: no usage log at $jsonl"
+        return 1
+    fi
+    local out
+    out=$( { cat "${jsonl}.1" 2>/dev/null; cat "$jsonl" 2>/dev/null; } | jq -r --arg s "$sid" '
+            select((.type // "") == "usage" and (.session_id // "") == $s)
+            | [.timestamp, (.five_hour.utilization // ""),
+               (.seven_day.utilization // ""), (.model // "")]
+            | @tsv' 2>/dev/null \
+        | sort -n | awk -F'\t' -v sid="${sid:0:8}" '
+        {
+            n++
+            if (first == "") first = $1
+            last = $1
+            if ($2 != "") { if (pf != "" && $2 > pf) df += $2 - pf; pf = $2 }
+            if ($3 != "") { if (ps != "" && $3 > ps) ds += $3 - ps; ps = $3 }
+            if ($4 != "") model = $4
+        }
+        END {
+            if (n == 0) exit 0
+            secs = last - first
+            h = int(secs / 3600); m = int((secs % 3600) / 60)
+            dur = (h > 0 ? h "h" m "m" : m "m")
+            printf "session %s: %s, 5h +%.0fpts, 7d +%.0fpts%s\n", \
+                sid, dur, df, ds, (model != "" ? ", " model : "")
+        }')
+    if [ -z "$out" ]; then
+        echo "session-summary: no samples for session ${sid:0:8}"
+        return 1
+    fi
+    printf '%s\n' "$out"
+    return 0
+}
+
 # Generalized change flash: signed delta between the current value and the
 # last value THIS session rendered, held for QUOTA_BUMP_NOTICE_SECS after the
 # change so the refresh right after a jump still shows it. One JSON state
@@ -3085,6 +3176,8 @@ build_1m_tag() {
 if [ -n "$subcommand" ]; then
     case "$subcommand" in
     report) run_usage_report "${report_days:-28}"; exit $? ;;
+    check) run_check; exit $? ;;
+    session-summary) run_session_summary; exit $? ;;
     esac
     exit 0
 fi
diff --git a/t/helpers.bash b/t/helpers.bash
index 45e9ec9..4e35b7a 100644
--- a/t/helpers.bash
+++ b/t/helpers.bash
@@ -64,7 +64,7 @@ debug_log() {
 # Source individual functions by extracting them from statusline.sh.
 # This is deliberate: we test the actual production code, not copies.
 eval "$(awk '
-    /^(abbreviate_model_id|get_runtime_model|format_reset_relative|format_reset_absolute|get_reset_seconds|format_duration|should_show_extra|get_cache_health|infer_cache_ttl_class|build_cache_indicator|get_usage_color|get_seven_day_color|seven_day_elapsed|seven_day_pace|weekend_secs_ahead|get_adaptive_ttl|curl_ca_bundle|acquire_lock|reap_stale_lock|fetch_usage_for_session|merge_stdin_rate_limits|rotate_usage_log|build_seven_day_profile|seven_day_forecast|premium_band_level|abbrev_effort|effort_color|_epoch_from_ts|_fmt_epoch|render_bar|format_money_minor|oauth_token_expired|refresh_oauth_credentials_file|is_default_1m_family|get_context_limit|is_1m_model|rotate_debug_log|build_display_path|delta_flash|delta_flash_part|quota_bump_notice|record_fetch_error|fetch_error_remaining|fetch_error_badge|model_scope_abbrev|build_scoped_quota_display|build_usage_display|build_extra_usage_display|build_user_info|get_user_tier|build_advisor_line|build_advisor_fleet_hint|_seven_day_walk|forecast_pct_per_window|log_usage_snapshot|detect_session_boundary|run_usage_report)\(\)/ { capture=1 }
+    /^(abbreviate_model_id|get_runtime_model|format_reset_relative|format_reset_absolute|get_reset_seconds|format_duration|should_show_extra|get_cache_health|infer_cache_ttl_class|build_cache_indicator|get_usage_color|get_seven_day_color|seven_day_elapsed|seven_day_pace|weekend_secs_ahead|get_adaptive_ttl|curl_ca_bundle|acquire_lock|reap_stale_lock|fetch_usage_for_session|merge_stdin_rate_limits|rotate_usage_log|build_seven_day_profile|seven_day_forecast|premium_band_level|abbrev_effort|effort_color|_epoch_from_ts|_fmt_epoch|render_bar|format_money_minor|oauth_token_expired|refresh_oauth_credentials_file|is_default_1m_family|get_context_limit|is_1m_model|rotate_debug_log|build_display_path|delta_flash|delta_flash_part|quota_bump_notice|record_fetch_error|fetch_error_remaining|fetch_error_badge|model_scope_abbrev|build_scoped_quota_display|build_usage_display|build_extra_usage_display|build_user_info|get_user_tier|build_advisor_line|build_advisor_fleet_hint|_seven_day_walk|forecast_pct_per_window|log_usage_snapshot|detect_session_boundary|run_usage_report|run_check|run_session_summary)\(\)/ { capture=1 }
     capture { print }
     capture && /^}$/ { capture=0 }
 ' "$SCRIPT_DIR/statusline.sh")"
diff --git a/t/statusline.bats b/t/statusline.bats
index b375aef..22e9188 100644
--- a/t/statusline.bats
+++ b/t/statusline.bats
@@ -762,6 +762,109 @@ _write_ledger_fixture() { # dir
     rm -rf "$tmpdir"
 }
 
+# --- check + session-summary subcommands -----------------------------------
+
+@test "run_check: calm cache prints calm and exits 0" {
+    tmpdir=$(mktemp -d)
+    CLAUDE_ACCOUNT_DIR="$tmpdir"
+    reset_5h=$(date -u -d '+45 minutes' '+%Y-%m-%dT%H:%M:%SZ')
+    reset_7d=$(date -u -d '+5 days' '+%Y-%m-%dT%H:%M:%SZ')
+    printf '{"fetched_at":%s,"five_hour":{"utilization":20,"resets_at":"%s"},"seven_day":{"utilization":20,"resets_at":"%s"}}' \
+        "$(date +%s)" "$reset_5h" "$reset_7d" > "$tmpdir/usage.cache"
+    run run_check
+    [ "$status" -eq 0 ]
+    [ "$output" = "calm" ]
+    rm -rf "$tmpdir"
+}
+
+@test "run_check: pressure exits 2 with the plain advisor text" {
+    tmpdir=$(mktemp -d)
+    CLAUDE_ACCOUNT_DIR="$tmpdir"
+    # 85% only 2h into the window: hot pace, caps before reset (pressure)
+    reset_5h=$(date -u -d '+3 hours' '+%Y-%m-%dT%H:%M:%SZ')
+    printf '{"fetched_at":%s,"five_hour":{"utilization":85,"resets_at":"%s"},"seven_day":{"utilization":10}}' \
+        "$(date +%s)" "$reset_5h" > "$tmpdir/usage.cache"
+    run run_check
+    [ "$status" -eq 2 ]
+    [[ "$output" == "! 5h caps"* ]]
+    rm -rf "$tmpdir"
+}
+
+@test "run_check: expiring surplus exits 1 (opportunity)" {
+    tmpdir=$(mktemp -d)
+    CLAUDE_ACCOUNT_DIR="$tmpdir"
+    # 5h on pace (40% at 60% elapsed), 7d resets in 10h with 56% unused
+    reset_5h=$(date -u -d '+2 hours' '+%Y-%m-%dT%H:%M:%SZ')
+    reset_7d=$(date -u -d '+10 hours' '+%Y-%m-%dT%H:%M:%SZ')
+    printf '{"fetched_at":%s,"five_hour":{"utilization":40,"resets_at":"%s"},"seven_day":{"utilization":44,"resets_at":"%s"}}' \
+        "$(date +%s)" "$reset_5h" "$reset_7d" > "$tmpdir/usage.cache"
+    run run_check
+    [ "$status" -eq 1 ]
+    [[ "$output" == "+ 7d resets"* ]]
+    rm -rf "$tmpdir"
+}
+
+@test "run_check: missing or stale cache exits 3" {
+    tmpdir=$(mktemp -d)
+    CLAUDE_ACCOUNT_DIR="$tmpdir"
+    run run_check
+    [ "$status" -eq 3 ]
+    [[ "$output" == "unknown: no usage.cache"* ]]
+    printf '{"fetched_at":%s,"five_hour":{"utilization":85}}' "$(( $(date +%s) - 7200 ))" > "$tmpdir/usage.cache"
+    run run_check
+    [ "$status" -eq 3 ]
+    [[ "$output" == *"stale"* ]]
+    rm -rf "$tmpdir"
+}
+
+_write_session_fixture() { # dir
+    local dir="$1" now
+    now=$(date +%s)
+    : > "$dir/usage.jsonl"
+    printf '{"type":"usage","session_id":"S1","timestamp":%s,"five_hour":{"utilization":10},"seven_day":{"utilization":5}}\n' "$(( now - 4000 ))" >> "$dir/usage.jsonl"
+    printf '{"type":"usage","session_id":"S1","timestamp":%s,"five_hour":{"utilization":40},"seven_day":{"utilization":7}}\n' "$(( now - 2000 ))" >> "$dir/usage.jsonl"
+    printf '{"type":"usage","session_id":"S1","timestamp":%s,"five_hour":{"utilization":70},"seven_day":{"utilization":9},"model":"claude-fable-5"}\n' "$(( now - 300 ))" >> "$dir/usage.jsonl"
+}
+
+@test "run_session_summary: summarizes the piped hook session" {
+    tmpdir=$(mktemp -d)
+    CLAUDE_ACCOUNT_DIR="$tmpdir"
+    _write_session_fixture "$tmpdir"
+    out=$(printf '{"session_id":"S1"}' | run_session_summary)
+    # 3700s span, +60 five-points, +4 seven-points, model from the last sample
+    [ "$out" = "session S1: 1h1m, 5h +60pts, 7d +4pts, claude-fable-5" ]
+    rm -rf "$tmpdir"
+}
+
+@test "run_session_summary: falls back to the last logged session; unknown exits 1" {
+    tmpdir=$(mktemp -d)
+    CLAUDE_ACCOUNT_DIR="$tmpdir"
+    _write_session_fixture "$tmpdir"
+    out=$(run_session_summary < /dev/null)
+    [[ "$out" == "session S1:"* ]]
+    if printf '{"session_id":"nope"}' | run_session_summary > /dev/null; then
+        false
+    fi
+    rm -rf "$tmpdir"
+}
+
+@test "integration: check and session-summary run end-to-end" {
+    tmpdir=$(mktemp -d)
+    mkdir -p "$tmpdir/data"
+    reset_5h=$(date -u -d '+45 minutes' '+%Y-%m-%dT%H:%M:%SZ')
+    reset_7d=$(date -u -d '+5 days' '+%Y-%m-%dT%H:%M:%SZ')
+    printf '{"fetched_at":%s,"five_hour":{"utilization":20,"resets_at":"%s"},"seven_day":{"utilization":20,"resets_at":"%s"}}' \
+        "$(date +%s)" "$reset_5h" "$reset_7d" > "$tmpdir/data/usage.cache"
+    _write_session_fixture "$tmpdir/data"
+    run env HOME="$tmpdir" CLAUDE_DATA_DIR="$tmpdir/data" bash "$SCRIPT_DIR/statusline.sh" check
+    [ "$status" -eq 0 ]
+    [ "$output" = "calm" ]
+    run bash -c "printf '{\"session_id\":\"S1\"}' | env HOME='$tmpdir' CLAUDE_DATA_DIR='$tmpdir/data' bash '$SCRIPT_DIR/statusline.sh' session-summary"
+    [ "$status" -eq 0 ]
+    [[ "$output" == "session S1:"* ]]
+    rm -rf "$tmpdir"
+}
+
 _write_profile_cache() { # $1=dir $2=days_history $3=rate_all_days $4=recent24
     cat > "$1/forecast.cache" <<EOF
 {"computed_at":$(date +%s),"days_history":$2,"recent_24h":$4,"recent_48h":0,