kohen: fallback for Claude Code when the gate is down

Every Claude Code session on the dev VM goes through bikoret.ch; when
the pod is not ready the session cannot reach Anthropic (2026-10-15:
Doorpost drift → 503 → the transmitter locked out, recovered by hand).
An `env` entry in ~/.claude/settings.json overrides the shell
environment (verified), so `env -u … claude` is not a recovery while
the gate is armed there.

- scripts/claude-direct: start straight to Anthropic via a --settings
  JSON on the command line, which outranks every settings file.
- scripts/claude-bikoret: probe the gate first; if it does not answer,
  say so and exec claude-direct (BIKORET_STRICT=1 refuses instead).
- scripts/bikoret-settings on|off|status: arm/disarm the gate for every
  launcher; `on` writes the key (kohen only), `off` is the recovery.
- KOHEN.md: the fallback and the order of recovery.

Tested 2026-10-15: dead gate armed in settings → plain claude hangs,
claude-direct answers; probe at a dead host → fallback + answer; live
gate → answer with the fringe.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

KOHEN.md

@@ -620,6 +620,34 @@ Each upstream call spends one `api_calls_external` of the day's manna
 the bedikah by hand still runs. Streaming is refused (422). A non-200
 from the model passes through as it came. Tamid §1.1 has the contract.
 
+**Fallback — when the gate is down, Claude Code here is down with it.**
+Every request of a session behind the gate goes to bikoret.ch; if the pod
+is not ready (503: stale manna at the day boundary, a Doorpost drift, a
+hung rollout) the session cannot reach Anthropic at all. Note that an
+`env` entry in `~/.claude/settings.json` OVERRIDES the shell environment
+(verified 2026-10-15): `env -u ANTHROPIC_BASE_URL … claude` does nothing
+while the gate is armed there. Three tools, all in `scripts/` (install to
+`~/.local/bin`), none of which holds a key:
+
+```bash
+claude-direct             # start Claude Code straight to Anthropic, whatever
+                          # settings.json says (a --settings JSON on the command
+                          # line outranks every settings file); OAuth as usual
+claude-bikoret            # start behind the gate; probes the gate first and, if
+                          # it does not answer, says so and starts claude-direct.
+                          # BIKORET_STRICT=1 claude-bikoret refuses instead.
+bikoret-settings on|off|status
+                          # arm / disarm the gate for EVERY launcher (desktop,
+                          # background jobs, plain `claude`) via settings.json.
+                          # `on` writes the courtyard key there — the kohen runs
+                          # it, not the builder; `off` is the recovery.
+```
+
+Order of recovery: `claude-direct` (always works), then `bikoret-settings
+off` if background sessions must also recover, then fix the pod
+(`curl -s https://bikoret.ch/kodesh/health` names the failed check), then
+`bikoret-settings on` and `claude-bikoret` again.
+
 ### The second scroll — *Mishneh haTorah*
 
 `/kodesh/health` carries `mesorah_hash` beside `l1_hash`: the mesorah

scripts/bikoret-settings

@@ -0,0 +1,33 @@
+#!/usr/bin/env python3
+# Arm or disarm the gate in Claude Code's settings.json (the `env` block is
+# applied to EVERY launcher — desktop, background jobs, the plain `claude`).
+#
+#   bikoret-settings on      put ANTHROPIC_BASE_URL + ANTHROPIC_CUSTOM_HEADERS in
+#   bikoret-settings off     remove them (the fallback when the gate is down)
+#   bikoret-settings status  say which
+#
+# `on` writes the courtyard key into a config file, so the transmitter runs it:
+# the builder is not allowed to write a credential there. `off` writes none.
+import json, os, sys
+p = os.path.expanduser("~/.claude/settings.json")
+KEYS = ("ANTHROPIC_BASE_URL", "ANTHROPIC_CUSTOM_HEADERS")
+mode = sys.argv[1] if len(sys.argv) > 1 else "status"
+d = json.load(open(p))
+env = d.get("env", {})
+if mode == "on":
+    k = [l.split()[1] for l in open(os.path.expanduser("~/.config/shorashim/api_keys")) if l.startswith("courtyard")][0]
+    env.update({"ANTHROPIC_BASE_URL": "https://bikoret.ch/gate/anthropic",
+                "ANTHROPIC_CUSTOM_HEADERS": "X-Bikoret-Key: " + k})
+    d["env"] = env
+elif mode == "off":
+    for key in KEYS:
+        env.pop(key, None)
+    if env: d["env"] = env
+    else: d.pop("env", None)
+elif mode != "status":
+    sys.exit("usage: bikoret-settings on|off|status")
+if mode in ("on", "off"):
+    json.dump(d, open(p, "w"), indent=2)
+    os.chmod(p, 0o600)
+armed = all(k in d.get("env", {}) for k in KEYS)
+print("gate in settings.json:", "ARMED (every launcher goes through bikoret.ch)" if armed else "off (direct to Anthropic)")

scripts/claude-bikoret

@@ -0,0 +1,27 @@
+#!/bin/bash
+# Start Claude Code behind the gate (KOHEN "Claude Code behind the gate").
+# The courtyard key is read from the keys file at launch and never written anywhere else.
+#
+# Fallback (2026-10-15): before launching, probe the gate. If bikoret.ch or
+# the pod is down, say so and start DIRECT to Anthropic instead
+# (claude-direct), unless BIKORET_STRICT=1 — then refuse, so a session that
+# must be examined is never silently unexamined.
+GATE="https://bikoret.ch/gate/anthropic"
+code=$(curl -sS -m 6 -o /dev/null -w '%{http_code}' -X POST "$GATE/v1/messages" \
+       -H 'content-type: application/json' -d '{}' 2>/dev/null)
+case "$code" in
+  401|400|422) ;;   # the gate answered: it is up (it refuses an unkeyed/empty request)
+  *)
+    echo "bikoret gate not answering (HTTP ${code:-000}) — see: curl -s https://bikoret.ch/kodesh/health" >&2
+    if [ "${BIKORET_STRICT:-0}" = "1" ]; then
+      echo "BIKORET_STRICT=1: refusing to start unexamined" >&2; exit 1
+    fi
+    echo "starting DIRECT to Anthropic (claude-direct); re-run claude-bikoret when the gate is back" >&2
+    exec "$HOME/.local/bin/claude-direct" "$@"
+    ;;
+esac
+KEY=$(awk '$1=="courtyard"{print $2}' "$HOME/.config/shorashim/api_keys")
+[ -n "$KEY" ] || { echo "no courtyard key in ~/.config/shorashim/api_keys" >&2; exit 1; }
+export ANTHROPIC_BASE_URL="$GATE"
+export ANTHROPIC_CUSTOM_HEADERS="X-Bikoret-Key: $KEY"
+exec claude "$@"

scripts/claude-direct

@@ -0,0 +1,12 @@
+#!/bin/bash
+# Start Claude Code DIRECT to Anthropic, bypassing the Bikoret gate — the
+# fallback for when bikoret.ch / the pod is down (KOHEN "Claude Code behind
+# the gate — fallback").
+#
+# Why --settings and not `env -u`: an `env` entry in ~/.claude/settings.json
+# overrides the shell environment (verified 2026-10-15), so unsetting the
+# variables in the shell does nothing while the gate is armed there. A
+# `--settings` JSON on the command line outranks every settings file, so it
+# wins without touching settings.json. OAuth login is used as normal.
+unset ANTHROPIC_BASE_URL ANTHROPIC_CUSTOM_HEADERS
+exec claude --settings '{"env":{"ANTHROPIC_BASE_URL":"https://api.anthropic.com","ANTHROPIC_CUSTOM_HEADERS":""}}' "$@"