diff --git a/internal/adaptercfg/adaptercfg.go b/internal/adaptercfg/adaptercfg.go
index c8f0b9c..c8d680a 100644
--- a/internal/adaptercfg/adaptercfg.go
+++ b/internal/adaptercfg/adaptercfg.go
@@ -52,11 +52,22 @@ func FromResolved(rs *state.Resolved, channel, tokenRef string) (Config, error)
 	return Config{
 		Campaign: rs.Campaign,
 		Channel:  channel,
-		ChatID:   ch.ChatID,
+		ChatID:   BotAPIChatID(ch.ChatID),
 		TokenRef: tokenRef,
 	}, nil
 }
 
+// BotAPIChatID converts a channel id as the provisioner records it (the
+// MTProto channel id, positive) into the form the Bot API addresses it by
+// (-100 followed by the id). An id that is already negative is in Bot API
+// form and is returned unchanged.
+func BotAPIChatID(id int64) int64 {
+	if id > 0 {
+		return -1000000000000 - id
+	}
+	return id
+}
+
 // EnvFile is the non-secret configuration an adapter process is started with.
 // The token is named, not emitted: the runtime injects it from OpenBao.
 func (c Config) EnvFile() string {
diff --git a/internal/adaptercfg/adaptercfg_test.go b/internal/adaptercfg/adaptercfg_test.go
index a967787..1d2d136 100644
--- a/internal/adaptercfg/adaptercfg_test.go
+++ b/internal/adaptercfg/adaptercfg_test.go
@@ -112,3 +112,18 @@ func TestLoadTokenReadsOnlyTheBotToken(t *testing.T) {
 		}
 	}
 }
+
+func TestBotAPIChatIDPrefixesChannelIDs(t *testing.T) {
+	if got := BotAPIChatID(4427430639); got != -1004427430639 {
+		t.Fatalf("BotAPIChatID(4427430639) = %d", got)
+	}
+	if got := BotAPIChatID(-1001); got != -1001 {
+		t.Fatalf("an id already in Bot API form changed: %d", got)
+	}
+	rs := provisioned()
+	rs.Channels[spec.Test] = state.Channel{ChatID: 4427430639, AdminRights: []string{spec.PostMessages}}
+	cfg, err := FromResolved(rs, spec.Test, "ref")
+	if err != nil || cfg.ChatID != -1004427430639 {
+		t.Fatalf("FromResolved chat id = %d, err %v", cfg.ChatID, err)
+	}
+}
diff --git a/scripts/send-post.sh b/scripts/send-post.sh
new file mode 100755
index 0000000..9d965da
--- /dev/null
+++ b/scripts/send-post.sh
@@ -0,0 +1,50 @@
+#!/usr/bin/env bash
+# Send one prepared post (pr-hall-of-helix/posts/<file>.yaml) through a
+# short-lived local adapter, then stop it.
+#
+# Run it yourself, logged in to OpenBao (BAO_ADDR/BAO_TOKEN set). The bot token
+# goes from OpenBao straight into the adapter's environment and is never
+# printed. The adapter's store is in memory, so idempotency on post_id holds
+# only within one run: do not re-run for a post that already went out.
+#
+#   scripts/send-post.sh ~/pr-hall-of-helix/posts/2026-10-08-test-outlet-parametrization.yaml test
+set -euo pipefail
+
+post=$(realpath "$1")
+channel=${2:-test}
+spec=${SPEC:-$HOME/pr-hall-of-helix/presence/telegram.yaml}
+port=${PORT:-18089}
+cd "$(dirname "$0")/.."
+
+read -r want reviewed < <(python3 -c '
+import sys, yaml
+d = yaml.safe_load(open(sys.argv[1]))
+print(d["channel"], d["request"].get("reviewed_by") or "-")' "$post")
+[ "$want" = "$channel" ] || { echo "post is for channel '$want', not '$channel'" >&2; exit 2; }
+[ "$reviewed" != "-" ] || { echo "request.reviewed_by is empty; a person reviews before sending" >&2; exit 2; }
+
+TELEGRAM_CHANNEL_ID=$(go run ./cmd/provision adapter-config --spec "$spec" --channel "$channel" \
+  | sed -n 's/^TELEGRAM_CHANNEL_ID=//p')
+[ -n "$TELEGRAM_CHANNEL_ID" ] || { echo "no chat id for channel '$channel'" >&2; exit 2; }
+
+tmp=$(mktemp -d)
+go build -o "$tmp/adapter" ./cmd/adapter
+
+token=$(bao kv get -mount=platform -field=token \
+  workloads/infotech/fluid-telegram/hall-of-helix/bot-token) \
+  || { rm -rf "$tmp"; echo "could not read the bot token from OpenBao (logged in?)" >&2; exit 2; }
+
+TELEGRAM_BOT_TOKEN=$token TELEGRAM_CHANNEL_ID=$TELEGRAM_CHANNEL_ID \
+  ADAPTER_LISTEN_ADDR=127.0.0.1:$port "$tmp/adapter" &
+pid=$!
+unset token
+trap 'kill $pid 2>/dev/null; rm -rf "$tmp"' EXIT
+
+for _ in $(seq 50); do
+  curl -s -o /dev/null "http://127.0.0.1:$port/" && break
+  sleep 0.1
+done
+
+python3 -c 'import sys, yaml, json; print(json.dumps(yaml.safe_load(open(sys.argv[1]))["request"]))' "$post" \
+  | curl -sS -w '\nHTTP %{http_code}\n' -X POST -H 'Content-Type: application/json' \
+      --data-binary @- "http://127.0.0.1:$port/v1/channel-posts"