diff --git a/.env.example b/.env.example
index 8eef2fc..3de6771 100644
--- a/.env.example
+++ b/.env.example
@@ -23,8 +23,9 @@ ADMIN_IDS=
 # Only the twentyq module needs this. Leave blank to disable that command.
 GEMINI_API_KEY=
 
-# SOURCE_COMMIT is injected as a build arg by Coolify (it sets it automatically)
-# for the deploynotify owner DM. Leave unset for local `docker compose up` —
+# SOURCE_COMMIT is injected into the container at runtime by Coolify (a
+# predefined env var holding the commit SHA); read at startup for the
+# deploynotify owner DM. Leave unset for local `docker compose up` —
 # deploynotify just stays silent.
 # SOURCE_COMMIT=
 
diff --git a/Dockerfile b/Dockerfile
index 47e3b60..7e3560a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -6,15 +6,11 @@ RUN go mod download
 
 COPY . .
 
-# SOURCE_COMMIT is baked into the binary so internal/deploynotify can DM the
-# owner once per new version (parity with the Makefile build). Coolify exposes
-# the commit SHA as the SOURCE_COMMIT build arg automatically — no manual
-# wiring needed. For a manual build, pass it with
-#   --build-arg SOURCE_COMMIT=$(git rev-parse --short HEAD)
-# When unset, deploynotify treats the empty SHA as "stay silent".
-ARG SOURCE_COMMIT=""
+# The deploy-notify commit SHA comes from the SOURCE_COMMIT runtime env that
+# Coolify injects into the container (see docker-compose.yml), not from a build
+# arg — Coolify does not pass build args here. The binary is built plain.
 RUN CGO_ENABLED=0 GOOS=linux go build \
-    -ldflags="-s -w -X main.gitSHA=${SOURCE_COMMIT}" \
+    -ldflags="-s -w" \
     -o /out/server \
     ./cmd/server
 
diff --git a/cmd/server/main.go b/cmd/server/main.go
index e9c4899..872c7d7 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -36,11 +36,22 @@ import (
 	"github.com/tiennm99/miti99bot/internal/telegram"
 )
 
-// gitSHA is populated at build time via `-ldflags "-X main.gitSHA=<sha>"`
-// (see Makefile). Empty value means the binary was built without that flag —
-// deploynotify treats it as a signal to stay silent.
+// gitSHA is the local-build fallback, populated via `-ldflags "-X
+// main.gitSHA=<sha>"` (see Makefile). On Coolify the commit comes from the
+// SOURCE_COMMIT runtime env instead (resolveCommitSHA prefers it). Empty from
+// both sources means deploynotify stays silent.
 var gitSHA string
 
+// resolveCommitSHA returns the commit identifier for the deploy notification.
+// Coolify injects SOURCE_COMMIT into the container environment at runtime, so
+// prefer it; fall back to the ldflags-baked gitSHA for local builds.
+func resolveCommitSHA(envSourceCommit string) string {
+	if s := strings.TrimSpace(envSourceCommit); s != "" {
+		return s
+	}
+	return gitSHA
+}
+
 // factories is the static module catalog. Adding a new module is a one-line
 // change here. Lives in main rather than the modules package to avoid an
 // import cycle (modules → util → modules).
@@ -157,7 +168,7 @@ func main() {
 		Bot:     b,
 		Store:   deploynotify.NewStore(provider.Collection("deploynotify")),
 		OwnerID: cfg.BotOwnerID,
-		GitSHA:  gitSHA,
+		GitSHA:  resolveCommitSHA(cfg.SourceCommit),
 	})
 
 	handler := server.New()
@@ -260,6 +271,7 @@ func buildProvider(ctx context.Context, cfg config) (storage.Provider, func(), e
 type config struct {
 	Port                  string
 	TelegramBotToken      string
+	SourceCommit          string // Coolify-injected commit SHA (runtime env) for deploynotify
 	GeminiAPIKey          string
 	GoldPriceAPIURL       string
 	GoldFXAPIURL          string
@@ -299,6 +311,7 @@ func loadConfig() config {
 	return config{
 		Port:                  port,
 		TelegramBotToken:      envMap["TELEGRAM_BOT_TOKEN"],
+		SourceCommit:          envMap["SOURCE_COMMIT"],
 		GeminiAPIKey:          envMap["GEMINI_API_KEY"],
 		GoldPriceAPIURL:       envMap["GOLD_PRICE_API_URL"],
 		GoldFXAPIURL:          envMap["GOLD_FX_API_URL"],
diff --git a/cmd/server/main_test.go b/cmd/server/main_test.go
index b15745e..b1918d7 100644
--- a/cmd/server/main_test.go
+++ b/cmd/server/main_test.go
@@ -7,6 +7,28 @@ import (
 	"github.com/tiennm99/miti99bot/internal/storage"
 )
 
+func TestResolveCommitSHA(t *testing.T) {
+	prev := gitSHA
+	defer func() { gitSHA = prev }()
+
+	// Coolify runtime env wins over the baked fallback.
+	gitSHA = "baked"
+	if got := resolveCommitSHA("  runtime-sha "); got != "runtime-sha" {
+		t.Errorf("env present: got %q, want trimmed runtime-sha", got)
+	}
+
+	// Empty env falls back to the ldflags-baked value.
+	if got := resolveCommitSHA(""); got != "baked" {
+		t.Errorf("env empty: got %q, want baked fallback", got)
+	}
+
+	// Neither source set → empty (deploynotify stays silent).
+	gitSHA = ""
+	if got := resolveCommitSHA("   "); got != "" {
+		t.Errorf("both empty: got %q, want empty", got)
+	}
+}
+
 func TestFactoriesIncludesGoldAndCoin(t *testing.T) {
 	catalog := factories()
 	if catalog["gold"] == nil {
diff --git a/docker-compose.yml b/docker-compose.yml
index aaa7a4a..5c88dcb 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -2,10 +2,6 @@ services:
   bot:
     build:
       context: .
-      args:
-        # Coolify sets SOURCE_COMMIT automatically; passed so deploynotify DMs
-        # the owner on each new version. Optional — empty SHA just stays silent.
-        SOURCE_COMMIT: ${SOURCE_COMMIT:-}
     # Or pin a prebuilt image instead of building:
     #   image: ghcr.io/tiennm99/miti99bot:latest
     restart: unless-stopped
@@ -20,6 +16,10 @@ services:
       ADMIN_IDS: ${ADMIN_IDS}              # CSV of admin Telegram user ids
       # --- Optional ---
       GEMINI_API_KEY: ${GEMINI_API_KEY}    # only the twentyq module needs it
+      # Coolify injects SOURCE_COMMIT (commit SHA) at deploy time; passed to the
+      # container so deploynotify DMs the owner once per new version. Empty (e.g.
+      # local `docker compose up` without it) just stays silent.
+      SOURCE_COMMIT: ${SOURCE_COMMIT:-}
       # Storage auto-selects mongodb because MONGO_URL is set — no KV_PROVIDER.
       # The in-process cron scheduler runs by default — no CRON_MODE.
       # PORT defaults to 8080 (internal health server) — omit unless overriding.
diff --git a/docs/deploy-coolify-selfhosted.md b/docs/deploy-coolify-selfhosted.md
index 80570fb..f03fc1b 100644
--- a/docs/deploy-coolify-selfhosted.md
+++ b/docs/deploy-coolify-selfhosted.md
@@ -88,10 +88,11 @@ SSM/AWS lookup that fails with no AWS creds and bricks startup), `KV_PROVIDER`,
    bot token; a second poller gets HTTP 409, and a second in-process scheduler
    double-fires crons. Prefer **stop-first redeploys** so two containers never
    overlap near a cron time.
-5. **Build arg for deploynotify:** Coolify sets `SOURCE_COMMIT` automatically
-   and the compose build forwards it, so the owner gets the "new version" DM
-   with no manual wiring. Without it, `deploynotify` stays silent (no crash) —
-   but you lose that notification.
+5. **deploynotify commit SHA:** Coolify injects `SOURCE_COMMIT` (a predefined
+   runtime env var) into the container, and the compose `environment` forwards
+   it, so the bot reads it at startup and DMs the owner the "new version"
+   notice — no manual wiring. Without it, `deploynotify` stays silent (no
+   crash) — but you lose that notification.
 6. **Health check:** use Coolify's HTTP monitor against `GET /` (returns
    `text/plain` `miti99bot ok`). Do **not** use a compose `healthcheck` — the
    distroless image has no shell/curl and `cmd/server` has no `-healthcheck`