enhanced alert granularity with min/max thresholds

backend/infra/migrations/008_add_min_max_to_alert_rules.sql

@@ -0,0 +1,6 @@
+ALTER TABLE alert_rules ADD COLUMN minimum DECIMAL(20, 6);
+ALTER TABLE alert_rules ADD COLUMN maximum DECIMAL(20, 6);
+
+ALTER TABLE alert_rules ADD CONSTRAINT non_negative_minimum CHECK (minimum IS NULL OR minimum >= 0);
+ALTER TABLE alert_rules ADD CONSTRAINT non_negative_maximum CHECK (maximum IS NULL OR maximum >= 0);
+ALTER TABLE alert_rules ADD CONSTRAINT min_lte_max CHECK (minimum IS NULL OR maximum IS NULL OR minimum <= maximum);

backend/infra/schema.sql

@@ -35,6 +35,8 @@ CREATE TABLE alert_rules (
   address_id INTEGER NOT NULL REFERENCES addresses(id) ON DELETE CASCADE,
   type VARCHAR(50) NOT NULL,           -- 'incoming_tx', 'outgoing_tx', 'large_transfer', 'balance_below'
   threshold DECIMAL(20, 6),            -- ETH amount threshold (nullable for tx types that don't need it)
+  minimum DECIMAL(20, 6),              -- Optional min amount filter for incoming/outgoing alerts
+  maximum DECIMAL(20, 6),              -- Optional max amount filter for incoming/outgoing alerts
   enabled BOOLEAN DEFAULT TRUE,
   created_at TIMESTAMP DEFAULT NOW(),
 
@@ -44,7 +46,11 @@ CREATE TABLE alert_rules (
 
   CONSTRAINT positive_threshold CHECK (
     threshold IS NULL OR threshold > 0
-  )
+  ),
+
+  CONSTRAINT non_negative_minimum CHECK (minimum IS NULL OR minimum >= 0),
+  CONSTRAINT non_negative_maximum CHECK (maximum IS NULL OR maximum >= 0),
+  CONSTRAINT min_lte_max CHECK (minimum IS NULL OR maximum IS NULL OR minimum <= maximum)
 );
 
 

backend/internal/domain/types.go

@@ -73,6 +73,8 @@ type AlertRule struct {
 	AddressID int       `json:"address_id"` //nolint:tagliatelle
 	Type      AlertType `json:"type"`
 	Threshold *float64  `json:"threshold"`
+	Minimum   *float64  `json:"minimum"`
+	Maximum   *float64  `json:"maximum"`
 	Enabled   bool      `json:"enabled"`
 	CreatedAt time.Time `json:"created_at"` //nolint:tagliatelle
 }

backend/internal/handlers/alert_rule.go

@@ -37,6 +37,8 @@ func (h *AlertRuleHandler) Create(w http.ResponseWriter, r *http.Request) {
 	var body struct {
 		Type      string          `json:"type"`
 		Threshold json.RawMessage `json:"threshold"`
+		Minimum   json.RawMessage `json:"minimum"`
+		Maximum   json.RawMessage `json:"maximum"`
 	}
 	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
 		log.Printf("Failed to decode alert request body: %v", err)
@@ -53,6 +55,40 @@ func (h *AlertRuleHandler) Create(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	minimum, err := parseThreshold(body.Minimum)
+	if err != nil {
+		log.Printf("Failed to parse minimum: %v", err)
+		writeError(w, http.StatusBadRequest, "VALIDATION_ERROR", "minimum must be a valid number")
+
+		return
+	}
+
+	maximum, err := parseThreshold(body.Maximum)
+	if err != nil {
+		log.Printf("Failed to parse maximum: %v", err)
+		writeError(w, http.StatusBadRequest, "VALIDATION_ERROR", "maximum must be a valid number")
+
+		return
+	}
+
+	if minimum != nil && *minimum < 0 {
+		writeError(w, http.StatusBadRequest, "VALIDATION_ERROR", "minimum must be non-negative")
+
+		return
+	}
+
+	if maximum != nil && *maximum < 0 {
+		writeError(w, http.StatusBadRequest, "VALIDATION_ERROR", "maximum must be non-negative")
+
+		return
+	}
+
+	if minimum != nil && maximum != nil && *minimum > *maximum {
+		writeError(w, http.StatusBadRequest, "VALIDATION_ERROR", "minimum must not exceed maximum")
+
+		return
+	}
+
 	log.Printf("User %s creating alert: type=%s, addressID=%d", userID, body.Type, addressID)
 
 	if body.Type == "" {
@@ -96,7 +132,7 @@ func (h *AlertRuleHandler) Create(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	newAlert, err := h.alertRules.Create(r.Context(), addressID, alertType, threshold)
+	newAlert, err := h.alertRules.Create(r.Context(), addressID, alertType, threshold, minimum, maximum)
 	if err != nil {
 		log.Printf("Error creating alert rule: %v", err)
 		writeError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "Failed to create alert rule")
@@ -182,7 +218,7 @@ func (h *AlertRuleHandler) ListByAddress(w http.ResponseWriter, r *http.Request)
 	writeJSON(w, http.StatusOK, alerts)
 }
 
-// UpdateStatus handles PATCH requests to enable or disable an alert rule.
+// UpdateStatus handles PATCH requests to enable/disable an alert rule and/or update min/max thresholds.
 func (h *AlertRuleHandler) UpdateStatus(w http.ResponseWriter, r *http.Request) {
 	userID := middleware.GetUserID(r.Context())
 	alertID, ok := parseIntParam(r.PathValue("alertId"))
@@ -193,7 +229,10 @@ func (h *AlertRuleHandler) UpdateStatus(w http.ResponseWriter, r *http.Request)
 	}
 
 	var body struct {
-		Enabled *bool `json:"enabled"`
+		Enabled        *bool           `json:"enabled"`
+		Minimum        json.RawMessage `json:"minimum"`
+		Maximum        json.RawMessage `json:"maximum"`
+		UpdateMinMax   bool            `json:"update_min_max"`   //nolint:tagliatelle
 	}
 	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
 		log.Printf("Failed to decode update request body: %v", err)
@@ -204,8 +243,8 @@ func (h *AlertRuleHandler) UpdateStatus(w http.ResponseWriter, r *http.Request)
 
 	log.Printf("User %s updating alert ID: %d", userID, alertID)
 
-	if body.Enabled == nil {
-		writeError(w, http.StatusBadRequest, "VALIDATION_ERROR", "enabled must be a boolean value")
+	if body.Enabled == nil && !body.UpdateMinMax {
+		writeError(w, http.StatusBadRequest, "VALIDATION_ERROR", "must provide enabled (boolean) or update_min_max with minimum/maximum values")
 
 		return
 	}
@@ -224,15 +263,64 @@ func (h *AlertRuleHandler) UpdateStatus(w http.ResponseWriter, r *http.Request)
 		return
 	}
 
-	updated, err := h.alertRules.UpdateEnabled(r.Context(), alertID, *body.Enabled)
-	if err != nil {
-		log.Printf("Error updating alert: %v", err)
-		writeError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "Failed to update alert")
+	var updated *domain.AlertRule
 
-		return
+	if body.UpdateMinMax {
+		minimum, parseErr := parseThreshold(body.Minimum)
+		if parseErr != nil {
+			writeError(w, http.StatusBadRequest, "VALIDATION_ERROR", "minimum must be a valid number")
+
+			return
+		}
+
+		maximum, parseErr := parseThreshold(body.Maximum)
+		if parseErr != nil {
+			writeError(w, http.StatusBadRequest, "VALIDATION_ERROR", "maximum must be a valid number")
+
+			return
+		}
+
+		if minimum != nil && *minimum < 0 {
+			writeError(w, http.StatusBadRequest, "VALIDATION_ERROR", "minimum must be non-negative")
+
+			return
+		}
+
+		if maximum != nil && *maximum < 0 {
+			writeError(w, http.StatusBadRequest, "VALIDATION_ERROR", "maximum must be non-negative")
+
+			return
+		}
+
+		if minimum != nil && maximum != nil && *minimum > *maximum {
+			writeError(w, http.StatusBadRequest, "VALIDATION_ERROR", "minimum must not exceed maximum")
+
+			return
+		}
+
+		updated, err = h.alertRules.UpdateThresholds(r.Context(), alertID, minimum, maximum)
+		if err != nil {
+			log.Printf("Error updating alert thresholds: %v", err)
+			writeError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "Failed to update alert")
+
+			return
+		}
+
+		log.Printf("Alert %d thresholds updated: min=%v, max=%v", alertID, minimum, maximum)
+	}
+
+	if body.Enabled != nil {
+		updated, err = h.alertRules.UpdateEnabled(r.Context(), alertID, *body.Enabled)
+		if err != nil {
+			log.Printf("Error updating alert: %v", err)
+			writeError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "Failed to update alert")
+
+			return
+		}
+
+		log.Printf("Alert %d updated: enabled=%v", alertID, *body.Enabled)
 	}
 
-	log.Printf("Alert %d updated: enabled=%v", alertID, *body.Enabled)
 	writeJSON(w, http.StatusOK, updated)
 }
 

backend/internal/models/alert_rule.go

@@ -17,14 +17,14 @@ func NewAlertRuleModel(pool *pgxpool.Pool) *AlertRuleModel {
 	return &AlertRuleModel{pool: pool}
 }
 
-func (m *AlertRuleModel) Create(ctx context.Context, addressID int, alertType domain.AlertType, threshold *float64) (*domain.AlertRule, error) {
+func (m *AlertRuleModel) Create(ctx context.Context, addressID int, alertType domain.AlertType, threshold, minimum, maximum *float64) (*domain.AlertRule, error) {
 	var r domain.AlertRule
 	err := m.pool.QueryRow(ctx,
-		`INSERT INTO alert_rules (address_id, type, threshold, enabled)
-		 VALUES ($1, $2, $3, TRUE)
-		 RETURNING id, address_id, type, threshold, enabled, created_at`,
-		addressID, alertType.String(), threshold,
-	).Scan(&r.ID, &r.AddressID, &r.Type, &r.Threshold, &r.Enabled, &r.CreatedAt)
+		`INSERT INTO alert_rules (address_id, type, threshold, minimum, maximum, enabled)
+		 VALUES ($1, $2, $3, $4, $5, TRUE)
+		 RETURNING id, address_id, type, threshold, minimum, maximum, enabled, created_at`,
+		addressID, alertType.String(), threshold, minimum, maximum,
+	).Scan(&r.ID, &r.AddressID, &r.Type, &r.Threshold, &r.Minimum, &r.Maximum, &r.Enabled, &r.CreatedAt)
 	if err != nil {
 		return nil, err
 	}
@@ -33,7 +33,7 @@ func (m *AlertRuleModel) Create(ctx context.Context, addressID int, alertType do
 
 func (m *AlertRuleModel) ListByAddress(ctx context.Context, addressID int) ([]domain.AlertRule, error) {
 	rows, err := m.pool.Query(ctx,
-		`SELECT id, address_id, type, threshold, enabled, created_at
+		`SELECT id, address_id, type, threshold, minimum, maximum, enabled, created_at
 		 FROM alert_rules
 		 WHERE address_id = $1
 		 ORDER BY created_at DESC`,
@@ -47,7 +47,7 @@ func (m *AlertRuleModel) ListByAddress(ctx context.Context, addressID int) ([]do
 	var rules []domain.AlertRule
 	for rows.Next() {
 		var r domain.AlertRule
-		if err := rows.Scan(&r.ID, &r.AddressID, &r.Type, &r.Threshold, &r.Enabled, &r.CreatedAt); err != nil {
+		if err := rows.Scan(&r.ID, &r.AddressID, &r.Type, &r.Threshold, &r.Minimum, &r.Maximum, &r.Enabled, &r.CreatedAt); err != nil {
 			return nil, err
 		}
 		rules = append(rules, r)
@@ -61,19 +61,19 @@ func (m *AlertRuleModel) FindByID(ctx context.Context, id int, userID *string) (
 
 	if userID != nil {
 		err = m.pool.QueryRow(ctx,
-			`SELECT ar.id, ar.address_id, ar.type, ar.threshold, ar.enabled, ar.created_at
+			`SELECT ar.id, ar.address_id, ar.type, ar.threshold, ar.minimum, ar.maximum, ar.enabled, ar.created_at
 			 FROM alert_rules ar
 			 JOIN addresses a ON a.id = ar.address_id
 			 WHERE ar.id = $1 AND a.user_id = $2`,
 			id, *userID,
-		).Scan(&r.ID, &r.AddressID, &r.Type, &r.Threshold, &r.Enabled, &r.CreatedAt)
+		).Scan(&r.ID, &r.AddressID, &r.Type, &r.Threshold, &r.Minimum, &r.Maximum, &r.Enabled, &r.CreatedAt)
 	} else {
 		err = m.pool.QueryRow(ctx,
-			`SELECT id, address_id, type, threshold, enabled, created_at
+			`SELECT id, address_id, type, threshold, minimum, maximum, enabled, created_at
 			 FROM alert_rules
 			 WHERE id = $1`,
 			id,
-		).Scan(&r.ID, &r.AddressID, &r.Type, &r.Threshold, &r.Enabled, &r.CreatedAt)
+		).Scan(&r.ID, &r.AddressID, &r.Type, &r.Threshold, &r.Minimum, &r.Maximum, &r.Enabled, &r.CreatedAt)
 	}
 
 	if err != nil {
@@ -91,9 +91,27 @@ func (m *AlertRuleModel) UpdateEnabled(ctx context.Context, id int, enabled bool
 		`UPDATE alert_rules
 		 SET enabled = $2
 		 WHERE id = $1
-		 RETURNING id, address_id, type, threshold, enabled, created_at`,
+		 RETURNING id, address_id, type, threshold, minimum, maximum, enabled, created_at`,
 		id, enabled,
-	).Scan(&r.ID, &r.AddressID, &r.Type, &r.Threshold, &r.Enabled, &r.CreatedAt)
+	).Scan(&r.ID, &r.AddressID, &r.Type, &r.Threshold, &r.Minimum, &r.Maximum, &r.Enabled, &r.CreatedAt)
+	if err != nil {
+		if errors.Is(err, pgx.ErrNoRows) {
+			return nil, nil
+		}
+		return nil, err
+	}
+	return &r, nil
+}
+
+func (m *AlertRuleModel) UpdateThresholds(ctx context.Context, id int, minimum, maximum *float64) (*domain.AlertRule, error) {
+	var r domain.AlertRule
+	err := m.pool.QueryRow(ctx,
+		`UPDATE alert_rules
+		 SET minimum = $2, maximum = $3
+		 WHERE id = $1
+		 RETURNING id, address_id, type, threshold, minimum, maximum, enabled, created_at`,
+		id, minimum, maximum,
+	).Scan(&r.ID, &r.AddressID, &r.Type, &r.Threshold, &r.Minimum, &r.Maximum, &r.Enabled, &r.CreatedAt)
 	if err != nil {
 		if errors.Is(err, pgx.ErrNoRows) {
 			return nil, nil

backend/internal/services/evaluator.go

@@ -104,9 +104,9 @@ func (s *EvaluatorService) evaluateObservation(ctx context.Context, obs domain.O
 func (s *EvaluatorService) ruleMatches(ctx context.Context, rule domain.AlertRule, obs domain.ObservedTx) (bool, error) {
 	switch rule.Type {
 	case domain.AlertIncomingTx:
-		return obs.Direction == domain.DirectionIncoming, nil
+		return s.matchesDirectionalTx(rule, obs, domain.DirectionIncoming)
 	case domain.AlertOutgoingTx:
-		return obs.Direction == domain.DirectionOutgoing, nil
+		return s.matchesDirectionalTx(rule, obs, domain.DirectionOutgoing)
 	case domain.AlertLargeTransfer:
 		return s.matchesLargeTransfer(rule, obs)
 	case domain.AlertBalanceBelow:
@@ -117,6 +117,42 @@ func (s *EvaluatorService) ruleMatches(ctx context.Context, rule domain.AlertRul
 	}
 }
 
+func (s *EvaluatorService) matchesDirectionalTx(rule domain.AlertRule, obs domain.ObservedTx, expected domain.Direction) (bool, error) {
+	if obs.Direction != expected {
+		return false, nil
+	}
+
+	if rule.Minimum != nil {
+		minWei, err := wei.FromEth(*rule.Minimum)
+		if err != nil {
+			return false, err
+		}
+		aboveMin, err := wei.GreaterThanOrEqual(obs.Value, minWei)
+		if err != nil {
+			return false, err
+		}
+		if !aboveMin {
+			return false, nil
+		}
+	}
+
+	if rule.Maximum != nil {
+		maxWei, err := wei.FromEth(*rule.Maximum)
+		if err != nil {
+			return false, err
+		}
+		belowMax, err := wei.LessThanOrEqual(obs.Value, maxWei)
+		if err != nil {
+			return false, err
+		}
+		if !belowMax {
+			return false, nil
+		}
+	}
+
+	return true, nil
+}
+
 func (s *EvaluatorService) matchesLargeTransfer(rule domain.AlertRule, obs domain.ObservedTx) (bool, error) {
 	if rule.Threshold == nil {
 		return false, nil

backend/internal/wei/converter.go

@@ -90,6 +90,14 @@ func LessThan(weiA, weiB string) (bool, error) {
 	return cmp < 0, nil
 }
 
+func LessThanOrEqual(weiA, weiB string) (bool, error) {
+	cmp, err := Compare(weiA, weiB)
+	if err != nil {
+		return false, err
+	}
+	return cmp <= 0, nil
+}
+
 // FormatAsEth formats a Wei string as "X.XXXX ETH".
 func FormatAsEth(weiString string, decimals int) (string, error) {
 	eth, err := ToEth(weiString)