diff --git a/internal/storage/sqlite/external_deps.go b/internal/storage/sqlite/external_deps.go
new file mode 100644
index 00000000..e28dbfd5
--- /dev/null
+++ b/internal/storage/sqlite/external_deps.go
@@ -0,0 +1,129 @@
+// Package sqlite provides external dependency resolution for cross-project blocking.
+//
+// External dependencies use the format: external:<project>:<capability>
+// They are satisfied when:
+//   - The project is configured in external_projects config
+//   - The project's beads database has a closed issue with provides:<capability> label
+//
+// Resolution happens lazily at query time (GetReadyWork) rather than during
+// cache rebuild, to keep cache rebuilds fast and avoid holding multiple DB connections.
+package sqlite
+
+import (
+	"context"
+	"database/sql"
+	"path/filepath"
+	"strings"
+
+	"github.com/steveyegge/beads/internal/config"
+	"github.com/steveyegge/beads/internal/configfile"
+)
+
+// ExternalDepStatus represents whether an external dependency is satisfied
+type ExternalDepStatus struct {
+	Ref        string // The full external reference (external:project:capability)
+	Project    string // Parsed project name
+	Capability string // Parsed capability name
+	Satisfied  bool   // Whether the dependency is satisfied
+	Reason     string // Human-readable reason if not satisfied
+}
+
+// CheckExternalDep checks if a single external dependency is satisfied.
+// Returns status information about the dependency.
+func CheckExternalDep(ctx context.Context, ref string) *ExternalDepStatus {
+	status := &ExternalDepStatus{
+		Ref:       ref,
+		Satisfied: false,
+	}
+
+	// Parse external:project:capability
+	if !strings.HasPrefix(ref, "external:") {
+		status.Reason = "not an external reference"
+		return status
+	}
+
+	parts := strings.SplitN(ref, ":", 3)
+	if len(parts) != 3 {
+		status.Reason = "invalid format (expected external:project:capability)"
+		return status
+	}
+
+	status.Project = parts[1]
+	status.Capability = parts[2]
+
+	if status.Project == "" || status.Capability == "" {
+		status.Reason = "missing project or capability"
+		return status
+	}
+
+	// Look up project path from config
+	projectPath := config.ResolveExternalProjectPath(status.Project)
+	if projectPath == "" {
+		status.Reason = "project not configured in external_projects"
+		return status
+	}
+
+	// Find the beads database in the project
+	beadsDir := filepath.Join(projectPath, ".beads")
+	cfg, err := configfile.Load(beadsDir)
+	if err != nil || cfg == nil {
+		status.Reason = "project has no beads database"
+		return status
+	}
+
+	dbPath := cfg.DatabasePath(beadsDir)
+
+	// Open the external database (read-only)
+	db, err := sql.Open("sqlite3", dbPath+"?mode=ro")
+	if err != nil {
+		status.Reason = "cannot open project database"
+		return status
+	}
+	defer func() { _ = db.Close() }()
+
+	// Check for a closed issue with provides:<capability> label
+	providesLabel := "provides:" + status.Capability
+	var count int
+	err = db.QueryRowContext(ctx, `
+		SELECT COUNT(*) FROM issues i
+		JOIN labels l ON i.id = l.issue_id
+		WHERE i.status = 'closed'
+		  AND l.label = ?
+	`, providesLabel).Scan(&count)
+
+	if err != nil {
+		status.Reason = "database query failed"
+		return status
+	}
+
+	if count == 0 {
+		status.Reason = "capability not shipped (no closed issue with provides:" + status.Capability + " label)"
+		return status
+	}
+
+	status.Satisfied = true
+	status.Reason = "capability shipped"
+	return status
+}
+
+// CheckExternalDeps checks multiple external dependencies.
+// Returns a map of ref -> status.
+func CheckExternalDeps(ctx context.Context, refs []string) map[string]*ExternalDepStatus {
+	results := make(map[string]*ExternalDepStatus)
+	for _, ref := range refs {
+		results[ref] = CheckExternalDep(ctx, ref)
+	}
+	return results
+}
+
+// GetUnsatisfiedExternalDeps returns external dependencies that are not satisfied.
+func GetUnsatisfiedExternalDeps(ctx context.Context, refs []string) []string {
+	var unsatisfied []string
+	for _, ref := range refs {
+		status := CheckExternalDep(ctx, ref)
+		if !status.Satisfied {
+			unsatisfied = append(unsatisfied, ref)
+		}
+	}
+	return unsatisfied
+}