BlastShield

BlastShield is a prototype entry for Track 01 of the Graph Hacks 2026 hackathon, using the graph database FalkorDB to hold access relationships, constrained tools to bound Gemini's behavior, and re-querying after each action to verify results.

BlastShield's graph model contains five entity types: Identity, Session, Workload, IAMRole, and DataAsset.

The edges in BlastShield's graph model include HAS_SESSION, CAN_ACCESS, RUNS_AS, CAN_ASSUME, and CAN_READ, and the edges carry attributes such as route identifiers, containment and response status, permission assessments, and sensitivity.

BlastShield includes four typical scenarios: identity access path (BH-1042, medium severity, 35 points), excessive IAM permissions (BH-IAM-2001, high severity, 65 points), exposed workload (BH-WORKLOAD-3001, high severity, 75 points), and containment scenario (BH-CONTAINMENT-4001, high severity, 60 points), with scores coming from the demo rule set demo-rules-v1.

BlastShield uses bounded directed traversal, the depth passed by the caller is validated as an integer between 1 and 6, corresponding to six prebuilt query templates, and caller text is never concatenated into Cypher.

BlastShield exposes a set of reviewed fixed tools: investigate_alert(alert_id), get_blast_radius(alert_id), find_shortest_access_path(source_id, target_id, max_hops), get_containment_route_statuses(alert_id).

BlastShield separates 'proposed actions' from 'executed actions' and sets up three layers of boundaries: the decision service only provides read-only tools to obtain response candidates; the FastAPI controller requires explicit confirmation and limits the number of actions per run; and an independent action service holds the only mutation capability and performs at most one allowlisted write against the synthetic graph.

In the BH-CONTAINMENT-4001 scenario, the seed model has two independent paths, and the controller re-queries FalkorDB after each action, with the expected sequence being: block the primary path, re-query and discover the alternate path, block the alternate path, and query again to confirm no qualifying paths remain.

BlastShield's latest backend test run reports 32 passed and 6 skipped, with the 6 skipped being real FalkorDB tests that require explicit enabling.

BlastShield does not integrate native graph algorithms, and the shortest-path tool uses bounded Cypher traversal rather than algo.SPpaths; it has no persistent graph memory, and the containment audit history is stored in process memory and cleared on API restart; it uses only synthetic data and does not connect to any cloud account.

All of BlastShield's data is synthetic and does not connect to real cloud accounts, identity providers, or production telemetry; a path represents reachability in the model and does not mean the real environment has been exploited; and the absence of a qualifying path in the graph does not prove the real environment is safe.

When the action response lacks an after object, the controller must obtain a standard investigation from FalkorDB to avoid making the next decision based on stale evidence.