[EPIC] Cross-Cluster Agent Identity Federation (SPIFFE/SPIRE)

[shreyanshjain7174]

Summary

Adopt SPIFFE/SPIRE (CNCF graduated) as the workload identity layer to enable verifiable, federated agent identity across Kubernetes clusters. Opt-in per AgentWorkload; ServiceAccount + JWT remains the intra-cluster default.

Why

Enterprise NineVigil deployments span multiple clusters (multi-region, multi-tenant, multi-org). Today an agent in Cluster A has no zero-secret way to authenticate to a service or another agent in Cluster B. Existing options (shared secrets, mTLS without workload identity, central OIDC) all fail for air-gapped and regulated environments — which is exactly our ICP.

Triggered by @JacobSobolev on X (19 May 2026).

Design

Full design proposal: docs/rfcs/0001-cross-cluster-agent-identity.md

Validation gate (HARD)

This epic is in signal-collection mode. No implementation work begins until either:

• 6+ distinct external use cases in the linked GitHub Discussion (each comment naming a concrete deployment scenario), OR
• 1 paying customer explicitly requests this feature in writing.

Until the gate clears, only the RFC and tracking issues are active work.

Roadmap

• Tentative target: v0.4.0 (Q3 2026)
• ROADMAP entry: ROADMAP.md § Exploring

Stories (sub-issues)

Linked below as sub-issues. All stories beyond Story 1 (RFC authoring) and Story 2 (validation gate) are blocked until the gate clears.

Related roadmap issues

After roadmap reconciliation on 2026-05-19, this epic absorbs and cross-links the following pre-existing issues. Each is preserved with the appropriate scope; this epic is the canonical implementation tracker:

Absorbed (closed as superseded):

• Cross-organizational trust — federated SPIFFE trust domains for inter-org agent communication #122 — Cross-organizational trust — federated SPIFFE trust domains (fully duplicate; closed)

Cross-linked (kept open, implementation tracked here):

• Per-instance SPIFFE SVIDs — provision unique identity per agent instance, not per service account #107 — Per-instance SPIFFE SVIDs → stories [Story] SPIRE Workload API integration (sidecar/init/hostpath modes) #148, [Story] AgentWorkload CRD: spec.identity.spiffe fields #156
• mTLS between agents — automatic mutual TLS for all A2A communication within the mesh #108 — mTLS between agents → composable with story [Story] A2A protocol v2 handshake with JWT-SVID #149 (mTLS at transport + JWT-SVID at A2A application layer)
• Certificate rotation — short-lived certs (1h TTL) with automated renewal via SPIRE #109 — Certificate rotation via SPIRE → implicit dependency, covered by story [Story] SPIRE Workload API integration (sidecar/init/hostpath modes) #148
• ACME agent enrollment — extend ACME protocol for automated agent certificate provisioning #106 — ACME agent enrollment → now a properly considered alternative in RFC §8

Related but distinct scope (no implementation overlap):

• Multi-cluster discovery — agents in cluster A discover and invoke agents in cluster B #121 — Multi-cluster discovery (discovery layer; this epic is identity layer)
• Registry federation — cross-cluster registry sync with bounded staleness (<60s) #102 — Registry federation (registry data plane; this epic is identity)

Related

• Discussion (pending): to be linked once opened
• A2A protocol: docs/a2a-architecture.md
• Threat model: docs/security/threat-model.md