Keystone Applied Intelligence
Governed AI infrastructure for regulated industries
Authorization-first retrieval, governed conversational agents, and portable evaluation infrastructure — for environments where wrong answers, unauthorized retrieval, or unaudited actions create legal, regulatory, operational, or safety risk.
Runs on customer-controlled infrastructure with local models. No external API dependency for core operation. Air-gap capable.
A platform, not a point solution
Keystone is one platform spanning three workloads for regulated AI systems. They are not separate products bolted together — they share a common governance substrate, so identity, task state, coordination, and proof behave the same way across all three.
Governed conversational agents for regulated customer interaction
Severity-tier escalation, per-step evidence gating, and human-in-the-loop routing for high-consequence interactions — enforced in the orchestration layer, not the prompt.
Public eval: keystone-engage/agent-v1 · 100/100 (70/70 core-regression, 25/25 architecture, 5/5 edge-case)
Public repo: keystone-engage
Authorization-first retrieval for legal, financial, and compliance content
Classification-aware, client-isolated access control enforced by a WHERE clause in the retrieval query, evidence-backed answers with citations, and fail-closed refusal when evidence is insufficient.
Evidence: cross-client isolation regression test (denial verified on both filtered and unfiltered paths). No sealed eval baseline yet.
Public repo: keystone-counsel
Portable evaluation infrastructure for governed AI systems
Structured, reproducible eval artifacts with a public failing-to-passing lineage — the evidence behind every capability claim, reusable across workloads and deployments. The ledger seals and versions them.
Public ledger: keystone-ledger
Shared substrate
One governance substrate underneath all three
Every workload inherits the same control-plane primitives, so governance is consistent by construction rather than re-implemented per product.
- › Agent identity and roles
- › Task lifecycle state management
- › Event-driven coordination
- › Dispatch abstraction
- › Reproducible evaluation artifacts, sealed in the ledger
Operational discipline for the LLM era
The enterprise contact-center industry solved severity-tier escalation, per-step validation, compliance logging, confidence-threshold refusal, and policy-aware routing long before LLM products rediscovered these needs. Keystone carries that discipline into the LLM era and implements it as architecture rather than prompt instructions.
Structural controls, not prompt instructions
Governance is enforced in the retrieval flow, the orchestration layer, the database model, and the audit chain — outside the language model. A control that lives only in a prompt can be reworded away. These cannot.
Evidence-backed answers
Every answer cites the specific source document and section it draws from. No unsupported assertions.
Fail-closed refusal
When evidence is insufficient, or a query is outside corpus scope, the system refuses rather than guessing — with separate, audited refusal reasons.
Query-time role-based access control
Roles are checked before retrieval runs. In the governed-retrieval extensions, unauthorized documents are excluded by a WHERE clause in the database query and never enter the query context; the conversational extension enforces corpus-scope authorization. Both fail closed.
Human review for high-consequence actions
Severity-tier routing sends high-consequence interactions to a human before they complete, not after.
Factual consistency scoring
A dedicated model (Vectara HHEM-2.1-Open) independently scores whether each generated answer is supported by retrieved evidence. Below-threshold answers are withheld. When the scorer model is unavailable, the score is recorded as unavailable and the answer is not blocked on it.
Audit trail with integrity checks
Every query and every refusal is written to an append-only audit trail. Engage and Counsel hash-chain entries with SHA-256 and verify the full chain on replay. Gov signs each entry with a keyed HMAC-SHA256 integrity check (per-record verification, not a chain walk).
Claims backed by public eval artifacts
Capability claims map to versioned evaluation artifacts in the public ledger — quantitative baselines, a documented remediation history, and a failing-to-passing lineage. Proof artifacts, not roadmap language.
- Precision@1 0.75 · MRR 0.79
- Corpus: 53 documents, 2,674 chunks (Alberta OHS)
- Hybrid retrieval: pgvector + full-text search
- Adversarial ACL: 8/8 blocked, 0 leaks
- Fail-closed: 5/6 (83%)
- Audit receipts logged (hash-chain fields empty pending re-seal)
- Governed agent extension
- Corpus: 135 documents, 23,684 chunks
- 186 eval cases, 12 categories
- 558 executions, 0 failures
- 153 strict pass · 33 characterization
- 4 system bugs found by eval — all fixed & re-verified
- Enterprise HA or disaster recovery
- Multi-node or distributed deployment
- OIDC/SAML production identity integration
- Third-party penetration testing
- WCAG accessibility compliance
Recent work: governed-incident-agent — generative UI for governed agent actions, built at AI Tinkerers Global Hackathon, May 2026.
Built by Arnaldo Sepulveda
Keystone Applied Intelligence is the independent engineering practice of Arnaldo Sepulveda. The approach comes directly from nearly 13 years at Genesys, building the AI intelligence layer of enterprise contact centers — environments that required production reliability, security controls, and the ability to prove what happened, when, and who authorized it.
That work spanned Knowledge Center retrieval, the chat suite, e-services, and contact intelligence, across regulated and public-sector deployments. The governance patterns Keystone enforces are not new inventions — they are hard-won operational discipline, carried into the LLM era and implemented as architecture.
- Practice Independent engineering practice of Arnaldo Sepulveda · based in Canada
- Background ~13 years at Genesys — AI intelligence layer of enterprise contact centers
- Scope Knowledge Center retrieval · chat suite · e-services · contact intelligence
- Domains Regulated and public-sector deployment experience
- More arnaldosepulveda.com