Jeffrey V. Johnson, Ph.D.

Host Capability Substrate : typed capability and evidence contracts

TypeScript · Zod · JSON Schema · GitHub Actions · Public source

• Built typed capability and evidence contracts with generated JSON Schemas and automated checks.
• Modeled host capabilities, operations, execution contexts, policy decisions, provenance-typed evidence, approvals, leases, audit chains, and scoped authorization grants.
• Defined architecture boundaries and a governance charter, with CI checks for policy, imports, secrets, and schema drift.
• The public repository demonstrates the typed model and source boundaries, not universal host-level runtime enforcement.

Agentic Architecture Audit : specification and drift checks for agent-operated codebases

Specification · JSON Schema · Python tooling · Public source

• Authored a two-stage audit-spec that keeps evidence collection separate from judgment.
• Defined a structured review rubric, JSON output contracts, and a prioritization model based on severity, confidence, and weight.
• Built a Python drift linter that binds derived documentation to specification content, with negative self-tests in pre-commit and CI.

Governance and agent-control architecture : federated authority for agent-assisted work

An anonymized private case study · OpenTofu · OPA/Rego · TypeScript · Cloudflare · Hetzner · Proxmox

• Designed a multi-repository architecture that separates human decision rights, agent permissions, identity and authorization, infrastructure enforcement, runtime admission, and repository-local authority.
• Modeled agent authority as the intersection of mandate, available capability, and credential reach, with structured, secret-free handbacks for human judgment or privileged work.
• Implemented selected controls including OPA/conftest plan rules, repository governance as code, Zero Trust infrastructure, and scheduled drift checks. The plan gate is workflow-level enforcement; it is not proven as a required status check across every repository.
• The July 15, 2026 review found selected controls operational; runtime admission was source-tested rather than deployed across the organization. This is a single-operator case study, not an enterprise-adoption claim.

Agentic-Coding Evaluation Lab : fail-closed evaluation evidence

Public methodology and verification prototype · Python · Quarto · JSON contracts

• Built and published a model-evaluation methodology and verification prototype that preserves evidence and withholds a recommendation when scientific prerequisites are incomplete.
• Built a draft evidence contract and a separate verifier that recalculates a synthetic NOT_EVALUABLE outcome and rejects missing, inconsistent, or altered evidence.
• Current evidence covers framework behavior and synthetic conformance, not a powered real-model result or promotion recommendation.

Budget Triage : financial evidence workbench

Public employer-facing source snapshot · active development private · Bun · TypeScript · Hono · PostgreSQL · not deployed

• Built a financial evidence workbench for statements, receipts, and connected-account data with deterministic-first processing and human review.
• Implemented exact monetary arithmetic, tenant-scoped atomic persistence, append-only decision records, authentication, Plaid, Infisical, and OpenTelemetry.
• Implemented context-specific data relationships with explicit transitions, tenant checks, database row locks, and stale-update protection.
• Diagnosed an authentication test that failed on database reuse, tracing the interaction between rollback and persistent audit records.
• Built a synthetic known-answer and service-observation harness. The July 15, 2026 review recorded 6 passing and 9 pending assertions, an incomplete and uncertified result.
• Published a sanitized, MIT-licensed source snapshot for employer review on 2026-07-21. Active development remains private; publication is not deployment or an open contribution surface. Explore the public source.

ScopeCam : native Android UVC camera application

Private Android · Kotlin · Jetpack Compose · C++20 · JNI/NDK · USB/UVC

• Built a multi-module Android microscope application spanning Compose UI, Kotlin orchestration, a native C++ camera engine, USB lifecycle, persistence, diagnostics, and physical-device verification.
• Diagnosed a camera-replug ANR across the JVM/native teardown boundary and implemented a device-verified recovery with the remaining leak tradeoff documented.
• Delivered a signed client alpha in June 2026; the private product is not broadly released.
• Corrected a CI dependency gap that could report success after an upstream failure skipped the actual checks. Source change reviewed in September 2026.

Dicee : representative delivered software

Rust · WebAssembly · SvelteKit · Cloudflare Durable Objects · WebSockets

• Built and deployed a family multiplayer game with a Rust-to-WebAssembly rules engine, real-time state through Cloudflare Durable Objects and WebSockets, and a SvelteKit client.
• Public source and a live deployment demonstrate end-to-end delivery; traffic, performance, bundle-size, and current test-count claims remain withheld.

Inspect Scout : reliability correction under review

Submitted a Python correction for provider-error diagnostics lost between spawned workers and the parent process, with regression evidence for the proposed change. I responded to maintainer scope feedback with further validation on September 12, 2026. The PR remains under review, awaiting a reply.