---
title: Nexus — the standard way N1 builds clinical AI products
---

# Nexus — the standard way N1 builds clinical AI products

> _Nexus defines one composition model for clinical AI products: authored files, `n1r.core`, Pinax, the Nexus runtime, clinical reasoning artifacts, and Composer._

N1 currently has workflow-specific clinical AI paths where product logic, data access, token handling, model routing, telemetry, and output shaping are assembled per workflow. Nexus defines a standard product structure for those concerns.

| What | Count | Detail |
|---|---|---|
| Standard product model | 1 | Nexus is the standard way N1 builds clinical AI products |
| Main runtime library | 1 | `n1r.core` owns pack loading, tokens, models, observability, run bounds, and artifact emission |
| Capability layer | 1 | Pinax exposes governed capabilities under the caller's scope |
| Durable reasoning unit | 1 | Clinical reasoning artifacts are the durable platform record |
| Surface layer | 1 | Composer turns artifacts into narrative, chart, card, UI, and API surfaces |
## The components

| Component | What it is | Status |
|---|---|---|
| **Nexus** | The standard way N1 builds clinical AI products. Most engineers author files. The runtime owns the rest. | Being defined |
| **`n1r.core`** | The N1-owned Python runtime API. Loads packs, validates them, acquires and refreshes OAuth2 tokens, resolves models, emits PHI-safe observability, bounds runs, and emits artifacts. | Specifying now |
| **Pinax** | The deterministic capability layer in front of patient-context and other governed tools. It uses the token and runtime context it is handed. It does not mint auth. | Specifying now |
| **Clinical reasoning artifacts** | The durable structured output of reasoning. They hold facts, evidence, interpretation, uncertainty, and lineage-friendly references. | Specifying now |
| **Composer** | The layer that turns artifacts into human-facing surfaces such as cards, charts, reports, chat payloads, and API outputs. | Specifying now |
| **Baseline trust rails** | Auth, PHI handling, telemetry rules, eval hooks, guardrails, audit, and bounded runtime behavior. These are baseline rails, not the platform thesis. | Specifying now |
## The one-line boundary split

`n1r.core` owns runtime mechanics. Pinax owns governed capability access. `api-backend` owns policy enforcement. Composer owns presentation. Artifacts own the durable reasoning record.

## Pages in this deck


| Page | Title | What it covers |
|---|---|---|
| [01](/presentations/nexus/01-why-nexus/) | [Why Nexus exists](/presentations/nexus/01-why-nexus/) | N1 uses workflow-specific clinical AI paths today. Nexus defines one standard way to build clinical AI products. |
| [02](/presentations/nexus/02-how-products-are-authored/) | [How products are authored](/presentations/nexus/02-how-products-are-authored/) | Most engineers should build Nexus products by writing validated files, not by editing framework internals. |
| [03](/presentations/nexus/03-n1r-core/) | [`n1r.core` — what the runtime owns](/presentations/nexus/03-n1r-core/) | `n1r.core` is the N1-owned runtime surface. It hides substrate details and owns the cross-cutting mechanics every Nexus product needs. |
| [04](/presentations/nexus/04-pinax/) | [Pinax — governed capability access](/presentations/nexus/04-pinax/) | Pinax is the deterministic capability layer. It exposes governed tools through a small reviewed surface. |
| [05](/presentations/nexus/05-clinical-reasoning-artifacts/) | [Clinical reasoning artifacts — the durable spine](/presentations/nexus/05-clinical-reasoning-artifacts/) | Nexus uses clinical reasoning artifacts as the durable platform record. |
| [06](/presentations/nexus/06-composer/) | [Composer — turning artifacts into surfaces](/presentations/nexus/06-composer/) | Composer is the layer that turns durable artifacts into the human-facing things product teams actually ship. |
| [07](/presentations/nexus/07-runtime-and-lineage/) | [Runtime and lineage](/presentations/nexus/07-runtime-and-lineage/) | The Nexus runtime should make product execution bounded, observable, and easy to audit without leaking sensitive content. |
| [08](/presentations/nexus/08-baseline-trust-rails/) | [Baseline trust rails](/presentations/nexus/08-baseline-trust-rails/) | Auth, PHI handling, telemetry rules, eval hooks, guardrails, and audit are baseline rails. They are not the product thesis, but they must be present from day one. |
| [09](/presentations/nexus/09-proofs-we-already-have/) | [Proofs we already have](/presentations/nexus/09-proofs-we-already-have/) | Several Nexus design elements already exist in working or audited form. |
| [11](/presentations/nexus/11-decisions/) | [Decisions still requiring explicit ratification](/presentations/nexus/11-decisions/) | These items require explicit owner-level confirmation. |