Nexus Tech Tree — Record

Captured for the first Nexus build on 2026-06-13. 8 eras · 31 nodes.

Eras

id	name	tagline
ERA-0	Name the platform	Ratify the names, the boundary split, and the first public contracts so everyone is building the same thing.
ERA-1	Author the product	Most engineers build products by authored files, not framework Python.
ERA-2	Wire the core	`n1r.core` owns tokens, model routing, observability, bounds, and runtime execution.
ERA-3	Open the library	Pinax exposes governed capabilities and patient-context reads through one shaped door.
ERA-4	Make reasoning durable	Clinical reasoning artifacts and lineage become the durable spine.
ERA-5	Compose surfaces	Composer turns artifacts into product surfaces.
ERA-6	Run products reliably	Nexus runtime makes execution bounded, visible, and auditable.
ERA-7	Retire draft docs	Older draft platform docs are retired from the active architecture set.

Relationship tree

An edge runs prereq -> node. Nodes with no prereqs in an era are frontier nodes you can start now.

ERA-0

nexus-brief
supersession-adr
n1r-core-api

ERA-1

authoring-pack <- nexus-brief, n1r-core-api
pack-validator <- authoring-pack
definition-store <- authoring-pack
definition-document-contract <- definition-store
definition-versioning <- definition-document-contract
clinician-agent-authoring-surface <- definition-document-contract

ERA-2

runtime-context <- n1r-core-api
token-lifecycle <- runtime-context
model-resolver <- runtime-context
llm-observability <- runtime-context, model-resolver
hard-run-bounds <- runtime-context

ERA-3

pinax-service <- token-lifecycle
pinax-capability-api <- pinax-service
patient-bound-session <- pinax-capability-api
shaped-capability-outputs <- pinax-capability-api

ERA-4

clinical-artifact-contract <- n1r-core-api
artifact-lineage <- clinical-artifact-contract, llm-observability

ERA-5

composer-service <- clinical-artifact-contract
surface-contracts <- composer-service, artifact-lineage
ag-ui-artifact-panel <- composer-service, artifact-lineage

ERA-6

nexus-runtime-service <- hard-run-bounds, artifact-lineage, pinax-service
baseline-trust-rails <- nexus-runtime-service, llm-observability
react-workflow-builder <- definition-versioning, clinician-agent-authoring-surface
template-agent-library <- definition-versioning
platform-ai-chat <- nexus-runtime-service, pinax-service, ag-ui-artifact-panel
chat-session-store <- platform-ai-chat, artifact-lineage

ERA-7

retirement-map <- supersession-adr, nexus-runtime-service, composer-service
retired-doc-notices <- retirement-map

Node notes

Node	Era	Purpose	Required behavior	Excluded form
`nexus-brief`	ERA-0	Define one standard product model	Define Nexus as the standard way N1 builds clinical AI products	Keep old and new platform names active without a supersession record
`supersession-adr`	ERA-0	Record the current platform naming set	Publish one accepted ADR that maps older platform documents to Nexus replacements	Leave older platform documents without a current supersession record
`n1r-core-api`	ERA-0	Define the current runtime contract	Publish one N1-owned API for pack and definition loading, validation, and bounded runs	Expose substrate objects as the required consumer interface
`authoring-pack`	ERA-1	Define the file-authored contract	Constrain authoring to validated files and normalized runtime fields	Allow unsupported workflow-local hooks or hidden runtime code
`pack-validator`	ERA-1	Prevent invalid authored input from reaching runtime	Fail invalid packs before execution	Continue into runtime after blocking validation failures
`definition-store`	ERA-1	Store runtime definitions in a document-native source	Use DocumentDB as the primary store for agents, skills, teams, workflows, templates, and versions	Use Postgres JSONB as the primary runtime-definition source
`definition-document-contract`	ERA-1	Standardize stored definition shape	Use stable definition and immutable version documents	Store runtime definitions without a shared contract
`definition-versioning`	ERA-1	Make activation and rollback explicit	Use immutable versions plus current-version pointers	Mutate historical versions in place
`clinician-agent-authoring-surface`	ERA-1	Define clinician editing boundaries	Expose constrained clinician-editable fields only	Expose auth logic, provider config, or arbitrary code fields
`runtime-context`	ERA-2	Define the bound run/session context	Carry run ID, principal, subject user, narrowing record IDs, and timeout configuration	Treat patient or auth scope as optional runtime values
`token-lifecycle`	ERA-2	Define one runtime token boundary	`n1r.core` acquires and refreshes the token centrally	Move token minting into capability or pack code
`model-resolver`	ERA-2	Define one model-resolution boundary	Resolve by registry ID and use provider-native routes	Use one generic adapter path for all provider behavior
`llm-observability`	ERA-2	Centralize attribution, cost, and safe telemetry	Emit PHI-safe spans with run, pack, caller, and model metadata	Emit raw prompts, completions, or PHI-rich payloads in default logs
`hard-run-bounds`	ERA-2	Enforce mandatory execution timeouts	Wrap async execution in hard wall-clock limits and cancellation	Use `tool_call_limit` as the sole execution bound
`pinax-service`	ERA-3	Define governed capability access	Use discovery-first deterministic shaped outputs	Mirror backend routes directly as tools
`pinax-capability-api`	ERA-3	Define the capability contract	Specify deterministic capability contracts with shaped outputs	Allow each capability to define its own envelope and auth
`patient-bound-session`	ERA-3	Restrict patient scope to session	Bind subject context once in runtime/session state	Expose `patient_id` as a model-supplied tool argument
`shaped-capability-outputs`	ERA-3	Shape capability response modes	Return `result`, `clarify`, `narrow`, `absent`, or `need-input`	Return raw nested dicts or bare empty lists
`clinical-artifact-contract`	ERA-4	Define the durable reasoning record	Use artifacts as the primary platform record	Use the final report as the primary platform record
`artifact-lineage`	ERA-4	Define the artifact lineage record	Link artifacts back to runs, versions, sources, and runtime metadata	Use model-authored lineage fields or define lineage as exact replay
`composer-service`	ERA-5	Define the surface-composition layer	Build narratives, charts, cards, and report sections from artifacts	Add primary reasoning to the surface layer
`ag-ui-artifact-panel`	ERA-5	Define live artifact-panel events	Use typed AG-UI panel and widget contracts with artifact/lineage links	Send arbitrary renderer code or untyped payloads to the browser
`surface-contracts`	ERA-5	Define stable downstream shapes	Publish clear output contracts for narratives, charts, and cards	Require every consumer to parse one combined report blob
`nexus-runtime-service`	ERA-6	Define runtime execution behavior	Use bounded agent, team, and workflow runs, safe status, explicit retries, active-version selection, and durable lineage	Leave runtime state and failure reporting implicit
`baseline-trust-rails`	ERA-6	Enforce baseline platform rules	Enforce auth, PHI-safe telemetry, eval hooks, and fail-closed behavior	Omit baseline rails or define them as the only platform thesis
`react-workflow-builder`	ERA-6	Define the React app authoring surface	Show visible definitions, allow constrained editing, and use React Flow	Use Svelte or hide existing definitions
`template-agent-library`	ERA-6	Reuse platform specialist agents safely	Copy platform templates into clinic or clinician control before edits	Edit platform templates in place
`platform-ai-chat`	ERA-6	Define the platform-wide chat surface	Run chat through `n1r.core` with Pinax and Artifact panel support	Create a separate ungoverned runtime path for chat
`chat-session-store`	ERA-6	Preserve durable chat linkage	Store chat session, artifact, and event references in DocumentDB	Depend on raw logs as the only chat record
`retirement-map`	ERA-7	Define the mapping from retired drafts	Record how older draft platform assumptions map into active Nexus specs	Leave older draft architecture in the active spec surface
`retired-doc-notices`	ERA-7	Mark old files as retired	Explicitly retire older draft files from the active spec surface	Leave retired draft architecture without retirement markers