Exemplar Stack

Exemplar is a component stack for contract-driven, observable, human-governed automation in small-business operator workflows. Reeve currently contains first implementations of some stack disciplines, but those disciplines are stack components, not Reeve features.

The integration stance is proactive: safety, routing, anomaly, authority, audit, and smoke controls are wired before a customer-visible failure proves the need. Implementation can phase by maturity, but these controls are part of the gold-standard operating environment.

For an infrastructure-team handoff that explains the operational invariants, composition paths, failure semantics, and capability introduced by the tool suite, read docs/infrastructure-handoff.md. For the workspace inventory that separates core Exemplar tools from supporting, adjacent, research, and non-tool repos, read docs/code-inventory.md.

Component Map

Component	Language	Charter	Primary consumers	ADR
Constrain	Python	Interview and synthesize stack artifacts from problem intent.	Pact, Ledger, Arbiter, Baton	constrain/README.md
Pact	Python	Contract-first decomposition, tests, and agent implementation pipeline.	Reeve, Sentinel, Arbiter	pact/README.md
Reeve	TypeScript	Operator-facing business automation and first integration host.	Operators, Baton, Tessera	reeve/docs/stack-roadmap.md
Baton	Python	Circuit orchestration, adapter control, taint scanning, canary routing.	Reeve, stack-smoke	baton/CLAUDE.md
Ledger	Python	Field classification and obligation registry.	Baton, Reeve, Sentinel	ledger/CLAUDE.md
Arbiter	Python	Access auditing, consistency analysis, blast-radius classification, and trust enforcement.	Baton, Ledger, Sentinel	arbiter/README.md
Sentinel	Python	PACT-key attribution and enforcement severity.	Baton, Reeve	sentinel/design.md
Tessera	Rust	Self-validating executable document and hash-chain evidence format.	Reeve, scram, witness	tessera/README.md
Chronicler	Python	Event collection and story assembly from spans, logs, webhooks, and incidents.	Reeve, Sentinel, Vigil	chronicler/README.md
Stigmergy	Python	Organizational pattern discovery over work artifacts and correlated stories.	Chronicler, Apprentice, operators	stigmergy/README.md
Apprentice	Python	Distill repeated frontier-model tasks into cheaper local models with quality gates.	Reeve, Chronicler, Stigmergy	apprentice/README.md
Signet	Rust	Sovereign credential vault, proof, and agent authority policy.	Reeve, witness, operator identity	signet/README.md
Cartographer	Python	Stack adoption, discovery, and compatibility checks for existing codebases.	Infrastructure team, CI	cartographer/README.md
aegis	TypeScript + Python	Hot-path resource budgets and egress wrappers with golden vectors plus differential fuzzing.	Reeve, Baton	aegis/ADR-001-extraction.md
covenant	TypeScript + Python	Zod-canonical contracts exported to committed JSON Schema for Python consumers.	Reeve, Baton, Ledger, Sentinel	covenant/ADR-001-extraction.md
vigil	Python	Off-path anomaly detection using rolling quantile baselines over stack event streams.	Baton, Reeve dashboard	vigil/ADR-001-extraction.md
scram	Python	Emergency kill switch and read-only/quarantine actions.	Reeve, Baton, witness	scram/ADR-001-extraction.md
witness	TypeScript	Human-in-the-loop decisions and two-person approval.	Reeve, scram	witness/ADR-001-extraction.md

Dependency Shape

Constrain ──synthesizes──> Pact ──contracts/tests──> Reeve

Reeve ──emits events──> Baton ──taint/attribution──> Sentinel
  │                       │
  │                       ├──reads classifications──> Ledger
  │                       └──forwards spans/findings──> Arbiter
  │
  ├──writes audit evidence──> Tessera
  ├──emits stories/events───> Chronicler ──patterns──> Stigmergy
  ├──uses credentials/proofs──> Signet
  ├──feeds repeatable tasks───> Apprentice
  ├──uses hot-path budgets──> aegis
  ├──validates contracts───> covenant
  ├──surfaces anomalies────> vigil
  ├──registers conditions──> scram
  └──routes human review───> witness

Cartographer scans existing systems and drafts Constrain/Pact/Ledger/Arbiter/
Baton/Sentinel artifacts before a component is fully onboarded.

Production-Stability Disciplines

• Budget every hot-path external resource through aegis.
• Validate wire contracts through covenant before cross-component egress; TypeScript Zod contracts are canonical and JSON Schema export drift is a CI failure.
• Use Ledger for data obligations and Arbiter for access/trust/blast-radius findings derived from observed behavior.
• Emit component health through peer APIs rather than a shared health table.
• Correlate raw events into stories through Chronicler before feeding pattern consumers such as Vigil, Stigmergy, and Apprentice.
• Use Cartographer during adoption and CI compatibility checks to discover missing stack artifacts before runtime.
• Keep stack-wide and continuous smoke assertions in the stack-smoke repo.
• Keep Reeve-specific migrations to extracted libraries in Wave 3, after component ADRs and skeletons land.

Current Status

• aegis, covenant, vigil, scram, and witness are standalone public repos with v0.1.0 releases.
• baton, ledger, arbiter, chronicler, stigmergy, cartographer, stack-smoke, and this overview repo are part of the broader Exemplar tooling surface.
• baton-stack is deployed on Fly and participates in live stack-smoke via /api/snapshot and /v1/about.
• Reeve is the first production integration host. It is deployed to staging and production with smoke checks for liveness, readiness, audit-chain shape, stack mode, and registry population.
• The next phase is composition: migrate Reeve to consume the extracted libraries, make Scram dispatchers real, surface Vigil in the operator dashboard, keep continuous smoke running, and promote stack-smoke into a full multi-service scenario.