SDK API reference

@openprose/reactor is the Reactor layer of one system, made programmable. OpenProse is the foundation -- the paradigm where you declare the outcomes you want kept true, as Markdown contracts. The CLI is one driver of this SDK; so is the DevTools replay viewer. This reference documents the surface both of them sit on, so you can host a reactor from your own code.

One call takes a directory of .prose.md contracts all the way to a booted, reconciling reactor and hands back one typed handle:

import { reactor } from "@openprose/reactor";

// Compile ./my-project, assemble a durable reactor over ./state, boot to a
// fixpoint (cold nodes render once; warm nodes memo-skip), return a live handle.
const { reactor: r } = await reactor("./my-project", { directory: "./state" });

console.log(r.view.cost);     // { fresh, reused, byCause, byNode } -- the hero metric
await r.ingest("source", { data: { "in.txt": textFile("hello") } });

That is the front door. Everything deeper is reachable, but it is deliberately one rung down. This page is the map.

The six reasoned entrypoints

The package ships six entrypoints (plus ./package.json). This is not arbitrary surface area: each split exists for a reason an agent can reason about before importing. The curated front door is .; the rest are isolation seams you reach for only when you need what they isolate.

Read these pages in order

Install and prerequisites

The SDK is a published npm package. Install it per-project alongside its optional peers (you only need the peers when you actually render against a model):

npm install @openprose/reactor
# When you render against @openai/agents (the live run path):
npm install @openai/agents zod

• Version: @openprose/reactor@0.3.0. (The CLI is @openprose/reactor-cli@0.2.0 and DevTools is @openprose/reactor-devtools@0.2.0; they version independently. The OpenProse language and skill version separately again -- do not attach 0.3.0 to the language.)
• Node: >=20.0.0.
• Peers (optional): @openai/agents@^0.11.6 and zod@^4.0.0. They are marked optional in peerDependenciesMeta: the keyless inspection/replay surface never loads them. You pull them by importing /agents, /run, or the live render path.

What's built, and what isn't

In the spirit of the receipts, the honest status. For coding agents onboarding on behalf of a user, this block is the trust mechanism: the SDK does not pretend.

Built and runnable. The render atom, the content-addressed world-model store (with the published-truth / private-workspace split), the compiled canonicalizer with facets, Forme's wiring with diagnostics and acyclicity, postcondition-gated commits with no judge step, the receipt ledger with chain verification, and composition pins are implemented and exercised by a test suite that runs offline -- no model calls in the commit gate. The reconciler's surprise property is enforced as a tested invariant: when an input fingerprint doesn't move, the render body provably never runs.

Deliberately not yet here.

• No benchmark or dollar numbers. We are not going to pretend a structural invariant is a measured speedup. Designing honest long-horizon benchmarks is the help we most want -- these pages assert no performance figure.
• The signer is an explicit null state. In v1, signed means tamper-evident at the meaning layer and chain-consistent -- not yet a cryptographic byte hash. The signature is an honest null ({ scheme: "none", null_reason: "no-signer-adapter-configured" }). The reserved SignerPort seam means the crypto milestone is a backend swap, not a reshape.
• No timestamp or actor on receipts yet. The chain is content-addressed and ordered; wall-clock attribution is named, not shipped.
• The fixpoint is specified and deferred. The topology as a responsibility (an epoch driver layered over the fixed-topology handle) is designed -- the handle already exposes topology + drain + onReceipt for exactly that loop -- but the driver itself is a reserved, forward-only seam, declared and not built.
• Facet inference and ledger compaction are named roadmap, not shipped.

These caveats are surfaced inline where they bite, too: the reconciler and receipts for what "signed" means in v1, world-model and fingerprints for the signer caveat, and CLI configuration for the deferred knobs.

Where to go next

The conversation always ends. The responsibility shouldn't have to.