@metaharness/oo-agents

The agent is a class. The model acts by writing code — inside a Rust/WASM sandbox.

A TypeScript + Rust/wasm32 clone of NOOA (NVIDIA-NeMo/labs-OO-Agents, arXiv:2607.20709): fields are state, methods are capabilities, doc strings are prompts, schemas are typed contracts, and an agentic method has no body — the runtime hands it to a model driver that emits code cells executed against the live object. See ADR-242.

import { Agent, agentic, Runtime, ScriptedDriver } from '@metaharness/oo-agents';

class SupportAgent extends Agent {
  static doc = 'You are a support agent.';

  // State lives on the object.
  orders: Record<string, Order> = { /* … */ };

  // Ordinary method. Just TypeScript — callable from sandbox cells as
  // self.isRefundEligible(id).
  isRefundEligible(orderId: string): boolean {
    const o = this.orders[orderId];
    return o.delivered && o.daysSinceDelivery <= 30;
  }

  // Agentic method: the runtime hands this to a model driver.
  triage = agentic({
    doc: 'Create a typed support ticket.',
    params: { message: { type: 'string' }, orderId: { type: 'string' } },
    returns: {
      type: 'object',
      properties: { orderId: { type: 'string' }, refund: { type: 'boolean' }, note: { type: 'string' } },
      required: ['orderId', 'refund', 'note'],
    },
  });
}

The Rust/WASM sandbox is the point

NOOA sandboxes Python cells with guard lists in a worker process. This clone gets isolation by construction: cells are written in cellscript — a small deterministic imperative language (let/if/while/for, arrays, objects, strings; self.method(...)/self.field host bridge; return_result(v); print) — interpreted by a ~1k-line Rust VM compiled to wasm32-unknown-unknown (~180 KB, no wasm-bindgen, no dependencies):

• No ambient authority. The language has no filesystem, network, clock, randomness, or FFI. The ONE window to the world is a single JSON host import answered from the bound agent object — every state read and capability call crosses an inspectable, loggable boundary.
• Fuel-bounded. A runaway cell traps deterministically (fuel exhausted) instead of hanging the harness.
• REPL-faithful. Last-expression value, explicit return, namespace persistence across cells, and return_result(v) as the ExecutionSignal — the semantics of NOOA's cell_core.py.

Typed contracts with auto-retry

TS erases types at runtime, so contracts are explicit Schema values (NOOA reads Python annotations). Validation runs where NOOA's does — on return_result — and a violation is fed back to the driver verbatim as the retry prompt (typed contract violated: $.refund: expected boolean, got string; expected { orderId: string, refund: boolean, note: string }).

Drivers

ModelDriver is the only seam where a model enters. The package ships the deterministic ScriptedDriver (tests/simulation) and renderContext (the canonical prompt rendering). Real LLM drivers are host wiring — the kernel owns model routing — by design.

Build & test

npm run build:wasm   # cargo build crate/ → wasm/ooa_cell_vm.wasm
npm run build && npm test
cd crate && cargo test   # VM-level tests, native

Apache-2.0 (upstream NOOA's license).