@zioladev/interop-runtime

Run stateful objectives across independent WebMCP providers.

@zioladev/interop-runtime is a model-agnostic runtime for executing ordered, multi-step trajectories across independent provider surfaces. It carries authoritative outputs from one step into subsequent steps with provenance, resolves provider transitions through a runtime-independent host boundary, and determines completion from explicit terminal requirements — not from model narration or from "the loop finished."

The runtime separates planning from execution: model adapters decide, a common execution bridge acts, and observed runtime evidence — never model memory — becomes the authoritative trajectory state. No provider-specific orchestration is required. The same trajectory engine runs against a deterministic in-process reference runtime or a browser host implementing native document.modelContext (WebMCP), byte-identical spec on both.

Quickstart

import{runMultiProviderTrajectory,evaluateMultiProviderTrajectory,makeReferenceSurfaceResolver,makeScriptedTrajectoryAdapter,}from'@zioladev/interop-runtime';// 1. A trajectory: an ordered objective across independent providers, with the terminal// requirements that define "done" — state-changing commits and/or required non-mutating work.constspec={trajectoryId: 'cafe-then-gallery',text: 'Order a latte at the cafe, then check a color against the gallery palette.',providers: [cafe,gallery],// ProviderRef[] — id + independent originsteps: [{stepId: 's1',seq: 1,provider: cafe,intent: 'order_latte',allowedTools: ['read_menu','order_latte'],commitRequired: true,requiredForTerminal: true},{stepId: 's2',seq: 2,provider: gallery,intent: 'check_design_drift',allowedTools: ['check_design_drift'],dependsOn: ['s1'],requiredForTerminal: true},],};// 2. A surface resolver: HOW the runtime reaches each provider. Deterministic in-process here; swap// makeBrowserSurfaceResolver(host, defs) to run the SAME spec against native WebMCP in a browser.constresolver=makeReferenceSurfaceResolver(providerImpls);// 3. Run it: resolve provider → prepare surface → discover tools → decide (adapter) → execute →// carry resulting state with provenance → transition provider → continue → judge terminal.constobservation=awaitrunMultiProviderTrajectory(resolver,spec,adapter);constresult=evaluateMultiProviderTrajectory(observation,spec);result.terminalAttained;// was the required world-state actually reached?result.trajectoryConformance;// PASS / FAILresult.routeKey;// the executed route across providersobservation.carried;// lineage-bearing carried state (built from evidence, not memory)observation.records;// per-step execution evidence

adapter is any ModelConsumerAdapter — a deterministic makeScriptedTrajectoryAdapter(...) for reproducible runs, or a live model adapter (makeClaudeAdapter/makeGptAdapter/makeGeminiAdapter). The engine owns sequencing, state, and terminal judgment regardless of which one decides.

Runtime primitives

These are the things the runtime is, not tests of it:

• Ordering. The trajectory owns sequencing above individual execution steps. A step may declare dependsOn predecessors; the engine runs the objective, not a flat list of calls.
• Portable, authoritative state. A step publishes outputs into carried state, lifted from its execution evidence; a later step's requiredInputs bind to that lineage. The model's claim about what it carried is only a claim — the runtime verifies it against observed evidence (D36).
• Terminal semantics. Completing the loop is not completing the objective. Terminal state is a frozen predicate: every commitRequired leg must have committed and every requiredForTerminal leg must have been attained — including required non-mutating work (D43), so a mandatory final read/verification counts toward "done" without being mislabeled a commit.
• Runtime-independent host boundary. Providers are reached through a SurfaceResolver / BrowserHost port the runtime defines and a host implements — navigate, discover, execute one call. The engine imports nothing from the host, so it stays authoritative for sequencing, state, and terminal judgment while the arms and legs change (in-process reference ⇄ native WebMCP browser).

Runtime invariants

Architectural guarantees the runtime holds, by construction:

• The trajectory sits above the steps, never in place of them. Every step keeps its own per-decision attribution; the trajectory layer only adds ordering, state-propagation, and terminal judgment on top.
• Model memory is never authoritative trajectory state. Carried state is built from observed execution evidence; a binding is a claim, verified against it, never trusted.
• Completing the loop is not completing the trajectory. Terminal state comes from the frozen predicate — did the required commits and required steps actually attain? — not from "all steps ran."
• A consumer/orchestration failure is never a provider failure. The provider grade is computed only from provider-owned layers; sequencing faults land on trajectory_orchestration, a model's clean decline of a required commit lands on the model — never on the provider.
• A different valid path is not a failure. Two adapters taking different valid routes to the same allowable terminal state, with state preserved and invariants satisfied, both conform.

Optional execution control (before the provider call)

The runtime can consult an external, opaque execution-control authority before a state-changing execution reaches a provider — structurally compatible with @zioladev/execution-control, with no hard dependency (the port is re-declared here).

constobservation=awaitrunMultiProviderTrajectory(resolver,spec,adapter,{executionControl: {mode: 'required',provider: myAuthority},// myAuthority.evaluate(candidate) → 'allow' | 'block' | 'indeterminate'});

• mode: 'off' — existing behavior; no evaluation, no control claim.
• mode: 'required' — every state-changing decision must receive allow before the common bridge may call the provider tool. allow proceeds; block / indeterminate / missing-provider / throw / timeout all mean the provider is never called (fail closed). Non-state-changing tools bypass the seam entirely.

The runtime builds the candidate from what it already holds and forwards it unchanged — it never derives, interprets, or inspects the disposition or the arguments. A stopped step is recorded as stopped_by_execution_control in a StepResults.executionControl observation kept distinct from the provider ExecutionResult, and it is not a fault: the provider grade is untouched (the provider was never called), and whether the objective is attained is left to the terminal semantics. In one property: a prompt-injected or over-agentic model can select the tool and build valid arguments — and still lack authority to cross the provider boundary. Model decision, provider conformance, and trajectory qualification each ≠ execution permission; only an allow grants it.

Evidence & interoperability analysis

Every run produces a versioned, machine-readable trajectory report (provider-conformance-report/2) plus structured evidence you can use to identify step failures, orchestration faults, provider faults, path differences, and cross-model divergence — each failure attributed to the layer that caused it (the model's decision, the orchestration, the provider, or the runtime).

Testing interoperability across model consumers

Because the runtime is model-agnostic, running the same frozen trajectory through several adapters turns cross-model evaluation into a capability of the runtime — do Claude, GPT, and Gemini each reach the same allowable terminal state, and where do they diverge?

import{runCrossModelTrajectory,compareCrossModelTrajectory,renderCrossModelArtifact,}from'@zioladev/interop-runtime';constresults=awaitrunCrossModelTrajectory(providers,frozenSpec,[claude,gpt,gemini]);constcomparison=compareCrossModelTrajectory(frozenSpec.trajectoryId,results);console.log(renderCrossModelArtifact(results,comparison));

Trajectory: cafe → bakery
anthropic-claude Path: cafe/commit:place_order -> bakery/commit:add_pastry Terminal: attained Conformant: PASS
openai-gpt Path: cafe/inspect:lookup -> cafe/commit -> bakery/commit Terminal: attained Conformant: PASS
google-gemini Path: cafe/commit -> bakery/(deferred) Terminal: not attained Conformant: FAIL Attribution: model_tool_selection
Provider: PASS
Cross-model: path difference: yes · terminal difference: yes · conformance difference: yes

The reference lane is deterministic (in-process ReferenceRuntime). The live cross-model acceptance runs the real model APIs from the cloud — see .github/workflows/crossmodel-live.yml and scripts/crossmodel-live.ts. A makeBrowserSurfaceResolver lane drives the identical spec on native WebMCP through a privileged browser host (the runtime is the brain; the host is the arms and legs).

Relationship to @zioladev/provider-conformance

Where @zioladev/provider-conformance (Phase II) measures a single decision against one provider, this package (Phase III) executes a trajectory across many and emits evidence about it.

It takes no dependency on that package: the small, stable single-decision primitives it needs (attribution engine, execution bridge, reference runtime, model adapters, core types) are re-authored here so both packages remain independently functional. The duplicated pieces are tracked in DUPLICATION-LEDGER.md; a shared-layer extraction is deferred until the interfaces have survived real runs, rather than minting a common package prematurely.

Scripts

npm run typecheck # tsc --noEmit
npm test # node --experimental-strip-types --test (Node >= 22.6)
npm run build # emit dist/ (ESM + .d.ts)

License

Apache-2.0. Clean-room — imports nothing from any proprietary source; a test asserts it. See NOTICE.