Application scope.
Declared contracts.

The five-point product explanation

1. 01The agent declares. Schemaxis marshals the data.

   In the strict declared-work interface, the agent never runs code or directly handles source data. It declares where the data comes from or how it is generated, which operations it passes through, and how it is output. Schemaxis marshals immutable input captures, sealed execution and outputs retained by digest.

   This describes who operates on the inputs: no agent-supplied arbitrary scripts, shell or direct source-filesystem manipulation. The agent can receive bounded observations and receipt content; this does not promise that data is hidden from the model. Sealed container execution requires an explicitly configured, qualified backend. Native applications execute trusted runtime code. The historical local MCP demonstration alone does not establish that isolation.

2. 02The plan is checked before anything executes.

   Admission, the declared schema, task scope and budget reservation are checked before execution. A request outside its authority is refused before a native job can run. Planning and inspection can run without launching the applications; native result verification is a separate step that reports the checks actually performed. In the retained MCP demonstration, a NumPy request under a SymPy-only scope returned SCOPE_EXCEEDED. Calls stopped at planning: zero native execution, all four prior NumPy output digests unchanged, and no successful current invocation to claim.

   Historical prepared-recipe local MCP demonstration, core 5cfe1b0. It is separate from both the comparative study and the hosted container-isolation proof.

3. 03Smaller models failed alone, then produced passing artifacts.

   Haiku 4.5: 22/110 without → 110/110 with Schemaxis; Sonnet 4.6: 22/110 without → 110/110 with Schemaxis; GPT-5.6 Luna: 68/110 without → 110/110 with Schemaxis. Haiku 4.5’s native initial output had 32/32 images rejected, while its retained transcript called the result “production-ready”. The Schemaxis artifacts passed the required checks. The core supplies the verification state and receipt instead of relying on the agent’s success sentence. This records a misleading claim and changed artifact outcomes; it does not measure a general reduction in false-reporting propensity.

   29 September 2026: one authoring conversation per model and method, older model versions, 110 checks across an initial task and revision on small, purpose-built serial ParaView fixtures. Checks are not independent tasks. Some historical Schemaxis runs inspected implementation details or used helper code; one revision wrapper was broken despite passing artifacts. These are artifact outcomes, not qualification of the new strict no-shell authoring interface. The Opus native control was excluded after provider substitution.

4. 04Reuse a supported recipe with varied parameters and a new receipt.

   A supported declared recipe can be repeated with varied authorised inputs and parameters; each execution produces its own receipt. The reusable document and bounded parameter contract are the mechanism, not a measured advantage for junior staff. Anyone using the supported, configured environment and authorised inputs can repeat it. Compatible runtimes, scope and checks still apply; the record preserves honest failure and unknown states.

   The downloadable two-case SymPy example checks local-core binding and host planning only: no native execution or new receipt was created by those preflight checks, and no hosted file-template endpoint is implied.

5. 05Keep the frontier tradeoff and the cheaper-model result together.

   Frontier models passed either way in the retained paired studies, and Schemaxis was slower.

   GPT-5.6 Luna with Schemaxis passed all 110 checks at about one tenth of Astra’s native historical scored API cost (US$0.0815 versus US$0.8828); n=1 conversation each, older versions and 29 September 2026 prices. This is not current pricing or a total compute/support-cost estimate.

Recorded scope refusal ↗ Study artifacts and limits ↗