Frequently asked, fully answered.

Yes. Five layers enforce it: decimal arithmetic with no binary floating point in regulatory fields; lexicographically ordered precursor traversal; canonical JSON serialisation; SHA-256-pinned factor snapshots per reporting period; and private cross-runtime equivalence checks on every reviewed commit.

Concretely: the hosted service records the same trace_id and content_sha256 for identical authorised inputs. Private CI verifies equivalence without distributing the engine, source, binaries, or test corpus.

It sits outside. The M25 calculation engine is pure Rust with zero AI dependencies and zero model calls. The boundary is enforced statically: cargo-deny bans LLM crates from the engine workspace, and CI fails if any AI environment variable appears on the engine host.

AI is confined to four assisting modules: M12/M15 (intake NLP), M60 (narrative generation), M65 (anomaly flagging), and M70 (advisory). None of them writes regulatory numbers. Every AI-proposed change to M20/M25/M40 follows the AI → human → code update gate, with three audit logs (AI Call Log, AI-Assisted Decision Log, AI Override Log) preserved in M65 for the full retention period required by the AI Act.

All six Annex II categories, with the §G precursor chain validated end-to-end (SMR H₂ → DRI → EAF → ferroalloys → alloy steel):

• Cement (§3.3–§3.4): clinker production with §B.9 default-EF + CKD, then clinker-to-cement roll-up.
• Hydrogen (§3.6): SMR, electrolysis (route-aware), chlor-alkali co-product allocation.
• Fertilisers (§3.7–§3.10): NH₃, HNO₃ (N₂O abatement-aware), urea (CO₂ uptake netting), NPK blends.
• Ferroalloys (§3.12): FeSi, FeMn, SiMn, Si, FeCr, FeNi via IPCC §4.3 Tier 1/2 paths plus CH₄.
• Iron & steel (§3.13–§3.16): DRI-EAF, crude steel, alloy-steel composition rollup.
• Aluminium (§3.17): Hall-Héroult anode + PFC + §D electricity scope.

573 in-scope CN codes from the Commission's CBAM Self-Assessment Tool v1.1 (28 March 2025). They live as a tamper-detected JSON fixture (cbam_cn_codes_v1_1.json), SHA-256 pinned inside the FactorSnapshot.

The dispatcher resolves any CN code to its sector engine, canonical precursor list, and valid production routes. Spaces in CN codes are rejected: pass the 8-digit form (e.g. "25232900", not "2523 29 00").

For transitional QReports only, the fastcbam-portal-export crate bundles XSD v23.00 plus official samples. Output passes the transitional portal schema validation (43 rules, 33 conditions, 9 warnings) and ships as a deterministic ZIP. That schema is not the definitive 2026 annual-declaration format.

For 2026, FastCBAM prepares and validates an Article 6 dossier and evidence pack. The Commission has not published the Article 6(6) entry format/workflow, so FastCBAM does not generate or file an official Registry payload.

A daily xsd-watch GitHub Action content-hashes Commission Registry documents and monitors adopted-act links, opening a labelled issue within roughly 24 hours of a change. You hear about a Definitive Period schema or legal-source update before stale mappings reach a declaration.

The engine emits a structured calculation trace per M65: every numeric field carries a trace_id tied to a specific equation, every input is anchored to its source row, every factor is identified by its snapshot SHA-256.

A verifier rerun on a fresh engine host produces a byte-identical trace: the trace_id stays invariant, only engine_artifact metadata changes between placeholder and release builds. Placeholder traces are watermarked and rejected; only signed release artifacts produce verifier-signable output.

A token is one engine call: one sector calculation, one CN lookup, one trace assembly. The dispatcher counts as one token regardless of how many precursors it walks.

• Developer (€0): 500 tokens/month, test-mode (watermarked) traces.
• Starter (€49): 10,000 tokens/month, verifier-signable. Top-ups: €19 / 5,000 tokens.
• Pro (€299): 100,000 tokens/month, multi-installation. Top-ups: €99 / 50,000 tokens, 90-day rollover.
• Enterprise (custom): volume tokens, dedicated capacity, annual commit discounts.

Top-up packs never expire on annual plans. Overages on monthly plans draw from your top-up balance first; if exhausted, requests return HTTP 402 with a clear error code so you can route around them.

No. Calculation source, binaries, WASM, the data model, and deployment artifacts remain proprietary and are not distributed.

Enterprise customers use managed private service capacity with the same authenticated audit and verification controls.

Yes, through the authenticated hosted Model Context Protocol endpoint (spec 2025-11-25). Approved clients receive only the documented tool contract and results.

The gateway exchanges the MCP token for a distinct API token. The model never receives or executes the proprietary calculation engine.

FastCBAM implements the adopted 2026 calculation, customs, verification, certificate, evidence, and annual-draft controls. It produces a deterministic preparation dossier and evidence pack; it does not claim direct filing, accredited verification, or Registry acceptance.

The Article 6(6) declaration-format/submission act, Article 9(5) carbon-price-conversion act, and official annual Registry entry fields/schema remain external blockers. The daily publication watcher content-hashes Registry documents and tracks adopted-act links; any new interface must be mapped and regression-tested before the product claim changes.