Changelog
What's shipped and live on the Tax MCP compute API. Contract-affecting changes are versioned in the OpenAPI spec; the live supported envelope is always at tax-capabilities.
First-user loop: readable capabilities, onboarding path, site-wide navigation
2026-07-07
- GET /api/mcp/tax-capabilities is now human-readable in a browser: a scannable HTML view (capability index, per-route syntax examples, jurisdictions, declines & billing, affirmations, not-modeled) rendered from the same source object as the JSON. Machine clients are unaffected — any request without Accept: text/html (or with ?format=json / ?raw=1) gets the unchanged JSON contract.
- An explicit answer to “Can I use this from ChatGPT or Claude?” on the capabilities page: Tax MCP is a deterministic HTTPS API (OpenAPI + a bounded machine MCP transport you can self-integrate with your own key). A hosted one-click ChatGPT/Claude connector is not yet generally available.
- Docs “Start here” onboarding path: get a key (with a key-security warning) → plan & quota → first computed call → a first deterministic decline explained as a safety success → support & feedback.
- Every marketing page now carries a shared footer (Docs · Roadmap · Changelog · Feedback · Pricing · Status · Terms · Privacy · Support) so support and privacy guidance are reachable from anywhere.
Workflows published: what-if + review-packet; roadmap & feedback v2
2026-07-06
- POST /api/mcp/tax-compute/what-if — run up to 25 complete scenarios in one call; N independent results (no deltas, no ranking), billed per scenario, Idempotency-Key required.
- POST /api/mcp/tax-compute/review-packet — recompute a set of caller-asserted profiles fresh into a reviewer packet; each item carries its own result and legal notice (no packet-level aggregate), billed per scenario.
- Docs cookbook: 11 copy-paste recipes (federal, CA, NY/NYC, declines, reconcile, workflows, discovery), each with the actual live response.
- The public roadmap's badges are now DERIVED from tracked status axes (engine / certification / API-contract / docs) with a load-time guard — a capability cannot render as shipped-and-certified unless every gate is green. /feedback rebuilt as five structured intake lanes (priority, unsupported case, docs gap, billing issue, support).
- Mobile docs fix: copy buttons no longer overlap code on small screens.
Equity-comp (RSU/NSO) computes; machine-checked capability manifest; binding terms
2026-07-05
- A covered RSU/NSO sale with a comp-adjusted basis now COMPUTES (the routine $0-basis 1099-B double-tax case), gated by preparer affirmations, evidence-backed dates, and a typed ordinary-income source reference; a comp adjustment can never create a loss. ISO/ESPP still decline.
- The capability manifest's decline whitelists are now compile-bound to the engine's own code unions — a decline code added to the engine but left unadvertised fails the build.
- Terms of service published as binding at /terms; the API's legal_notice references it.
- Privacy-safe telemetry beacon (event-name allowlist, no keys/PII/bodies) behind the docs and product pages.
Capital-gain depth: lot/evidence contract, §1256, special rates, rental losses
2026-07-04
- Shared Form 8949 lot/evidence contract (CapGainEntry v0): per-box or per-lot 1099-B aggregates across multiple brokers net through the same capital-gain path; only a clean covered A/D box with the cross-account wash-sale affirmation computes — everything else declines whole-return with no tax-number leakage.
- §1256 contracts (Form 6781): the 2026-07-04 release introduced the affirmed IRS-reported positive aggregate path, which splits statutorily 40% short-term / 60% long-term into Schedule D and the NIIT base. The product now also supports a later bounded no-election aggregate-loss path only when BOTH section1256CleanBrokerReportedAffirmed:true and section1256LossCurrentlyDeductibleAffirmed:true are present; a net of exactly zero, tagged §1256 box/lot inputs, and straddle cases still decline.
- Unrecaptured §1250 (25%) and 28%-rate collectibles gains (2025): stacked special-rate layers above the 0/15/20 bands via the Schedule D Tax Worksheet, with the AMT refigured to match.
- Schedule E rental LOSSES now compute under the §469(i) up-to-$25,000 active-participation allowance (MAGI-phased), with four required affirmations; the disallowed excess is reported as a suspended carryforward, never silently dropped.
Public compute API — GA candidate
2026-07-01
- Deterministic federal 1040 compute: ordinary tax, NIIT (Form 8960), Additional Medicare (Form 8959), preferential LTCG / qualified-dividend bands — standard deduction, whole-dollar per the form's rounding.
- State compute: selected CA 540 and NY / NYC 2025 paths; decline-aware CA reconcile against a filed return (non-mutating).
- Coverage-bounded by design: outside the modeled envelope the engine returns a deterministic 200 decline (code + reason + next_action), never a wrong-but-plausible number.
- Machine-readable discovery: GET /api/mcp/tax-capabilities advertises the per-jurisdiction supported envelope, decline codes, review states, and billing semantics — no taxpayer payload required.
- Uniform response contract on every response: billed (ledger truth), retry_safe, next_action, reason, and provenance on computed results — identical across OpenAPI, docs, and live.
- Idempotency-Key: a retry with the same key + body replays the byte-identical first response and bills exactly once.
- Billing that fails closed: monthly quota is a hard 429 cap (no surprise overage); per-minute rate limits return 429; usage headers (X-Quota-*, X-RateLimit-*) let you back off before a limit.
- Runnable quickstart with a real deterministic-decline example, plus the full OpenAPI 3.1 spec at /api/openapi.json.
- Canonical host tax-mcp.com.