ADR 0050 — Fidelity API surface: target WIX (Wealthscape Integration Xchange), fallback FDX read-only

Status: Proposed — contingent on BLR eligibility finding
Date: 2026-05-05
Deciders: software-architect, operator (Kristerpher), BLR
Context doc: fidelity-broker-integration.md §3
Parent epic: (to be filed)

Context

Fidelity exposes several API surfaces to third parties. Raxx's BYOB strategy (2026-04-29) requires an API surface that supports full order routing (submit, bracket, cancel, fill retrieval). Multiple surfaces exist but differ significantly in capability, auth UX, and partner-onboarding friction.

This ADR records which surface to target and why.

Decision

Primary target: Wealthscape Integration Xchange (WIX)

WIX is Fidelity's institutional-grade API program supporting full order lifecycle via REST (and FIX for high-frequency use, out of scope for Raxx v1). It is the only Fidelity surface that provides authenticated order submission for a third-party application routing orders on behalf of retail customers.

Fallback (if WIX access is denied or delayed): FDX (Open Finance Data Exchange) for account/portfolio read-only. FDX enables a "view Fidelity portfolio in Raxx" feature with lighter-weight partnership requirements, while WIX partnership is pursued in parallel.

This decision is contingent on BLR confirming Raxx's eligibility for WIX. If BLR returns that WIX requires RIA registration or AUM thresholds Raxx cannot satisfy in the current period, the primary surface drops to FDX read-only and live order routing is deferred.

Consequences

Positive

• WIX provides the full capability required for live-broker handoff: order submission, bracket/OCO (subject to BLR confirmation), trailing stops, fills, position management.
• WIX uses standard OAuth 2.0 with PKCE — consistent with the existing Alpaca OAuth pattern (ADR 0014); no novel auth mechanism to design.
• The decision is reversible: if WIX is unavailable, FDX provides a useful subset without sunk cost, because the BrokerAdapter abstraction (ADR 0052) remains the same.

Negative

• WIX requires a formal Fidelity Institutional partner agreement. Timeline is unknown and could be months. Engineering cannot begin integration tests until a sandbox is available post-agreement.
• The ATP (Active Trader Pro) unofficial API path is permanently rejected — it is not a viable option (ToS violation, no partner agreement possible).
• FDX fallback provides no order routing. A "connect Fidelity to Raxx" feature in fallback mode is limited to portfolio view.

Neutral

• Raxx is not currently a registered RIA or BD. WIX eligibility may require consulting securities counsel — flagged as BLR open question #2.

Alternatives considered

Active Trader Pro (ATP) unofficial API

Rejected. No documented partner path. The ATP local API is reverse-engineered. Using it would violate Fidelity's terms of service and is not defensible in any partnership conversation.

FDX as primary (not fallback)

Rejected as primary. FDX 6.0 does not support securities order submission. A "view Fidelity portfolio" feature has limited standalone value for Pro+ users who joined Raxx for automated order routing. FDX is appropriate only as a fallback while WIX is pursued.

Aggregator (SnapTrade / Plaid Investments) as a Fidelity proxy

Considered, deferred. The BYOB hybrid strategy already includes an aggregator slot. Using an aggregator to route to Fidelity (instead of first-party WIX) is a valid path if WIX partnership is unavailable. However, aggregators add a dependency layer and revenue share. First-party WIX is preferable where accessible. This alternative is revisited if BLR confirms WIX is inaccessible in the current period.

Revisit when

• BLR delivers WIX eligibility finding (expected: BLR parallel track, no committed date).
• Raxx reaches AUM or user-count thresholds that would satisfy WIX partner requirements.
• FDX adds securities order submission in a future spec version.