Butr

Butr is an AI-native investing control layer for UK retail investors, starting with Trading 212 and ISA-aware portfolio workflows.

This repo is intentionally designed around a calm, approval-first control layer rather than autonomous trading. The working tree is organized around four high-level buckets: infra, services, platform, and tests. Butr v1 is Stocks & Shares ISA only, with an explicit paper vs live operating mode. For the AI-first MVP, the website is marketing-only and the API is the product surface. See docs/butr-ai-first-mvp.md.

Initial product shape

• Marketing-only website
• API-first control layer for external AI clients
• Deterministic portfolio checks and trade previews
• Approval objects and manual execution tickets
• Portfolio state, rules, previews, approvals, and audit logs as first-class domain concepts

Recommended repo structure

.
├── infra                   # Deploy, env, and infrastructure definitions
├── platform                # Shared domain, web, and product shell
├── services                # Backend product services
└── tests                   # Cross-cutting integration and end-to-end tests

Core architectural principle

The backend is the source of truth. The LLM can interpret intent and explain results, but it never owns portfolio state or execution decisions.

Suggested MVP boundaries

• Trading 212 first
• ISA-aware portfolio workflows
• Read portfolio state, generate trade previews, require approval, then issue execution-ready tickets
• No autonomous strategies
• No public live execution path in v1
• No multi-broker support yet
• No broad financial planning

For the initial system design, see docs/butr-mvp-architecture.md. For the frontend and brand direction, see platform/web/DESIGN.md and docs/butr-brand.md. For the AI client contract, see docs/butr-api.md. For a practical privacy/security launch checklist, see docs/butr-privacy-security-checklist.md.