51 - Broker And System Configuration

Configuration Sources

Tradeboard does not use a config_service.py or broker configuration database. Runtime settings come from:

Source	Examples
.env	Broker keys, redirect/host/WebSocket URLs, database paths, rate limits, security flags
broker/*/plugin.json	Broker name, type, exchanges, leverage capability
Main settings tables	Analyzer mode, SMTP, notification/application preferences

Environment validation runs before application imports. Import-time settings require a restart after change.

Broker Credential API

blueprints/broker_credentials.py provides session-authenticated /api/broker/credentials GET/POST and /api/broker/capabilities GET.

GET masks secrets with a fixed-length suffix and returns raw length separately for UI state. POST writes only supplied values to .env, validates redirect/host/WebSocket formats and selected broker-specific composite keys, and returns restart_required: true.

The UI is part of frontend/src/pages/Profile.tsx. Broker selection/login uses BrokerSelect.tsx and BrokerTOTP.tsx.

Public Broker Config

GET /auth/broker-config always exposes the broker name needed to render login. API key and redirect URL are returned only for an authenticated app session. The route derives the broker key from the configured callback URL.

Capability Loading

At startup utils/plugin_loader.py calls load_broker_capabilities(), which reads every broker/*/plugin.json that declares supported_exchanges into the module-level _broker_capabilities dict. All 36 plugins qualify today: 34 securities brokers, Delta Exchange for crypto derivatives, and a Dhan sandbox plugin for paper trading. /api/broker/capabilities reads the broker from the Flask session and serves the cached record through get_broker_capabilities(). No session broker returns HTTP 400. A missing capability record falls back to a minimal IN_stock object with an empty supported_exchanges list and leverage_config: false.

Security Boundaries

• .env is installation-secret state and must not be committed.
• Browser reads receive masked credentials; writes never echo submitted secrets.
• Changes are CSRF-protected and session-authenticated.
• Updating .env is not hot reload; restart is explicit.
• Login-time broker tokens are encrypted in database/auth_db.py, separate from static broker application credentials.

Key Files

File	Purpose
.sample.env	Environment contract and defaults
utils/env_check.py	Startup validation
utils/plugin_loader.py	Plugin/capability discovery
blueprints/broker_credentials.py	Credential and capability API
blueprints/auth.py	Broker config/login routes
frontend/src/pages/Profile.tsx	Configuration UI
broker/*/plugin.json	Capability metadata