Summary

Add a new connector package agent/src/trading/connectors/trading212/ mirroring the structure of existing read-only/paper connectors such as dhan and shoonya: __init__.py (package docstring), sdk.py (read-only operations against Trading 212's REST API: account, positions, open orders, history, instrument metadata), profiles.py (TRADING212_PROFILES, capped at read-only since the public API has no runtime paper/live discriminator, following the same hard-refuse rule Dhan/Shoonya use for place_order/cancel_order), and classification.py (TRADING212_TOOL_CLASS mapping each operation to read/write ToolClass). Wire it into the three registries that every connector touches: add the SDK module to _SDK_CONNECTOR_MODULES in agent/src/trading/service.py, import and splice TRADING212_PROFILES into BUILTIN_PROFILES in agent/src/trading/profiles.py, and import and register TRADING212_TOOL_CLASS in the classification map in agent/src/live/registry.py. Add agent/tests/test_trading212_connector.py covering profile registration, read/write classification, and the paper/live hard-refuse on order placement.

Why

The reporter requested a broker connector for Trading 212 (UK/EU retail broker). The maintainer (warren618, COLLABORATOR) responded on 2026-06-27 that Trading 212 is a reasonable candidate and a focused community PR is welcome, with the explicit scoping that the first step stay read-only and avoid live order placement until the broker exposes a clear paper/demo or structural safety boundary. The cleanest first PR is read-only account/positions/orders/history/instrument-metadata support plus connector classification, mirroring the existing connector pattern.

Closes #309

Changes

• Add a new connector package agent/src/trading/connectors/trading212/ mirroring the structure of existing read-only/paper connectors such as dhan and shoonya: __init__.py (package docstring), sdk.py (read-only operations against Trading 212's REST API: account, positions, open orders, history, instrument metadata), profiles.py (TRADING212_PROFILES, capped at read-only since the public API has no runtime paper/live discriminator, following the same hard-refuse rule Dhan/Shoonya use for place_order/cancel_order), and classification.py (TRADING212_TOOL_CLASS mapping each operation to read/write ToolClass). Wire it into the three registries that every connector touches: add the SDK module to _SDK_CONNECTOR_MODULES in agent/src/trading/service.py, import and splice TRADING212_PROFILES into BUILTIN_PROFILES in agent/src/trading/profiles.py, and import and register TRADING212_TOOL_CLASS in the classification map in agent/src/live/registry.py. Add agent/tests/test_trading212_connector.py covering profile registration, read/write classification, and the paper/live hard-refuse on order placement.

Test Plan

• Existing tests pass (pytest --ignore=agent/tests/e2e_backtest --tb=short -q)
• New tests added (if applicable)
• Tested manually (describe below)
• Happy path: the Trading 212 profile is discoverable via BUILTIN_PROFILES and read-only operations classify as read in the live registry. - Edge case: any place_order/cancel_order attempt with a non-paper config is hard-refused at the first line (no structural paper/live guard available), matching the Dhan/Shoonya rule. - Error path: a missing or invalid Trading 212 API key surfaces a clear connector error rather than an unhandled exception; classification falls back to deny for unknown operations.

Checklist

• No changes to protected areas (src/agent/, src/session/, src/providers/) without prior discussion
• No hardcoded values (API keys, file paths, magic numbers)
• Code follows CONTRIBUTING.md guidelines
• Documentation updated (if user-facing change)

AI was used for assistance.