EvoTrader: a self-evolving multi-agent trading system on ADK (open source, research)

[AdamCYH]

I built a research project on ADK and open-sourced it this week: a team of agents that trades a stock or ETF through your own Robinhood account inside hard limits, plus an evolution agent that reads the scored record of past decisions and the source code, then proposes strategy and code changes for a human to approve. The hypothesis — that an agent can re-tune an algorithm and propose strategies as market conditions change — is unproven, and the project publishes no trading results. It runs in practice mode by default.

Repo: https://github.com/AdamCYH/evotrader (Apache 2.0). Architecture notes: docs/architecture.md.

ADK-specific things that might save someone time:

• transfer_to_agent is one-way. A custom BaseAgent reached that way cannot hand control back the way an LlmAgent sub-agent can (its function call returns). We moved the strategy role to a custom agent and silently lost the risk-manager and executor stages for a run of cycles — every cycle "held", and looked healthy. An automated review caught it by noticing no order had been possible. If your pipeline depends on a role returning, reach it as a tool call, not a transfer.
• Per-agent tool-schema filtering. The broker MCP server exposes a lot of tools; giving the executor only the ones it needs cut that agent's prompt roughly in half. A small FilteredMcpToolset wrapper does it.
• A CLI-hosted agent inside ADK. One role (strategy) can run on Claude Code through the Claude Agent SDK instead of the API, wrapped as a BaseAgent, with a pluggable backend registry so other CLIs could slot in. It withholds the API key from the subprocess so usage can only bill the subscription, and reads the SDK's rate-limit events to fall back to the API path when quota runs low.
• Providers via LiteLLM. Gemini is the default; Claude and OpenAI are chosen per agent in settings. Anthropic prompt caching is applied through a small LiteLLM client wrapper.

Happy to answer questions about any of it, and genuinely interested in how others handle the one-way transfer problem.