5 Errors I Hit Building DeFi Bots (And How to Fix Them)

Description and use

By switching to polling, throttling API usage, adjusting database security, ensuring proper file creation, and adapting terminal workflows, the bots achieved reliable, continuous operation on free-tier services.

Problem

Building production bots on free APIs often fails due to connection timeouts, rate limits, security policies, file system quirks, and mobile terminal limitations.

Outcome

By switching to polling, throttling API usage, adjusting database security, ensuring proper file creation, and adapting terminal workflows, the bots achieved reliable, continuous operation on free-tier services.

Workflow

• Use polling instead of WebSocket listeners for Alchemy events (e.g., poll every 15 min).
• Reduce CoinGecko request frequency or token count to stay below free‑tier limits (e.g., 2 tokens every 2 h).
• Disable RLS on Supabase tables or create permissive INSERT policies when using anon keys.
• Create scripts directly in Termux with nano to avoid file‑creation issues.
• Use mobile‑friendly key sequences (e.g., Ctrl+B then D) or alternative methods to detach tmux sessions.