Inside Sika Agent: What Two Models Compute When Your Request Comes in Twi–English

An interpretability study of two open reasoning models on matched English, Twi and Twi–English mobile money tasks. Earlier this month (October 2026) I released sika-agent, an RL environment where an agent runs a Ghanaian mobile money wallet through tools: sending money, buying airtime, paying bills, repaying a device loan, and dealing with scams and planted instructions. Every task can arrive in English, Twi or Twi–English, which in the Ghanaian context is what a lot more people speak. MoMo scam calls and texts are incredibly annoying and in this era i figured why not use RL to catch the bad actorsI built sika-agent, an open RL environment for training AI agents that refuse these scams in English, Twi and especially Twi–English, because that mix is how I hear most people actually talk.On results: Qwen3.5-9B completes 86% in English and 51% in Twi. The frontier models I ran stay at 90% or above in every language (about 240 tasks per model). That gap is what training small,…