About
An agent harness built on the premise that the model is the part you should be able to replace.
Agent tooling tends to be written against one vendor and adapted afterwards, which leaves that vendor's assumptions buried where nobody finds them later. OHarness inverts it: history is stored in a neutral format and rendered into a vendor's wire format only at the moment a request goes out. Switching provider mid-session needs no migration because there is nothing to migrate.
The project is MIT licensed and developed in the open. The engine has one runtime dependency, reaches every provider over plain fetch and SSE, and ships its own MCP client — decisions made so the layer you depend on stays small enough to read.