Free, fully offline cross-platform desktop API client — HTTP, SOAP, gRPC, WebSocket, GraphQL, SSE, MCP. Your data never leaves your machine. MIT source.
Latest release v1.5.3 — Testnizer v1.5.3 · 21 Aug 2026
1 file for Codex and OpenCode: testnizer AGENTS.md — 520 tokens loaded in every session.
AGENTS.md A 520 tok These files are apinizer/testnizer's own configuration — they tell Codex and OpenCode how to work on this repository, so they are not mods to install elsewhere. Copy one as a starting point and replace the parts that are about this project.