LibreChat is the leading open-source AI chat platform, a self-hosted ChatGPT alternative with multi-model chat, agents, file handling, and search. Custom endpoints are a headline feature: one block in librechat.yaml adds any OpenAI-compatible provider. Point it at Opper and your whole workspace chats across 700+ models on one key, with a choice of EU or US inference behind it.
RunLibreChatonin
Connect LibreChat to GLM-5.3-Flash
Set up with agents
Paste this into your coding agent (Claude Code, Cursor, Codex, and more) and it will set up and build with Opper for you.
GLM-5.3-Flash runs on the routes below. Route only to EU providers when your data has to stay in Europe. Some routes also sell flex and priority processing: the same model at another price, picked per request with service_tier. How service tiers work.
GLM-5.3-Flash by Z.ai is a natively multimodal 320B MoE with 18B active parameters, hybrid sparse and linear attention, a 1M-token context, and MIT open weights for coding and agent work.