GLM 5.3 and GPT-5.6 Sol are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
GLM 5.3, from Z.ai, has a 1,048,576-token context window and is priced at $1.40/M tokens input, $4.40/M tokens output on OpenRouter.
GPT-5.6 Sol, from OpenAI, has a 1,050,000-token context window and is priced at $2.50/M tokens input, $15/M tokens output on OpenRouter.