Seed 1.6 Flash and GLM 4.6V are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
Seed 1.6 Flash, from bytedance-seed, has a 262,144-token context window and is priced at $0.075/M tokens input, $0.30/M tokens output on OpenRouter.
GLM 4.6V, from Z.ai, has a 131,072-token context window and is priced at $0.30/M tokens input, $0.90/M tokens output on OpenRouter.