Chat Models
Use chat models for text generation, coding help, reasoning, extraction, and multi-turn assistant workflows. This page helps you choose a chat model. To send requests, use the canonical Chat Completions API guide.
Choose a model
Start from the Models table and compare these fields:
For initial testing, pick a low-cost live model such as qwen3.5-flash. For coding-heavy workloads, start with a coding-oriented model such as kimi-k2.7-code. For long documents or agent workflows, choose a model with enough context for the full prompt and expected tool output.
Common selection patterns
Context planning
Chat requests include everything you send in messages: system instructions, user input, previous turns, retrieved documents, and tool results. Larger context is useful, but it also increases input-token spend.
Before launching a workload:
- Estimate the largest realistic prompt.
- Include conversation history and retrieved context in that estimate.
- Leave room for tool outputs if the model calls functions.
- Set
max_tokenslow enough to control runaway output cost. - Use summarization or retrieval instead of sending unbounded history.
Pricing notes
Chat model pricing is usually split between input and output tokens. Compare both columns before choosing a model.
- For short prompts with long answers, output price matters more.
- For agents, RAG, and multi-turn chat, input price often dominates.
- For coding tasks, context size can matter more than raw token price.
- For production, re-check the Models page before routing new traffic because model availability and pricing can change.
Routing
By default, omit route and let OpenModels use the default available route for the selected model. Pin a provider route only when you need a specific provider for testing, compliance, latency, or deterministic cost comparison.
See Chat Completions for the request shape and route.provider syntax.
Production checklist
Before moving a chat workload to production:
- Confirm the model is live in the Models table.
- Confirm the selected model has enough context.
- Check input and output prices against your expected usage.
- Add credits and configure monthly spend limits for the API key.
- Decide whether the workload needs streaming or function calling.
- Log model ID, token usage, request ID, and gateway errors.
Next steps
- Chat Completions: send chat requests.
- Streaming: stream generated text as server-sent events.
- Function Calling: expose tools to compatible models.
- Pricing Guide: understand token pricing and route costs.