Overview
C1 is family of API endpoints that use different underlying LLM models. The pricing is based on the model family and the amount of tokens used. Pricing is based on model name irrespective of the kind of endpoint you use. For example, using the embed endpoint withc1/anthropic/claude-sonnet-4/v-20250617 is priced the same as using the visualize
endpoint with the same model.
Generally speaking, a model name is more than just the model of the LLM it uses.
It also includes the version of the model, the set of components available for use in the UI,
and any other metadata.
This guide is called “Models” and not “API Versions” because typically you’d pass
the API version to the model parameter in the request to the LLM compatible
endpoints of C1.
- Nightly models are updated daily with the latest changes. NOT recommended for production use.
- Latest models are updated monthly with the latest stable version of the model.
- Stable models are updated in the table below. When shipping in production, use the latest stable model.
Model table
The complete model string always has a version at the end. Latest C1 version
per model is noted in the table below.
Stable and Experimental Models
| C1 Model | LLM | State | Latest C1 Version | Input Price / M tokens | Output Price / M tokens | Context Window | Max Output |
|---|---|---|---|---|---|---|---|
c1/anthropic/claude-sonnet-4/<version> | Sonnet 4 | Stable | v-20250915 | $6.00 | $18.00 | 180K | 64K |
c1/openai/gpt-5/<version> | GPT 5 | Stable | v-20250915 | $2.50 | $12.50 | 380K | 128K |
c1-exp/anthropic/claude-3.5-haiku/<version> | 3.5 Haiku | Experimental | v-20250709 | $1.60 | $5.00 | 180K | 8192 |
c1-exp/openai/gpt-4.1/<version> | GPT 4.1 | Experimental | v-20250617 | $4.00 | $10.00 | 1M | 32K |
Other Models
Deprecated Models
Deprecated Models
| C1 Model | LLM | State | Latest C1 Version | Input Price / M tokens | Output Price / M tokens | Context Window | Max Output |
|---|---|---|---|---|---|---|---|
c1/anthropic/claude-3.5-sonnet/<version> | 3.5 Sonnet | Stable | v-20250709, v-20250617 | $3.50 | $18.00 | 180K | 8192 |
c1/anthropic/claude-3.7-sonnet/<version> | 3.7 Sonnet | Stable | v-20250709, v-20250617 | $6.00 | $18.00 | 180K | 64K |
c1-latest | Sonnet 3.5 | Deprecated | $3.50 | $18.00 | 180K | 8192 | |
c1-202504XX* | Sonnet 3.5 | Deprecated | $3.50 | $18.00 | 180K | 8192 |