> ## Documentation Index
> Fetch the complete documentation index at: https://docs.v3code.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Models overview

> BYOK providers and hosted routing.

V3Code runs one agent across several models. You pick the model, or let the router pick — the mode and everything else stays the same. The whole system is built around one idea: **get the best models while keeping caching intact so it stays cheap.**

## The V3 models (DeepSeek, optimized)

* **v3fast** — an optimized version of **DeepSeek V4 Flash**: quick and cheap for everyday edits.
* **v3pro** — an optimized version of **DeepSeek V4 Pro**: the stronger workhorse the editor was built around.

"Optimized" means the system around them is tuned to cache well and do the most with the fewest tokens — that's where a lot of the cost savings come from.

## The Anthropic hybrids

These ship as **hybrids that consult Anthropic** — a cheaper model does the work and calls in a stronger one only when the task gets hard, so you get top-tier results without paying top-tier prices on every step.

| Hybrid                 | How it works                                                        |
| ---------------------- | ------------------------------------------------------------------- |
| **Opus Easy**          | **Haiku** does the work and **calls Opus** for the difficult parts. |
| **Opus Hard**          | **Sonnet 5** does the work and **calls Opus** when needed.          |
| **Hybrid (switching)** | Switches between **Sonnet, Opus, and Fable 5** as the task demands. |

To you it behaves like a single model — the switching and escalation happen underneath.

## Auto: let it route

**Auto** picks and escalates for you. A cheaper model handles the easy steps and a stronger one takes over when needed. Auto is tuned to **preserve prompt caching** rather than break it — reshuffling the context every turn would throw away the cache and run up the bill, so V3Code steers the agents to keep the cache working.

## Free, BYOK, and paid

* We work hard on the caching to make Anthropic as good as possible for **BYOK** users (your own Anthropic key) and as cheap as possible for **paid** users.
* **Paid users get customized versions of the Auto and hybrid routers** — tuned to save money and use the fewest tokens. These are unlocked for paid BYOK users and paid plan users.

See [BYOK](/models/byok) for keys and [Plans](/models/plans-and-trials) for what's unlocked where.