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

# Legacy compat names

> Old DeepSeek model strings (deepseek-chat, deepseek-reasoner) still resolve through ByteSpike until DeepSeek's official 2026/07/24 sunset. New code should target the canonical names — deepseek-v4-flash and deepseek-v4-pro — directly.

ByteSpike accepts a small set of **legacy compat names** that DeepSeek itself has retired. They're kept here so existing customer code keeps working through DeepSeek's official sunset window. New code should not use them.

## Canonical names (recommended)

Write your code against these:

| Canonical name      | What you get                                                                                   |
| ------------------- | ---------------------------------------------------------------------------------------------- |
| `deepseek-v4-flash` | DeepSeek V4 Flash — fast non-thinking mode, default for general chat / completion              |
| `deepseek-v4-pro`   | DeepSeek V4 Pro — adds the thinking / reasoning mode (set `reasoning_effort` to control depth) |

Both are first-class names: they appear in usage exports, audit logs, billing line items, and the [models index](/models) without further translation.

## Legacy compat (until **2026-07-24**)

DeepSeek announced these names will be **removed on 2026-07-24**. ByteSpike's gateway will continue to accept them until then, resolving each request to the canonical name below.

| Legacy name         | Resolves to                       | Note                                   |
| ------------------- | --------------------------------- | -------------------------------------- |
| `deepseek-chat`     | `deepseek-v4-flash`               | The most common pre-V4 DeepSeek string |
| `deepseek-reasoner` | `deepseek-v4-pro` (thinking mode) | The pre-V4 "reasoner" handle           |

After 2026-07-24 these names will return a 400 from ByteSpike (matching DeepSeek's own behavior). Update your code before then.

## Names not to use

Earlier DeepSeek lineages — `deepseek-coder`, `deepseek-v2` family handles — have been retired and are no longer accepted by ByteSpike. Requests using them return a 404 with a hint pointing at the V4 line. (The current DeepSeek line on ByteSpike is `deepseek-v4-flash` / `deepseek-v4-pro`; see the [models index](/models).)

For other model families, ByteSpike accepts the canonical model ID directly. No alias layer applies; there are no synonyms to memorize. Look up the exact string for each model on its [models](/models) page.

## How to migrate

A one-line code change in most clients:

```diff theme={null}
- "model": "deepseek-chat"
+ "model": "deepseek-v4-flash"
```

```diff theme={null}
- "model": "deepseek-reasoner"
+ "model": "deepseek-v4-pro"
```

If you use `deepseek-reasoner` and depend on the thinking output specifically, also confirm your client sets `reasoning_effort` (default is medium on V4 Pro).

## Next

* [Models index](/models) — every canonical model ByteSpike serves, with pricing and protocol coverage
* [Endpoint types](/concepts/endpoints) — the protocols each model can be called through