> Markdown mirror of https://router.one/blog/new-llm-models-october-2026 for AI assistants and crawlers. Router One is a unified, OpenAI-compatible LLM API gateway.
> Published: 2026-10-09 · Author: Router One Team

# New LLMs, Oct 2026: Gemini 3.5 Flash Lite, Nano Banana 2.1

_New on Router One in October 2026: Gemini 3.5 Flash Lite and Nano Banana 2.1, with model IDs, endpoints, plan coverage and a first request for each._

This is the October 2026 sibling of the [September 2026 new-model guide](https://router.one/blog/new-llm-models-september-2026), written the same way: for each catalog or plan change recorded between that post's wrap-up (as of 2026-09-30) and 2026-10-09, what the [live catalog](https://router.one/models) and the plan responses show for the ids involved — which endpoints serve them, whether a plan covers them — and how to send a first request. As of the 2026-10-09 catalog, Router One no longer lists Claude Fable 5.1 (anthropic/claude-fable-5.1) and lists two new ids, Gemini 3.5 Flash Lite (`google/gemini-3.5-flash-lite`) and Gemini Nano Banana 2.1 (`gemini-nano-banana-2.1`). On the plan side, GPT-6.1 Sol and GPT-6 Sol are in the Premium models tier of the Pro, Max and Ultra plans, first seen in the 2026-10-06 plan response.

The 2026-10-09 catalog holds 67 ids — 59 text and 8 image. No plan tier in the 2026-10-09 plan response lists Gemini 3.5 Flash Lite or Gemini Nano Banana 2.1, so their calls bill from the wallet balance at their posted rates; Gemini 3.5 Flash stays in the Standard models tier. Listing dates in this post are catalog observation dates, not vendor launch dates, and the [changelog](https://router.one/blog/changelog) records the same changes.

## October at a glance (as of 2026-10-09)

The table lists each change, the endpoints that serve each id and whether a plan covers it; live rates are on each model page, not here.

| Model | Catalog id | First seen | Endpoints | Plan coverage (2026-10-09) |
| --- | --- | --- | --- | --- |
| [GPT-6.1 Sol](https://router.one/models/gpt-6-1-sol) and [GPT-6 Sol](https://router.one/models/gpt-6-sol) (plan change) | `openai/gpt-6.1-sol`, `openai/gpt-6-sol` | The 2026-10-06 plan response (ids listed 2026-09-30 and 2026-09-23) | Responses, Chat Completions | Premium models tier of Pro, Max and Ultra |
| [Gemini 3.5 Flash Lite](https://router.one/models/gemini-3-5-flash-lite) | `google/gemini-3.5-flash-lite` | The 2026-10-09 catalog | Chat Completions | None — wallet, per token |
| [Gemini Nano Banana 2.1](https://router.one/models/gemini-nano-banana-2-1) | `gemini-nano-banana-2.1` | The 2026-10-09 catalog | Images: generations and edits | None — wallet, per image |
| Claude Fable 5.1 (no longer listed) | anthropic/claude-fable-5.1 | Not in the 2026-10-09 catalog | — | — |

[Claude Fable 5](https://router.one/models/claude-fable-5) (`anthropic/claude-fable-5`) stays listed. Plan model lists change, and the [pricing page](https://router.one/pricing) shows the live ones with each plan's allowance; a model that no plan tier lists bills from the wallet, per token or per image, whether or not you hold a plan.

## GPT-6.1 Sol and GPT-6 Sol in the Premium models tier

As of the 2026-10-06 plan response, [GPT-6.1 Sol](https://router.one/models/gpt-6-1-sol) (`openai/gpt-6.1-sol`) and [GPT-6 Sol](https://router.one/models/gpt-6-sol) (`openai/gpt-6-sol`) are in the Premium models tier of the Pro, Max and Ultra plans, beside GPT-5.6 Sol, GPT-5.5, Claude Opus 5 and the other models that tier lists; the 2026-10-03 plan response listed neither. On a plan, their calls count against the Premium models allowance — 1 request per call, 2 when the total input is strictly above 272,000 tokens — and calls beyond the allowance bill the wallet at the posted rates; the [pricing page](https://router.one/pricing) lists each plan's allowance.

Both are GPT-family ids, served on Chat Completions and natively on Responses, the wire format Codex CLI speaks. On a Pro, Max or Ultra plan, GPT-6.1 Sol counts against the Premium models allowance (as of the 2026-10-06 plan response), and moving Codex from `gpt-5.6-sol` to `gpt-6.1-sol` keeps it on the same allowance. Without a plan, every request Codex sends bills the wallet at GPT-6.1 Sol's posted rates ([model page](https://router.one/models/gpt-6-1-sol)). The [GPT-6.1 Sol API guide](https://router.one/blog/gpt-6-1-sol-api-guide) and the [GPT-6 Sol API guide](https://router.one/blog/gpt-6-sol-api-guide) cover both ids, both endpoints and Codex CLI setup.

## Gemini 3.5 Flash Lite

Router One lists Gemini 3.5 Flash Lite as `google/gemini-3.5-flash-lite` as of the 2026-10-09 catalog. Google writes the name "Gemini 3.5 Flash-Lite"; it made the model generally available on July 21, 2026 and describes it as a low-latency option designed for high-volume automation, per the Gemini API release notes (checked 2026-10-09). The catalog entry lists a 1,048,576-token context window, text and image input and the chat, streaming, tool-calling and vision flags; as a Gemini id it is served on `POST /v1/chat/completions`. It is in no plan tier as of the 2026-10-09 plan response, so its calls bill from the wallet at the posted rates on the [Gemini 3.5 Flash Lite model page](https://router.one/models/gemini-3-5-flash-lite), plan or no plan.

Gemini 3.5 Flash (`google/gemini-3.5-flash`) is a different model: as of the 2026-10-09 plan response it is in the Standard models tier of the Pro, Max and Ultra plans. Gemini 3.1 Flash Lite (`google/gemini-3.1-flash-lite`, with its preview twin `google/gemini-3.1-flash-lite-preview`) is an earlier Flash Lite generation, also in no plan tier in the same response. Per Google's guide to Gemini 3.6 Flash and 3.5 Flash-Lite (checked 2026-10-09), starting with those two models the Gemini API ignores temperature, top_p and top_k and rejects a request whose last turn is a prefilled model turn, and Gemini 3.5 Flash Lite's default thinking level is minimal; Gemini 3.1 Flash Lite and Gemini 3.5 Flash predate these changes. Move tone and format rules into the system message before you switch, then compare on your own prompts: [Gemini 3.5 Flash Lite vs Gemini 3.1 Flash Lite](https://router.one/models/compare/gemini-3-5-flash-lite-vs-gemini-3-1-flash-lite) and [Gemini 3.5 Flash Lite vs Gemini 3.5 Flash](https://router.one/models/compare/gemini-3-5-flash-lite-vs-gemini-3-5-flash) render the spec sheets and live rates side by side.

Access from mainland China for the whole Gemini family is on the [Gemini API in China page](https://router.one/gemini-api-china).

## Gemini Nano Banana 2.1

Google released Gemini Nano Banana 2.1 on October 6, 2026 as an update to Nano Banana 2, per the Gemini API release notes (checked 2026-10-09), and its image generation guide (checked 2026-10-09) calls 2.1 the primary high-efficiency model for image generation and conversational editing and recommends it over Nano Banana 2 for new projects. Router One lists it as `gemini-nano-banana-2.1` as of the 2026-10-09 catalog: text and image input, image output, billed per generated image — its live unit price is on the [Gemini Nano Banana 2.1 model page](https://router.one/models/gemini-nano-banana-2-1). No plan tier in the 2026-10-09 plan response lists it, so each image bills from the wallet balance.

It takes the same two calls as Nano Banana 2 (`gemini-3.1-flash-image-preview`) and Nano Banana Pro (`gemini-3-pro-image-preview`): put `gemini-nano-banana-2.1` in `model` on `POST /v1/images/generations`, or send a reference image to `POST /v1/images/edits`. The size and quality notes in the [Nano Banana 2 API guide](https://router.one/blog/nano-banana-2-api-guide) were written for Nano Banana 2; Google's model page (checked 2026-10-09) lists 1K, 2K and 4K output for 2.1 and its release notes describe improved wide and panoramic aspect-ratio generation, so describe the framing you want in the prompt and check the result. The [image generation API page](https://router.one/image-generation-api) covers the image models on the gateway, each with its own per-image price on its model page.

## Claude Fable 5.1 and the Claude Code aliases

As of the 2026-10-09 catalog, Router One no longer lists Claude Fable 5.1 (anthropic/claude-fable-5.1). [Claude Fable 5](https://router.one/models/claude-fable-5) (`anthropic/claude-fable-5`) stays listed and, as a Claude-family id, is served on `POST /v1/messages` and `POST /v1/chat/completions`, not on `POST /v1/responses`. The September post and the changelog keep their September entries as dated history.

In Claude Code this shows up through the `fable` alias: pin it, and keep the Haiku line too if you use the `haiku` alias. Add these lines to your shell profile (`~/.zshrc` or `~/.bashrc`):

```bash
export ANTHROPIC_DEFAULT_HAIKU_MODEL=claude-haiku-4-5
export ANTHROPIC_DEFAULT_FABLE_MODEL=claude-fable-5
```

If the one-click install wrote your setup, merge the same keys into the `env` block you already have in `~/.claude/settings.json` instead:

```json
{
  "env": {
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "claude-haiku-4-5",
    "ANTHROPIC_DEFAULT_FABLE_MODEL": "claude-fable-5"
  }
}
```

The Haiku line is optional: it runs background tasks on Claude Haiku 4.5 rather than the main model. Per Claude Code's changelog, model configuration and subagents docs (Claude Code 2.1.295, checked 2026-10-09), from 2.1.293 the `haiku` alias resolves to Claude Haiku 5.5 (claude-haiku-5-5), which the 2026-10-09 Router One catalog does not include, so keep the line if you use `/model haiku`, subagents defined with `model: haiku` or the built-in claude-code-guide subagent (which the subagents docs list as running on Haiku). The Fable line points the `fable` alias at Claude Fable 5: per Claude Code's model configuration docs (Claude Code 2.1.295, checked 2026-10-09), the alias otherwise resolves to Claude Fable 5.1 (claude-fable-5-1), which Router One no longer lists as of the 2026-10-09 catalog. Claude Fable 5 is in no plan tier as of the 2026-10-09 plan response, so it bills to the wallet.

Plan holders also pin the `sonnet` and `opus` aliases and the main model; the [Claude Code setup guide](https://router.one/blog/claude-code-setup-guide) has the full block and explains each line.

## Which endpoint serves which id

Endpoint families are not interchangeable. `POST /v1/chat/completions` serves every chat model in the catalog; `POST /v1/messages` serves the Claude-family and DeepSeek ids; `POST /v1/responses` is served natively for the GPT-family and DeepSeek ids and for the Grok chat ids. A Claude-family id sent to `/v1/responses`, or a chat id outside the Claude and DeepSeek families sent to `/v1/messages`, is rejected with HTTP 400 `invalid_request_error` before any model is called, and the message names the path to use. Image models take the Images API instead: `POST /v1/images/generations` for a prompt, `POST /v1/images/edits` for a prompt plus a reference image. For the ids in this post that means: GPT-6.1 Sol and GPT-6 Sol on Responses or Chat Completions; Gemini 3.5 Flash Lite on Chat Completions; Gemini Nano Banana 2.1 on the two image endpoints; and Claude Fable 5 on Messages or Chat Completions. The [OpenAI-compatible API page](https://router.one/openai-compatible-api) covers the request shape, and each model page lists exactly the endpoints it serves.

## How to try one in five minutes

1. **Create a key.** Dashboard → API Keys → Create Key. Keys look like `sk-...`. If this is an experiment, give the key a `maxSpend` cap so a runaway loop stops at a number you chose ([per-key cost tracking](https://router.one/llm-cost-tracking)).
2. **Set the base URL.** `https://api.router.one/v1` for OpenAI-compatible clients and SDKs; the chat and image endpoints both sit under it and take the same key.
3. **Send one request per model.**

Gemini 3.5 Flash Lite on Chat Completions:

```bash
curl https://api.router.one/v1/chat/completions \
  -H "Authorization: Bearer sk-your-api-key" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "google/gemini-3.5-flash-lite",
    "messages": [
      {"role": "system", "content": "Classify the ticket as billing, bug or question. Reply with one word."},
      {"role": "user", "content": "The invoice shows the wrong company name."}
    ]
  }'
```

Gemini Nano Banana 2.1 on the Images API:

```bash
curl https://api.router.one/v1/images/generations \
  -H "Authorization: Bearer sk-your-api-key" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gemini-nano-banana-2.1",
    "prompt": "Isometric illustration of a night market, warm lantern light, no text"
  }'
```

Every image the call returns is billed at the per-image unit price on the model page. The [Nano Banana 2 API guide](https://router.one/blog/nano-banana-2-api-guide) shows how to handle the response and how to send a reference image to `/v1/images/edits`, and the [Images API docs](https://router.one/docs/images/createImageGeneration) list the fields.

4. **Read the trace.** Dashboard → Logs lists both calls with the model, cost, latency and status, so you see what each call cost before you wire either model into your app ([per-request observability](https://router.one/llm-observability)).

Top up with a card or Alipay through one hosted checkout, or with USDT/USDC on six chains (Tron, BSC, Ethereum, Polygon, Base, Arbitrum). No US credit card required. Requests reach the catalog from mainland China without a VPN.

## FAQ

**What is the model id for Gemini 3.5 Flash Lite, and does a plan cover it?**
The id is google/gemini-3.5-flash-lite, called on /v1/chat/completions with a Router One key. It is in no plan tier as of the 2026-10-09 plan response, so its calls bill from the wallet balance at the posted rates on its model page, plan or no plan. Gemini 3.5 Flash (google/gemini-3.5-flash) is a different model, and the Standard models tier of the Pro, Max and Ultra plans lists it in the same response.

**Should I use Gemini 3.5 Flash Lite or Gemini 3.1 Flash Lite?**
Both are Chat Completions ids with a 1,048,576-token context window and text and image input in the 2026-10-09 catalog, and both are in no plan tier as of the 2026-10-09 plan response. Per Google's guide to Gemini 3.6 Flash and 3.5 Flash-Lite (checked 2026-10-09), starting with those two models the Gemini API ignores temperature, top_p and top_k and rejects a request whose last turn is a prefilled model turn, and Gemini 3.5 Flash Lite's default thinking level is minimal; Gemini 3.1 Flash Lite predates these changes. Move tone and format rules into the system message, run your own prompts through both and compare each request's cost in Dashboard → Logs; [Gemini 3.5 Flash Lite vs Gemini 3.1 Flash Lite](https://router.one/models/compare/gemini-3-5-flash-lite-vs-gemini-3-1-flash-lite) renders both spec sheets and live rates.

**Is Gemini 3.5 Flash Lite the same model as Gemini 3.5 Flash?**
No. google/gemini-3.5-flash-lite and google/gemini-3.5-flash are two catalog ids with their own rates. As of the 2026-10-09 plan response, Gemini 3.5 Flash is in the Standard models tier of the Pro, Max and Ultra plans and Gemini 3.5 Flash Lite is in no plan tier. On a plan, the choice therefore also decides whether a call draws plan quota or bills the wallet. Per Google's guide to Gemini 3.6 Flash and 3.5 Flash-Lite (checked 2026-10-09), Gemini 3.5 Flash predates the sampling-parameter and prefill changes that start with those two models; [Gemini 3.5 Flash Lite vs Gemini 3.5 Flash](https://router.one/models/compare/gemini-3-5-flash-lite-vs-gemini-3-5-flash) puts the two side by side.

**Should I use Nano Banana 2.1, Nano Banana 2 or Nano Banana Pro?**
All three are in the 2026-10-09 catalog — gemini-nano-banana-2.1, gemini-3.1-flash-image-preview and gemini-3-pro-image-preview — and take the same Images API requests, each billed per image at the unit price on its own model page. Google's image generation guide (checked 2026-10-09) describes Nano Banana 2.1 as an update to Nano Banana 2 and the primary high-efficiency model for image generation and conversational editing, recommends it over Nano Banana 2 for new projects, and positions Nano Banana Pro for the most complex visual tasks. Run your own prompts through each: swap the model string, compare the images, and compare each request's cost in Dashboard → Logs.

**Do GPT-6.1 Sol and GPT-6 Sol count against a plan's allowance?**
Yes, on a Pro, Max or Ultra plan. Both are in the Premium models tier, first seen in the 2026-10-06 plan response, so each call draws the Premium models allowance — 1 request per call, 2 when the total input is strictly above 272,000 tokens — and calls beyond the allowance bill the wallet at the posted rates. Without a plan, their calls bill per token from the wallet. The pricing page lists each plan's allowance.

**Can I still use Claude Fable 5.1?**
As of the 2026-10-09 catalog, Router One no longer lists Claude Fable 5.1, so call Claude Fable 5 (anthropic/claude-fable-5) by id instead. In Claude Code, pin the fable alias with ANTHROPIC_DEFAULT_FABLE_MODEL=claude-fable-5 (the fable alias otherwise requests claude-fable-5-1, which Router One no longer lists as of the 2026-10-09 catalog). Claude Fable 5 is in no plan tier as of the 2026-10-09 plan response, so it bills to the wallet.

## Next steps

- Check the [Gemini 3.5 Flash Lite](https://router.one/models/gemini-3-5-flash-lite) and [Gemini Nano Banana 2.1](https://router.one/models/gemini-nano-banana-2-1) model pages for live rates and capability flags.
- Compare before you switch: [Gemini 3.5 Flash Lite vs Gemini 3.1 Flash Lite](https://router.one/models/compare/gemini-3-5-flash-lite-vs-gemini-3-1-flash-lite) and [Gemini 3.5 Flash Lite vs Gemini 3.5 Flash](https://router.one/models/compare/gemini-3-5-flash-lite-vs-gemini-3-5-flash).
- Generate and edit images with the [Nano Banana 2 API guide](https://router.one/blog/nano-banana-2-api-guide) and the [image generation API page](https://router.one/image-generation-api).
- See which models each plan tier lists, and each plan's allowance, on the [pricing page](https://router.one/pricing).
- Read the [September 2026 guide](https://router.one/blog/new-llm-models-september-2026) for the previous batch — GPT-6 Sol, Claude Opus 5.5, GPT-6 Astra and GPT-6.1 Sol among them.
- Set up Claude Code with the [Claude Code setup guide](https://router.one/blog/claude-code-setup-guide), or point Codex CLI at a GPT id with the [Codex and Responses API guide](https://router.one/codex-responses-api).

## See also

- Canonical page: https://router.one/blog/new-llm-models-october-2026
- LLM API Gateway and Routing: https://router.one/llm-api-gateway
- All blog posts: https://router.one/blog
- Models and per-model token rates: https://router.one/models (markdown: https://router.one/models.md)
- Pricing: https://router.one/pricing
- API docs (markdown): https://router.one/docs.md
- Company facts: https://router.one/facts/company.md