# Inkling 256K

Inkling 256K is a text generation model from Thinking Machines, available through the Impossibl API. Its published context window is 262,144 tokens. The advertised input rate is $3.74 per million input tokens. The advertised output rate is $9.36 per million output tokens.

- Model identifier: ` thinkingmachines/inkling-256k `
- Creator: Thinking Machines
- Model type: Text generation
- Canonical model page: [Inkling 256K](<https://impossibl.com/thinkingmachines/inkling-256k>)
- API availability: Listed as serving through Impossibl.
- Creator release date: 2026-07-15

## Capabilities and limits

- Context window: 262,144 tokens
- Maximum output tokens: Not published in the public catalog; this is separate from the context window.
- Inputs: text, image
- Outputs: text
- Tool calling: Not published

## API access

Use ` thinkingmachines/inkling-256k ` as the model identifier through the Impossibl API.

Published API endpoints:

- ` /v1/chat/completions `

[API quickstart](<https://impossibl.com/docs/agent-quickstart>) · [Models and billing documentation](<https://impossibl.com/docs/models>)

## Published API prices

All rates are in USD. An unpublished rate is unknown, not zero. Workspace-specific pricing, taxes, balance-purchase fees, billing adjustments, and tool charges can affect the amount paid.

| Usage | Published base rate | Billing unit |
| --- | --- | --- |
| Input | $3.74 | per million input tokens |
| Output | $9.36 | per million output tokens |
| Cache read | $0.748 | per million cached input tokens |
| Cache write (default retention) | Not published | per million tokens |
| Cache write (one-hour retention) | Not published | per million tokens |
| Audio input | Not published | per million audio input tokens |

## Availability and retirement

The model is listed as serving. No retirement is announced in the current public catalog.

## Frequently asked questions

### What is Inkling 256K?

Inkling 256K is a text-generation model from Thinking Machines, available through the Impossibl API.

### How much does Inkling 256K cost?

Inkling 256K costs $3.74 per million input tokens and $9.36 per million output tokens through the Impossibl API. Cache reads cost $0.748 per million tokens. All rates are in USD.

### What is the context length of Inkling 256K?

Inkling 256K has a 262,144-token context window through the Impossibl API.

### What inputs and outputs does Inkling 256K support?

Inkling 256K accepts text and image as input. Inkling 256K returns text.

### How do I use Inkling 256K through an API?

Inkling 256K is available through the Impossibl API. Use thinkingmachines/inkling-256k as the model identifier with /v1/chat/completions. The quickstart explains how to create an API key and send your first request.

### When was Inkling 256K released?

Thinking Machines released Inkling 256K on July 15, 2026.

Sources: [Creator release announcement](<https://thinkingmachines.ai/news/introducing-inkling/>)

## Sources and related links

Prices, limits, capabilities, endpoints, and availability come from the public Impossibl catalog. Creator documentation supplies descriptions and release dates where available; it does not override the published API offering.

- [Public Impossibl model catalog](<https://api.impossibl.com/v1/models>)
- [Full model directory as JSON](<https://impossibl.com/models.json>)
- [Inkling 256K: model details and pricing](<https://impossibl.com/thinkingmachines/inkling-256k>)
- [Model directory](<https://impossibl.com/models>)