# Ember-1

Ember-1 is Fireworks Research's post-trained version of Kimi K3, tuned to reason in shorter traces at comparable quality, which Fireworks reports as roughly 40% fewer output tokens. It keeps Kimi K3's long context, image input and tool use, and can reason before answering or answer directly. Its published context window is 1,048,576 tokens. The advertised input rate is $3.00 per million input tokens. The advertised output rate is $15.00 per million output tokens.

- Model identifier: ` fireworks/ember-1 `
- Creator: Fireworks
- Providers: Fireworks
- Model type: Text generation
- Canonical model page: [Ember-1](<https://impossibl.com/fireworks/ember-1>)
- API availability: Listed as serving through Impossibl.
- Creator release date: 2026-09-23

## Providers

Fireworks hosts Ember-1. Impossibl routes your request intelligently and handles failover automatically when a provider is down.

| Provider | Endpoint location | Routes | Verified context window | Tool calling |
| --- | --- | --- | --- | --- |
| Fireworks | Not specified | 1 | Not verified | Not verified |

The model price applies whichever provider serves the request. Endpoint locations do not guarantee inference residency.

## Specs and Capabilities

- Context window: 1,048,576 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 ` fireworks/ember-1 ` 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 An unpublished rate is unknown, not zero.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 | $3.00 | per million input tokens |
| Output | $15.00 | per million output tokens |
| Cache read | $0.30 | 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 Ember-1?

Ember-1 is Fireworks Research's post-trained version of Kimi K3, tuned to reason in shorter traces at comparable quality, which Fireworks reports as roughly 40% fewer output tokens. It keeps Kimi K3's long context, image input and tool use, and can reason before answering or answer directly.

Sources: [Introducing Ember-1](<https://fireworks.ai/blog/ember-1>); [Fireworks model page](<https://fireworks.ai/models/fireworks/ember-1>)

### How much does Ember-1 cost?

Ember-1 costs $3.00 per million input tokens and $15.00 per million output tokens through the Impossibl API. Cache reads cost $0.30 per million tokens. All rates are in USD.

### What is the context length of Ember-1?

Ember-1 has a 1,048,576-token context window through the Impossibl API.

### What inputs and outputs does Ember-1 support?

Ember-1 accepts text and image as input. Ember-1 returns text.

### How do I use Ember-1 through an API?

Ember-1 is available through the Impossibl API. Use fireworks/ember-1 as the model identifier with /v1/chat/completions. The quickstart explains how to create an API key and send your first request.

### When was Ember-1 released?

Fireworks released Ember-1 on September 23, 2026.

Sources: [Creator release announcement](<https://fireworks.ai/blog/ember-1>)

## 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>)
- [Ember-1: model details and pricing](<https://impossibl.com/fireworks/ember-1>)
- [Model directory](<https://impossibl.com/models>)
- [Introducing Ember-1](<https://fireworks.ai/blog/ember-1>)
- [Fireworks model page](<https://fireworks.ai/models/fireworks/ember-1>)