Ember-1 API

Q: What is the Ember-1 model ID?

Use fireworks/ember-1 as the model parameter. Requests go to the OpenAI-compatible endpoint with your AI/ML API key.

Fireworks Research's reasoning model built on Kimi K3, tuned to spend fewer thinking tokens per answer. 1M-token context, image input.

Modalities: Image, TextText
In / Out price: $3.17/$15.87per 1M
Context window: 1.05M tokens
Released: Sep 23, 2026

Ember-1 overview

Ember-1 by Fireworks

Ember-1 API: Fireworks Research's reasoning model built on Kimi K3, with a 1,048,576-token context window and shorter reasoning traces.

Ember-1 specs

Model ID: fireworks/ember-1
Developer: Fireworks
Context window: 1,048,576 tokens
Max output: 943,718 tokens
Input: Image, Text
Output: Text
API: OpenAI-compatible, base URL https://api.aimlapi.com/v1

What Is Ember-1?

Ember-1 is a specialised reasoning model from Fireworks Research, built on top of Kimi K3. Its design goal is narrow and concrete: make every token go further by producing shorter reasoning traces. A reasoning model bills its thinking tokens at the output rate, so a model that reaches the same answer with less deliberation costs less per task even at the same headline price.

It inherits Kimi K3's long context, 1,048,576 tokens in, up to 943,718 out, and accepts images alongside text.

Technical Reference

Base model: Kimi K3 (Moonshot AI)
Release date: 23 September 2026
Endpoint: POST /v1/chat/completions
Context window: 1,048,576 tokens
Modalities: Image, Text → Text
Capabilities: reasoning, tool calling, structured output, streaming, vision

What Ember-1 Brings to the Table

Shorter reasoning traces
The model is tuned to think less per answer rather than to think better. On a reasoning workload the thinking tokens are usually the bulk of the bill, so trace length is the lever that moves cost.

Kimi K3's context, unchanged
A 1,048,576-token window holds whole repositories or document sets in one request, with room for very long replies.

Agentic plumbing
Tool calling, structured output and streaming are all supported, alongside image input.

Where Ember-1 Makes the Most Sense

High-volume reasoning
Pipelines that run many reasoning calls, where the thinking-token bill decides whether the workload is viable.

Long-context analysis
Repository-scale code review and long-document research in a single request.

Agent loops
Multi-step work that plans, calls tools and checks itself, where every step pays for its own reasoning.

Use cases

High-volume reasoning where thinking tokens dominate the bill
Repository-scale code review and refactoring
Long-document research and extraction
Agent loops that reason at every step

Capabilities

Reasoning
Function calling
Streaming
Structured outputs
Vision

Ember-1 API pricing

Ember-1 pricing in US dollars
Usage	Price	Unit
Input	$3.17	1M tokens
Output	$15.87	1M tokens
Cached input	$0.3174	1M tokens

Prices from the AI/ML API price list, checked on Nov 4, 2026.

Ember-1 vs other models: token prices

AI/ML API input and output rates for 5 models, per million tokens.

AI/ML API model prices in USD per million tokens
Model	Input	Output
Ember-1	$3.17	$15.87
Claude Sonnet 4	$3.17	$15.87
Claude-Sonnet-4	$3.17	$15.87
GPT 4o 2024‑05‑13	$5.29	$15.87
GPT-5.4 Image 2	$8.46	$15.87

How to use the Ember-1 API

View docs

Build with your agent

Give your agent the model details, code and documentation.

1Get your API key

Create API key

export AIMLAPI_KEY="8f2b4c7d9a1e6b3f…"

2Make your first request

curl 'https://api.aimlapi.com/v1/chat/completions' \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
  "model": "fireworks/ember-1",
  "messages": [
    {
      "role": "user",
      "content": "Write a haiku about the ocean."
    }
  ]
}'

import os
import requests

headers = {
    "Authorization": f"Bearer {os.environ['AIMLAPI_KEY']}",
    "Content-Type": "application/json",
}
payload = {
    "model": "fireworks/ember-1",
    "messages": [
        {
            "role": "user",
            "content": "Write a haiku about the ocean."
        }
    ]
}

response = requests.post("https://api.aimlapi.com/v1/chat/completions", headers=headers, json=payload, timeout=120)
response.raise_for_status()
print(response.json())

const response = await fetch("https://api.aimlapi.com/v1/chat/completions", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "model": "fireworks/ember-1",
    "messages": [
      {
        "role": "user",
        "content": "Write a haiku about the ocean."
      }
    ]
  }),
});

if (!response.ok) throw new Error(`HTTP ${response.status}`);
console.log(await response.json());

Ember-1 FAQ

What is Ember-1?

Ember-1 is a reasoning model from Fireworks Research, built on Moonshot AI's Kimi K3. It is tuned to produce shorter reasoning traces, to reach an answer while spending fewer thinking tokens on the way there.

How much does the Ember-1 API cost?

Ember-1 costs $3.17 input and $15.87 output per 1M tokens on AI/ML API, billed as you go with no subscription.

What is the context window of Ember-1?

1,048,576 tokens in and up to 943,718 tokens out, inherited from Kimi K3, enough for repository-scale code and very long replies in a single request.

How do I call Ember-1 through the API?

Send a POST request to https://api.aimlapi.com/v1/chat/completions with fireworks/ember-1 as the model id and your AI/ML API key in the Authorization header. The endpoint is OpenAI-compatible, so an existing chat client only needs the base URL swapped.

What is the Ember-1 model ID?

Use fireworks/ember-1 as the model parameter. Requests go to the OpenAI-compatible endpoint with your AI/ML API key.

Start building with Ember-1

Get API key

Ember-1 API

fireworks/ember-1

Build with your agent

Give your agent the model details, code and documentation.

1Get your API key

Create API key

export AIMLAPI_KEY="8f2b4c7d9a1e6b3f…"

2Make your first request

curl 'https://api.aimlapi.com/v1/chat/completions' \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
  "model": "fireworks/ember-1",
  "messages": [
    {
      "role": "user",
      "content": "Write a haiku about the ocean."
    }
  ]
}'

import os
import requests

headers = {
    "Authorization": f"Bearer {os.environ['AIMLAPI_KEY']}",
    "Content-Type": "application/json",
}
payload = {
    "model": "fireworks/ember-1",
    "messages": [
        {
            "role": "user",
            "content": "Write a haiku about the ocean."
        }
    ]
}

response = requests.post("https://api.aimlapi.com/v1/chat/completions", headers=headers, json=payload, timeout=120)
response.raise_for_status()
print(response.json())

const response = await fetch("https://api.aimlapi.com/v1/chat/completions", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "model": "fireworks/ember-1",
    "messages": [
      {
        "role": "user",
        "content": "Write a haiku about the ocean."
      }
    ]
  }),
});

if (!response.ok) throw new Error(`HTTP ${response.status}`);
console.log(await response.json());

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Ember-1 API

Ember-1 overview

Ember-1 by Fireworks

Ember-1 specs

What Is Ember-1?

Technical Reference

What Ember-1 Brings to the Table

Where Ember-1 Makes the Most Sense

Use cases

Capabilities

Ember-1 API pricing

Ember-1 vs other models: token prices

How to use the Ember-1 API

Build with your agent

1Get your API key

2Make your first request

Ember-1 FAQ

Start building with Ember-1

Ember-1 API

Build with your agent

1Get your API key

2Make your first request

Ember-1 API

Ember-1 overview

Ember-1 by Fireworks

Ember-1 specs

What Is Ember-1?

Technical Reference

What Ember-1 Brings to the Table

Where Ember-1 Makes the Most Sense

Use cases

Capabilities

Ember-1 API pricing

Ember-1 vs other models: token prices

How to use the Ember-1 API

Build with your agent

1Get your API key

2Make your first request

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