Spot Serverless

Spot is a separate serverless offering for workloads that can tolerate temporary capacity limits. It uses the same OpenAI-compatible API as Standard and costs 30% less. Use Spot for background, batch, and other cost-sensitive traffic that can wait through a retry or move to Standard.

Spot is best-effort. It has no availability or throughput guarantee, and available throughput can fall to zero.

Select Spot with its model identifier. service_tier does not select Spot.

Models

Model	Spot model identifier	Standard model identifier
GLM-5.3	`accounts/fireworks/models/glm-5p3-spot`	`accounts/fireworks/models/glm-5p3`
Kimi K3	`accounts/fireworks/models/kimi-k3-spot`	`accounts/fireworks/models/kimi-k3`
DeepSeek V4.1 Flash	`accounts/fireworks/models/deepseek-v4p1-flash-spot`	`accounts/fireworks/models/deepseek-v4p1-flash`

Make a request

Python (Fireworks SDK)
Python (OpenAI SDK)
JavaScript
curl

from fireworks import Fireworks

client = Fireworks()

response = client.chat.completions.create(
  model="accounts/fireworks/models/kimi-k3-spot",
  messages=[{"role": "user", "content": "Explain mixture-of-experts models."}]
)

print(response.choices[0].message.content)

import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ.get("FIREWORKS_API_KEY"),
    base_url="https://api.fireworks.ai/inference/v1"
)

response = client.chat.completions.create(
    model="accounts/fireworks/models/kimi-k3-spot",
    messages=[{
        "role": "user",
        "content": "Explain mixture-of-experts models."
    }]
)

print(response.choices[0].message.content)

import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.FIREWORKS_API_KEY,
  baseURL: "https://api.fireworks.ai/inference/v1",
});

const response = await client.chat.completions.create({
  model: "accounts/fireworks/models/kimi-k3-spot",
  messages: [
    {
      role: "user",
      content: "Explain mixture-of-experts models.",
    },
  ],
});

console.log(response.choices[0].message.content);

curl https://api.fireworks.ai/inference/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $FIREWORKS_API_KEY" \
  -d '{
    "model": "accounts/fireworks/models/kimi-k3-spot",
    "messages": [
      {
        "role": "user",
        "content": "Explain mixture-of-experts models."
      }
    ]
  }'

Pricing

Prices are USD per 1 million tokens. Each Spot rate is 30% below the Standard rate for the same model. A request that falls back to Standard is billed at the Standard rate.

Model	Tier	Cached input	Uncached input	Output
GLM-5.3	Standard	$0.26	$1.40	$4.40
GLM-5.3	Spot	$0.182	$0.98	$3.08
Kimi K3	Standard	$0.30	$3.00	$15.00
Kimi K3	Spot	$0.21	$2.10	$10.50
DeepSeek V4.1 Flash	Standard	$0.006	$0.30	$1.20
DeepSeek V4.1 Flash	Spot	$0.0042	$0.21	$0.84

Availability, retries, and fallback

When no serving capacity is available, the API returns 503. A rate limit returns 429. Honor the Retry-After header when the response includes one. The Fireworks Python SDK retries these errors automatically, up to 2 times by default. Fireworks does not fall back to Standard. See Reliability and Error Handling for timeouts and backoff patterns. If Spot is still unavailable after those retries, send the same request to the Standard model identifier:

from fireworks import Fireworks, InternalServerError, RateLimitError

client = Fireworks()
messages = [{"role": "user", "content": "Explain mixture-of-experts models."}]

try:
    response = client.chat.completions.create(
        model="accounts/fireworks/models/kimi-k3-spot",
        messages=messages,
    )
except (RateLimitError, InternalServerError):
    response = client.chat.completions.create(
        model="accounts/fireworks/models/kimi-k3",
        messages=messages,
    )

print(response.choices[0].message.content)

For a streaming request, fall back only if it fails before the stream starts. Replaying a stream that has already produced output can duplicate that output.

Get Started

Serverless Inference

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Training

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Training API

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Security & Compliance

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Reference

Models

Make a request

Pricing

Availability, retries, and fallback

​Models

​Make a request

​Pricing

​Availability, retries, and fallback

Models

Make a request

Pricing

Availability, retries, and fallback