Meta
Operationalยท checked every few minutes

Muse Spark 1.3 Contributor API

The Muse Spark 1.3 Contributor API: Meta's Muse Spark 1.3 at its Contributor tier, where Meta may train on what you send, 60% below Meta's list price

Price per 1M tokens60%off
Input
$0.04$0.10
Output
$0.08$0.20
Cached input
$0.001
Model IDmuse-spark-1.3-contributor
chat.py
from openai import OpenAI
client = OpenAI(
base_url="https://api.zurelay.com/v1",
api_key="YOUR_ZURELAY_KEY",
)
stream = client.chat.completions.create(
model="muse-spark-1.3-contributor",
messages=[{"role": "user", "content": "Explain quicksort in two sentences."}],
stream=True,
)
for chunk in stream:
if chunk.choices:
print(chunk.choices[0].delta.content or "", end="")

Base URL https://api.zurelay.com/v1. Works with any OpenAI SDK. Chat API docs

Context window
1M tokens
Reasoning
minimal to xhigh
Input
Text, Image, PDF
Released
Sep 2, 2026
Status
Operational

Pricing

Muse Spark 1.3 Contributor API pricing. A fraction of the list price.

Pay as you go from prepaid credit, with no subscription. Top up from $10. Requests that fail are never billed.

RateZurelayMeta list
Input
per 1M tokens
$0.04$0.10
Output
per 1M tokens
$0.08$0.20
Cached input
per 1M tokens
$0.001โ€”

One rate at every prompt length, up to the full 1M context window. Streaming, tool calls and structured outputs cost nothing extra.

Savings calculator

Move the sliders to your monthly usage.

Input tokens per month50M
Output tokens per month10M
Zurelay
$2.80
Meta list price
$7.00
You save every month$4.20

$50.40 a year

Overview

What is Muse Spark 1.3 Contributor?

Muse Spark 1.3 Contributor is Meta's Muse Spark 1.3 at Meta's Contributor tier: the same model as standard Muse Spark 1.3 at a much lower price, because Meta may use the prompts and completions sent to this tier to train future Meta models. Don't send it anything private or sensitive; for that, use Muse Wonder, which runs at Meta's standard tier. The Zurelay Muse Spark 1.3 Contributor API serves it through one OpenAI-compatible endpoint with a 1M-token context window, at 60% below Meta's list price.

The Contributor tier is a model attribute, not a different model. Meta's model docs list muse-spark-1.3 in Standard mode, where your content is not used to train Meta models, and muse-spark-1.3-contributor in Contributor mode, where your content may be used to train future Meta models in exchange for a lower price. Meta counts as content the prompts, code, files and context you send and the answers you get back. So use this model only for data you are fine with Meta training on, such as public material and tests; for anything private, confidential or personal, use Muse Wonder (muse-wonder-1.0), a standard-tier model. On Zurelay the model ID is muse-spark-1.3-contributor, and it costs $0.04 per 1M input tokens and $0.08 per 1M output tokens.

Meta released Muse Spark 1.3 on September 2, 2026, as the latest Muse Spark version, tuned for agentic work such as multi-step tool, browser and long-horizon tasks, with better coding than Muse Spark 1.2. Meta says it tracks context and earlier results, works through messy or conflicting inputs, asks clarifying questions when a prompt is ambiguous and confirms before consequential actions. In comparisons by Meta engineers it used about 20% fewer tool calls and 25% fewer tokens than 1.2 on coding work.

In Meta's results for Muse Spark 1.3 at max reasoning, it scores 75.4 on DeepSWE v1.1, ahead of Claude Opus 5 (74.0) and GPT-5.6 Sol (73.0), and 88.8 on Terminal-Bench 2.1, level with GPT-5.6 Sol. On MRCR at 512K to 1M tokens, a long-context test, it scores 98.1 against 73.8 for GPT-5.6 Sol and 55.5 for Muse Spark 1.2. Meta's docs list the max level for standard Muse Spark 1.3 and not for the Contributor tier. These are Meta's numbers, not independent ones.

Muse Spark always reasons before it answers, at a level you choose, with medium as the default, and in our tests it thinks a lot. Reasoning tokens bill as output. On Zurelay it reads text, images and PDFs and writes text, with a context window of 1,048,576 tokens, and it calls tools and returns JSON. Meta lists the Contributor tier at $0.10 input, $0.20 output and $0.002 cached input per 1M tokens, against $1.25, $4.25 and $0.15 for the standard tier. On Zurelay you pay $0.04 and $0.08, with cached input at $0.001.

Strengths

Where Muse Spark 1.3 Contributor shines. And what teams build with it.

01

Muse Spark at a low price

The same Muse Spark 1.3 as Meta's standard tier, for a fraction of the standard price, wherever Meta training on the data is acceptable.

02

Long context that holds up

98.5 on MRCR at 256K to 512K tokens and 98.1 at 512K to 1M in Meta's results at max reasoning, for long documents and long agent traces.

03

Agentic coding

75.4 on DeepSWE v1.1 and 88.8 on Terminal-Bench 2.1 in Meta's results at max reasoning, level with or ahead of Claude Opus 5 and GPT-5.6 Sol on both.

04

Images and PDFs

Reads screenshots, photos, scanned pages and PDFs next to your text in one 1,048,576-token context.

Use cases

  • Prototypes and tests

    Meta pitches Contributor mode for prototyping, testing integrations and scaling experiments where it is acceptable for Meta to train on the content.

  • Work on public data

    Research, summaries and analysis over public web pages, open-source code and published documents, where nothing is private.

  • Sub-agents and tool loops

    Meta suggests Muse Spark for high-volume, cost-sensitive work such as sub-agent tasks, classification and tight tool loops.

  • Long public documents

    Questions over long public reports, filings and PDFs held in one 1M-token context.

Get started

Call Muse Spark 1.3 Contributor in three steps.

No waitlist and no new SDK. If your code already talks to OpenAI, it already talks to Zurelay.

  1. 1

    Create a key

    Sign up, add credit and create an API key. Set a monthly budget or a rate limit per key if you like.

  2. 2

    Point your SDK at Zurelay

    Change the base URL. Everything else in your code stays the same.

    https://api.zurelay.com/v1
  3. 3

    Use muse-spark-1.3-contributor

    Send chat completions as usual. Streaming, tool calls and usage reporting work as you expect.

    muse-spark-1.3-contributor

FAQ

Muse Spark 1.3 Contributor API questions.

Anything else? Ask our team and weโ€™ll answer by email.

Does Meta train on what I send?

It may. Muse Spark 1.3 Contributor is Meta's Contributor tier, and Meta's docs say that content sent to it, meaning your prompts, code, files and context and the answers you get back, may be used to train future Meta models, in exchange for the lower price. At Meta's standard tier, content is not used to train Meta models. So don't send this model anything private, confidential or personal, or anything you have promised others to keep private. For that work, use Muse Wonder (muse-wonder-1.0), which runs at Meta's standard tier.

How much does the Muse Spark 1.3 Contributor API cost?

On Zurelay, muse-spark-1.3-contributor costs $0.04 per 1M input tokens and $0.08 per 1M output tokens, with cached input at $0.001. Meta's Contributor-tier price is $0.10 input and $0.20 output per 1M, so you save 60%. The rate is the same across the whole context window, and reasoning tokens bill as output.

What is the difference between Muse Spark 1.3 and Muse Spark 1.3 Contributor?

Meta runs the same model at both tiers. The difference is data use and price: Meta may train future models on what you send to the Contributor tier and doesn't at the standard tier, and the Contributor tier costs far less, $0.10 input and $0.20 output per 1M tokens on Meta's list against $1.25 and $4.25. Meta's docs also keep the extended max reasoning level for the standard tier.

How do I call the Muse Spark 1.3 Contributor API with the OpenAI SDK?

Install the official openai package, set base_url to https://api.zurelay.com/v1 and use your Zurelay API key. Then send a Chat Completions request with model set to "muse-spark-1.3-contributor"; Zurelay also accepts meta/muse-spark-1.3-contributor and muse-spark-1-3-contributor. Images go in image_url parts and PDFs in file parts.

What is the Muse Spark 1.3 Contributor context window?

1,048,576 tokens. On Zurelay it reads text, images and PDFs and writes text. Meta lists audio and video input for Muse Spark too, but Zurelay doesn't take them for this model: a request that includes one is turned away with a clear error before anything is billed.

How do Muse Spark 1.3 Contributor reasoning levels work?

The model always reasons before it answers. Set reasoning_effort to minimal, low, medium, high or xhigh; medium is the default. none isn't offered, and a request for none runs at minimal. Meta keeps the extended max level for standard Muse Spark 1.3, so a request for max runs at xhigh on this tier. In our tests it thinks a lot, and its thinking counts toward max_tokens: if the limit runs out while it is still thinking, the answer comes back empty, so leave room, a few thousand tokens for hard questions.

Can I force Muse Spark 1.3 Contributor to call a tool?

Yes. It calls tools you define, and Meta's API only takes tool_choice "auto". So when you send "required" or a named function, Zurelay sends auto, offers only the tool you named and tells the model to call it; for "none", it tells the model to answer in text.

Does Muse Spark 1.3 Contributor support JSON output and stop sequences?

It returns JSON when response_format asks for json_object or json_schema. Stop sequences have no effect: Meta's API ignores stop, so the answer runs to its natural end, and you can cut it in your own code if you need to.

Is it the same model as Meta's Muse Spark 1.3?

Yes. Requests go to Meta's muse-spark-1.3-contributor, which Meta runs as the same model as muse-spark-1.3, at the Contributor tier. Zurelay doesn't swap in a different model. Only smart routing, which you turn on yourself, can answer with a close alternative when the model is down, and the x-zurelay-model header names the model that answered. Responses are sampled, so wording varies between runs. Zurelay is independent and is not affiliated with or endorsed by Meta.

More models on Zurelay

All models

Stop paying list price.
Start saving today.

Create a key in seconds, point the SDK you already use at Zurelay, and every request costs up to 90% less from the first token.