# Muse Spark 1.3 (Contributor)

Muse Spark 1.3 (Contributor) is a text generation model from Meta, available through the Impossibl API. Its published context window is 1,048,576 tokens. The advertised input rate is $0.10 per million input tokens. The advertised output rate is $0.20 per million output tokens.

- Model identifier: ` meta/muse-spark-1.3-contributor `
- Creator: Meta
- Model type: Text generation
- Canonical model page: [Muse Spark 1.3 (Contributor)](<https://impossibl.com/meta/muse-spark-1.3-contributor>)
- API availability: Listed as serving through Impossibl.
- Creator release date: 2026-09-02

## Capabilities and limits

- 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 ` meta/muse-spark-1.3-contributor ` 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 An unpublished rate is unknown, not zero.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 | $0.10 | per million input tokens |
| Output | $0.20 | per million output tokens |
| Cache read | $0.002 | 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 Muse Spark 1.3 (Contributor)?

Muse Spark 1.3 (Contributor) is a text-generation model from Meta, available through the Impossibl API.

### How much does Muse Spark 1.3 (Contributor) cost?

Muse Spark 1.3 (Contributor) costs $0.10 per million input tokens and $0.20 per million output tokens through the Impossibl API. Cache reads cost $0.002 per million tokens. All rates are in USD.

### What is the context length of Muse Spark 1.3 (Contributor)?

Muse Spark 1.3 (Contributor) has a 1,048,576-token context window through the Impossibl API.

### What inputs and outputs does Muse Spark 1.3 (Contributor) support?

Muse Spark 1.3 (Contributor) accepts text and image as input. Muse Spark 1.3 (Contributor) returns text.

### How do I use Muse Spark 1.3 (Contributor) through an API?

Muse Spark 1.3 (Contributor) is available through the Impossibl API. Use meta/muse-spark-1.3-contributor as the model identifier with /v1/chat/completions. The quickstart explains how to create an API key and send your first request.

### When was Muse Spark 1.3 (Contributor) released?

Meta released Muse Spark 1.3 (Contributor) on September 2, 2026.

Sources: [Creator release announcement](<https://vercel.com/changelog/muse-spark-1-3-now-available-on-ai-gateway>)

## 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>)
- [Muse Spark 1.3 (Contributor): model details and pricing](<https://impossibl.com/meta/muse-spark-1.3-contributor>)
- [Model directory](<https://impossibl.com/models>)