Is Muse Spark 1.3 free on OpenCode, and what do you get for $10 a month?
Yes, as Muse Spark 1.3 Contributor Free on OpenCode Zen, free for a limited time. On the $10-a-month Go plan the Contributor model carries a $60 monthly usage limit, an estimated 226,600 requests.
Checked against the lab's own pages on September 19, 2026. Limits change often, so the date matters.
Muse Spark 1.3 is free on OpenCode at the moment, listed as Muse Spark 1.3 Contributor Free. OpenCode's Zen pricing table puts Free in every price column for it, and the note underneath says it's there "for a limited time".
- Free tier
- Muse Spark 1.3 Contributor Free, for a limited time
- Go subscription
- $10/month
- Monthly limit on Go
- $60 of usage
- Five-hour limit
- 20% of the monthly limit
- Estimated requests a month
- 226,600
- Data
- Prompts and completions train future Meta models
What the free tier costs you
The Contributor models trade money for data. OpenCode's page says the heavily discounted token pricing is "in exchange for permission to use your prompts and completions to train future Meta models", and that availability is limited to regions permitted by Meta's Geographic Use Policy. In the Go privacy table, the Contributor rows are the only ones marked Yes under model training, and their retention reads "Not ZDR".
What $10 a month buys
OpenCode Go is a $10/month subscription. On it, Muse Spark 1.3 Contributor runs $0.10 per million input tokens and $0.20 per million output, with a $60 monthly usage limit.
That limit is a dollar figure rather than a message count, and OpenCode splits it the same way for every model: the five-hour limit is 20% of the monthly limit and the weekly limit is 50%. On a $60 model that works out to $12 in any five hours and $30 in a week.
OpenCode's own estimate for this model is 45,300 requests per five hours, 113,300 a week and 226,600 a month. That assumes 620 input, 71,400 cached and 300 output tokens per request, which it says is typical Go usage.
If you reach the usage limit, you can continue using the free models.
Zen without the subscription
Zen is pay-as-you-go, and full-price Muse Spark 1.3 there is $1.25 per million input tokens and $4.25 per million output. That's where the Contributor discount shows: more than twelve times cheaper on input, in return for the training permission.
If you run out on Go and you hold a Zen balance, the console has a Use balance option that lets Go fall back to that balance instead of blocking requests.