Muse Code exits beta with SDK and subscriptions

Muse Code, Meta’s terminal coding agent, is out of beta less than a month after its August 5 debut. It now has three flat monthly plans at $5, $15 and $50, where usage rises in step with the price, The New Stack reported on September 1.

Muse Code runs on Meta’s Muse Spark 1.2 model and competes with Claude Code and Codex. The plans are Everyday Usage at $5 a month, High Usage at $15 with three times the usage, and Power Usage at $50 with 10 times the usage. Meta says the $5 plan typically covers around 10 to 50 requests every five hours, depending on how complex the work is. The pay-as-you-go options from the beta stay available alongside the plans.

Anthropic includes Claude Code in its $20 Pro plan, and its $100 Max 5x and $200 Max 20x plans give five and 20 times Pro’s per-session usage. OpenAI uses the same structure: Codex comes with the $20 Plus plan, and the $100 and $200 Pro tiers give five and 20 times Plus usage. Meta’s most expensive plan costs half of either rival’s $100 tier.

What those plans actually buy is harder to compare. Anthropic publishes no absolute prompt counts for Pro, Max 5x or Max 20x. It describes the Max allowances only as multiples of Pro, with five-hour session limits and weekly limits on top. OpenAI’s estimate for GPT-5.6 Sol is 10 to 100 local Codex messages every five hours on Plus, 50 to 500 on Pro 5x and 200 to 2,000 on Pro 20x, and it says model, task complexity, context, reasoning and tools all affect the real number. So Meta’s 10-to-50 figure doesn’t line up neatly against any of them.

Muhammad Navaid, a senior machine learning engineer, liked the proportional structure. “After all the Claude and ChatGPT usage-limit drama, this is refreshingly simple,” he wrote on LinkedIn, a week after OpenAI brought back the five-hour window for Plus accounts. “And honestly, this is how AI coding subscriptions should work.”

The pay-as-you-go pricing was what drew criticism at launch. The Standard tier charges $1.25 per million input tokens and $4.25 per million output tokens. The Contributor tier charges $0.10 and $0.20, but Contributor users agree that their prompts and completions can be used to improve Meta’s products. Several engineering leaders told The New Stack at the time that this trade-off rules the tier out for proprietary code. Ashok Gelal, co-founder and CEO of Msty AI, called the new subscription prices “unbelievably low” and then went back to the data question on X: “The biggest concern here is Meta itself.”

Per-token price also leaves out how many tokens a task takes. Jessica Wachtel of The New Stack ran Muse Code and Claude Code on the same three coding tasks. Muse Code cost much less but used substantially more tokens, did worse on a refactoring task and left dead code behind on another.

The launch also adds features. Inter-session messaging lets separate Muse Code sessions share context and state when their work overlaps. Workflows builds on the existing multi-agent setup: it coordinates teams of specialized agents across larger jobs, passes intermediate work between stages and returns one result at the end. Developers can watch and steer those agents from a Workflows control room. A rewind feature rolls both the conversation and the code changes back to an earlier point in a session. All of this sits on top of the asynchronous background agents from the beta, which stay active through a session to gather information for the main agent.

The SDK, in developer preview, takes Muse Code beyond the CLI. Your own code can start and resume sessions, send instructions, handle responses and react to what the agent does, so it can back anything from IDE integrations to standalone agent products. Mark Zuckerberg said on X that the aim is to let developers build their own agents on Muse Code: “Embed them in your apps, connect custom tools, stream progress, and resume sessions later.” Anthropic’s Claude Agent SDK and OpenAI’s Codex SDK already do the same for their agents.

Meta has also published the Muse Session Protocol (MSP), which external clients use to talk to Muse Code sessions. Developers can use Meta’s TypeScript SDK or implement MSP directly in another language.