Meta Launches Paid AI Coding Service 'Muse Code,' Expands Into Developer Market
Meta has launched its paid artificial intelligence (AI) coding service, Muse Code, marking the company’s entry into the developer market.
On Aug. 5, Meta unveiled its latest Muse Spark 1.2 model alongside Muse Code, an AI coding agent. Muse Spark 1.2 is an updated version of the previous model optimized for software development tasks. According to Meta, the model was trained with significantly increased compute resources and a broader range of training environments, improving its capabilities in code generation, complex debugging and codebase comprehension.
While Muse Spark is a general-purpose model, Muse Code is a standalone terminal-based AI coding agent tool. Meta said it trained Muse Spark 1.2 and Muse Code together. Muse Code, the company’s first AI coding agent, is powered by the latest Muse Spark 1.2 model and has been released in beta for macOS and Linux.
One notable aspect of the announcement was the complete absence of references to open source. The shift is unusual for Meta, which has positioned itself as a leading advocate of open AI ecosystems in recent years.
Whereas the company previously pursued indirect monetization through the expansion of the open ecosystem around its open-weight Llama models, Muse Code represents an attempt to generate revenue directly from an in-house business.
Meta highlighted several technical features of Muse Code, including autonomous development workflows, persistent asynchronous background agents and local event logs.
An autonomous workflow feature allows the system to handle planning, coding, testing and result verification in a single process after receiving a user request—a standard capability among advanced AI coding tools. However, persistent asynchronous background agents represent Meta's key strategic move as a late entrant to the AI coding market.
Persistent background agents distribute workloads across multiple AI agents operating simultaneously in the background during a development session. While most competing AI coding tools also support background agents, those systems typically create new helper agents for each task.
In contrast, Muse Code keeps specialized background agents continuously active (warm) throughout an entire session. According to Meta, maintaining agents in a warm state rather than creating them for individual tasks helps avoid redundant information gathering.
This feature could significantly address practical inefficiencies in code development, as creating a new sub-agent for every task forces the system to repeatedly reread the same files.
Under this feature, large-scale tasks are distributed and processed in parallel by sub-agents operating within isolated Git worktrees. This architecture preserves the advantages of parallel execution while preventing state contamination, such as file deletion or modification by other agents on the same files.
Generally, a Git repository has only one working directory, but a Git worktree is a Git feature that enables multiple separate directories—each checking out different branches—to share a single repository (.git history) simultaneously. Each sub-agent operates within its own worktree (an independent directory with an independent branch), ensuring physical isolation from file changes made by other agents. Once work is complete, branches can be merged sequentially, confining conflict management strictly to the integration phase.
Although the technology itself is not new, many products still process subtasks sequentially within a single worktree or rely on file locking and execution ordering for parallel processing. Adopting worktree isolation as a core architecture increases implementation complexity and cost, requiring branch creation and management, merge strategies, conflict handling and cleanup logic.
For that reason, technology media outlet VentureBeat praised Meta’s decision to offer the architecture as a built-in capability at the harness level, despite its relatively limited adoption across the industry.
Meta also highlighted its local event log system, which records model calls, tool usage, approvals and code edit histories to enable task resumption even after crashes. The append-only event log allows developers to replay their entire work history from start to finish to resume work following a failure. This substantially resolves operational issues and serves as a foundation for audit trails.
Overwrite-style event logs make it impossible to determine prior actions, the process taken to reach the current state, or pending tasks. In contrast, foreign media outlets have praised Muse Code's append-only event log system for preserving the entire history sequentially for reconstruction at any time. This forms the foundation for developer efficiency, operational problem-solving, failure recovery and root-cause analysis (RCA) audit trails.
However, Muse Code does have weaknesses. First, its initial release is restricted to a terminal interface. Competing products such as Anthropic’s Claude Code offer terminal, IDE, desktop and web interfaces, while OpenAI’s Codex is supported across CLI tools, IDE extensions and cloud services.
Meta also released benchmark results comparing Muse Spark 1.2 and Muse Code against competing AI models, including Grok 4.5, Claude Opus 5, GPT-5.6 Terra and Gemini 3.6 Flash. The choice of comparison models sparked controversy, as Meta avoided top-tier models from competitors in favor of second-tier options.
According to Meta, Muse Spark 1.2 and Muse Code (harness) achieved a score of 82.9% on Terminal Bench 2.1, narrowly outperforming OpenAI’s GPT-5.6 Terra and Codex at 81.8% and SpaceX (xAI)’s Grok 4.5 and Grok Build at 81.6%. However, it trailed Anthropic’s Claude Opus 5 and Claude Code, which scored 86.7%.
On the Deep SWE 1.1 benchmark, Muse Spark 1.2 ranked behind Claude Opus and OpenAI GPT-5.6 Terra. This drew criticism from the developer community, with some arguing that the system would show lower performance when compared against GPT-5.6 Sol.
AI tech news site Kingy AI further claimed that Meta’s reported benchmark scores were slightly higher than actual verified figures, publishing a side-by-side comparison between Meta’s claims and verified evaluation scores.
The timing of the announcement has also raised suspicion. Muse Code was unveiled less than a month after the release of Muse Spark 1.1. Observers interpret this as an attempt by Meta to regain momentum after Moonshot AI’s Kimi K3 stole the spotlight with overwhelming performance immediately following the ambitious Muse Spark 1.1 launch.
Despite these concerns, Muse Code’s pricing structure is viewed as a major advantage that offsets doubts about its market positioning. Meta is attempting to compensate for its late entry into the coding tool market with an aggressive pricing policy.
Critics note that the pricing strategy is more disruptive than the technology itself. Under the Standard Tier, Muse Spark 1.2 API access for Muse Code costs $1.25 per million input tokens and $4.25 per million output tokens, with cached inputs priced at $0.15 per million tokens. Meta also pledged not to use prompts or generated outputs for model training.
A second pricing option, the Contributor Tier, is available at just $0.10 per million input tokens and $0.20 per million output tokens. In exchange, developers must allow Meta to use their code for future model training.
Financial pressure appears to be driving this aggressive pricing strategy. While Meta reported second-quarter revenue of $60.8 billion, up 28% year over year, operating income fell 8% to $18.8 billion, and operating margin declined from 43% a year earlier to 31%. Capital expenditures (CAPEX) reached $31.08 billion for the quarter alone, with full-year guidance reaching up to $145 billion.
Meanwhile, entering the developer market effectively means entering the enterprise market. Alexander Wang, chief AI officer (CAIO) of Meta Superintelligence Labs and head of Muse Code development, emphasized the product's enterprise capabilities, noting that requests for Zero Data Retention (ZDR) features have already begun arriving. Remarks from CAIO Alexander Wang suggest that ZDR is currently implemented in Muse Code as an optional capability available to enterprises upon request.
ZDR is an agreement where the AI service provider immediately deletes user inputs (prompts) and outputs (responses) from servers upon completion of API call processing, storing them in no form whatsoever. While the Standard Tier already includes a commitment not to use prompts and data for training, ZDR goes one step further.
Under standard tiers, logs are temporarily stored on servers for a set period before deletion, whereas ZDR prevents storage entirely from the outset, eliminating risks associated with data leaks, hacking or future legal disputes. This is essential for regulatory compliance and intellectual property (IP) protection, both of which are major hurdles for enterprise adoption of AI coding tools.
Organizations handling sensitive source code representing trade secrets or operating under strict legal requirements regarding data retention on third-party servers demand ZDR capabilities. Without ZDR, deployment in highly regulated industries remains difficult regardless of model performance, making the feature an essential requirement for AI models and coding tools targeting the enterprise market.