Billions Invested, Delayed Release: Pressure Mounts on Meta Over Muse Spark API

Slow Rollout Raises Investor Concerns

Meta is facing growing pressure after repeatedly postponing the public release of the API for its newest AI model, Muse Spark. According to the Wall Street Journal, the company has moved the anticipated launch multiple times and currently has no firm date for when developers will gain access. The delay comes at a sensitive moment: Meta has signalled plans to spend up to $145 billion this year largely on AI infrastructure, and investors are watching closely for signs that those outlays will translate into revenue.

Metas AI chief, Alexandr Wang, had suggested a near-term rollout for the Muse Spark API just two months ago, tweeting in April that "the muse spark API will be coming soon!" Developers expressed clear enthusiasm Wang said he was "thrilled" by the interest but the promised availability never materialised. People familiar with the project say technical issues in testing and additional infrastructure requirements pushed an April target to May, and then later to June.

A Meta spokesperson told the Wall Street Journal the company is testing the interface with partners and still aims to release it this month, adding, "We know people want the API, and we look forward to making it available to them."

Strategic Stakes: From Open Source to Proprietary

Muse Spark represents a notable strategic shift for Meta. Earlier generation AI models from the company were released as open-source software and could be downloaded and used freely. Muse Spark, by contrast, is proprietary and will be accessible only via a closed API the central gateway for developers building applications on top of non-downloadable models. Internal performance benchmarks reportedly show Muse Spark can compete with models from OpenAI and Anthropic, and in many tests it outperformed Grok from xAI. Yet only a handful of independent testing bodies have seen the system; the broader developer community remains locked out for now.

That lack of access limits outside validation and slows potential commercial adoption. For Meta, the API is more than a technical product: it is a distribution and monetisation channel. Delays therefore complicate the companys task of demonstrating a path from massive capital investment to recurring revenue.

Meta has signalled several avenues to monetise its AI and other services. The company recently announced paid subscription options for Instagram, WhatsApp and Facebook, and said it will trial paid features for its AI assistant, Meta AI. Mark Zuckerberg also told shareholders that building a cloud business to sell excess compute capacity is on the table. He added that customers ask Meta weekly for a formal AI interface offering, even as he declined to announce a concrete launch date for the Muse Spark API.

Market reaction has reflected investor unease: when Meta disclosed higher-than-expected AI spending in April, the stock fell more than 5% in after-hours trading. At the time this article was published, the Meta Platforms (A) share listed on Tradegate was trading down 0.80% at 533 EUR (June 4, 2026, 11:09 CET).

Conclusion

Metas pause on opening Muse Spark to the wider developer community has become a focal point for investor scrutiny as the company embarks on an unprecedented AI spending program. The coming weeks will be critical: a smooth API launch and early commercial signs of monetisation could reassure markets, while further delays would raise fresh questions about the returns on Metas multibillion-dollar AI bet.