Bret Taylor’s Sierra buys YC-backed AI startup Fragment

TechCrunch / 4/24/2026

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Key Points

  • Sierra(Bret Taylorが創業したカスタマーサービス・エージェント企業)が、YC支援のフランス企業Fragmentを買収したと発表しました。
  • Fragmentは、ビジネスがAIを業務フローに統合するための支援を行っており、共同創業者のOlivier MoindrotとGuillaume GenthialがSierraに加わります。
  • 今回はSierraにとって3回目の公開買収で、直近では日本のOpera Techや音声エージェントのReceptive AIも相次いで買収しています。
  • 条件(買収金額など)は明らかにされておらず、PitchBookはFragmentがシードラウンドで約200万ドルを調達したと推定しています。
  • SierraはOpenAIの取締役会議長を務めるTaylorが関与し、これまでに累計約6.3億ドルの資金調達と10億ドル規模の評価額を背景に成長を続けています。

Sierra, the customer service agent startup founded by Bret Taylor, announced on Thursday that it has acquired the YC-backed French startup Fragment, which helps businesses integrate AI into workflows. 

This is Sierra’s third public acquisition. It previously bought Japan-based enterprise AI solutions company Opera Tech (which it acquired in late March) and voice agent company Receptive AI (which it also announced it acquired in late March). Fragment co-founders Olivier Moindrot and Guillaume Genthial will be joining the Sierra team. 

In a blog post, Taylor and his co-founder, Clay Bavor, wrote that Moindrot and Genthial will bring “valuable strength” to Sierra’s “agent development efforts in France.” Terms of the deal were not announced. PitchBook estimates that Fragment raised around $2 million through its seed round.

Taylor, who also serves as OpenAI’s chairman of the board, co-founded Sierra alongside Google alum Bavor after stepping down as co-CEO of Salesforce in early 2023. The startup claims Casper, Clear, and Brex as customers and has raised more than $630 million in funding to date, from investors including Sequoia and Benchmark, giving it a $10 billion valuation.