About Sierra
Sierra provides an AI agent platform that helps companies deliver personalised customer experiences across chat, SMS, WhatsApp, email, voice, and ChatGPT. The platform enables teams to build, optimise, and scale AI agents quickly with outcome-based pricing.
NeuronScore
Agent-Ready
MCP
Public API
Webhooks
OAuth2
SDK · TS
SDK · Py
Funding History
Sep 2025 Series c — $350M
Sep 2025 Series C — $350M
Oct 2024 Series b Greylock Partners $175M
Oct 2024 Series b — $175M
Feb 2024 Series a — $110M
Feb 2024 Series A — $110M
Team
co-founder & ceo
Co-founder & co-CEO of Sierra. Chairman of OpenAI. Ex-co-CEO Salesforce, ex-CTO Facebook.
co-founder & president
Co-founder & co-CEO of Sierra. 18 years at Google leading AR/VR.
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FAQ
When was Sierra founded?
Sierra was founded in 2023 in San Francisco, United States.
How much funding has Sierra raised?
Sierra has raised $1.3B across 6 rounds — most recently a Series c in Sep 2025.
What is Sierra's valuation?
Most recent disclosed valuation is $10B.
How much does Sierra cost?
Sierra pricing: Enterprise · Contact sales.
Who founded Sierra?
Bret Taylor and Clay Bavor founded Sierra.
Where is Sierra headquartered?
Sierra is headquartered in San Francisco, United States.
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