# Sierra — Bret Taylor’s enterprise agent platform, branded AI agents that resolve customer issues end to end, priced on outcomes.

> Source: The Agents Index — https://theagentsindex.com/sierra (structured, researched, re-verified)
> Facts last verified: 2026-07-24

Sierra is an enterprise conversational-AI platform for customer experience, co-founded by Bret Taylor (former co-CEO of Salesforce and chair of OpenAI’s board) and Clay Bavor (ex-Google). It lets large companies build branded AI agents that resolve customer issues end to end — answering questions, taking actions and completing tasks — across chat, email, SMS, WhatsApp, voice and ChatGPT. Rather than a self-serve tool, it is a managed ‘agent OS’ delivered to enterprises, and has become one of the most prominent names in the category. Founded in early 2024, Sierra has raised roughly $1.585 billion across four funding rounds in under two years — most recently a $950 million round in May 2026 led by Tiger Global and GV that pushed its valuation above $15 billion — and counts SoFi, Ramp and Chime among its customers. On 2026-06-10 it achieved FedRAMP High certification in partnership with Knox Systems, opening the door to the most sensitive US federal government workloads. On 2026-07-16, co-founders Taylor and Bavor announced Horizon, a platform layer for agents that proactively pursue a goal over days, weeks or months — such as originating a loan or securing a healthcare prior authorization — rather than resolving one conversation at a time.

| Fact | Value |
| --- | --- |
| Website | https://sierra.ai |
| Best for | Large enterprises that want branded, autonomous customer agents that resolve issues end to end and are willing to run a managed engagement. |
| Not for | SMBs or developers wanting a self-serve, transparently priced product or an open public API. |

## Verdict

Sierra is the enterprise standard-bearer for customer-experience agents, and the pedigree is real: co-founded by Bret Taylor and Clay Bavor, it reached $150M+ ARR by February 2026, has raised roughly $1.585 billion at a valuation above $15 billion, and is used across more than 40% of the Fortune 50. What sets it apart is depth, agents don’t just answer, they act, completing refunds and account changes across chat, voice, email and more, wrapped in serious tooling for building, supervising and testing them. Its outcome-based pricing (pay for resolutions, escalations free) is a genuinely aligned model. The flip side is access: it is sales-led with no public pricing, no free tier and a gated SDK, so it is neither quick to trial nor a fit for smaller teams. Pick Sierra if you are an enterprise that wants autonomous agents doing real work; skip it if you need self-serve, transparent pricing or an open API.

## Strengths and weaknesses

- ✓ Resolves issues end to end with real actions across every channel, with strong enterprise proof — $150M+ ARR by February 2026 (up from $100M in November 2025) and named customers including SoFi, Ramp and Chime.
- ✓ Outcome-based pricing aligns spend with value delivered — you pay for resolutions, and human escalations are free.
- ✓ Exceptionally well-capitalized for the category: raised $950M in May 2026 (led by Tiger Global and GV) at a valuation above $15 billion, bringing total funding to roughly $1.585B across four rounds since its early-2024 founding.
- ✓ Federal-grade credibility on top of its enterprise base: achieved FedRAMP High certification in June 2026 (in partnership with Knox Systems), opening the most sensitive US government workloads to its platform.
- ✗ Enterprise-only and sales-led: there is no public pricing, no free tier, and no self-serve developer API, the Agent SDK and docs are gated to contracted customers.
- ✗ Outcome pricing is custom-negotiated and can be hard to predict or benchmark, and the platform is overkill for SMBs.
- ⚠ No public sign-up, pricing page or self-serve API, access is via an enterprise sales engagement.
- ⚠ The developer-facing Agent SDK exists but is gated to contracted customers rather than openly available.

## Key features

- **End-to-end resolution** — Agents take real actions — refunds, subscription changes, order lookups — grounded in company policy, not just canned answers.
- **Agent Studio + Ghostwriter** — A visual builder plus a tool that turns SOPs, transcripts or plain English into production-ready, multilingual agents.
- **Omnichannel from one definition** — One agent spans chat, email, SMS, WhatsApp, voice and ChatGPT.
- **Supervision & analytics** — Explorer, Monitors, Experiments and Observability let teams watch behaviour, catch issues and A/B test changes.
- **Horizon (long-horizon agents)** — A platform layer, launched July 2026, for agents that proactively pursue a goal over days or weeks — e.g. originating a loan or securing a healthcare prior authorization — instead of resolving a single conversation.

## Use cases

- **Enterprise support at scale** — A large brand deflects and resolves a high volume of customer conversations autonomously, escalating only edge cases to staff.
- **Post-purchase account actions** — The agent completes refunds, subscription changes and order tracking end to end by acting on connected systems.

## Integrations

Data warehouses — Snowflake, Databricks · Cloud — Google Cloud, AWS · Channels — voice, WhatsApp, SMS, email, ChatGPT · Business systems via connectors (CRM, commerce, order systems) · Model Context Protocol (MCP) — Sierra agents are natively publishable to ChatGPT Apps via MCP

## Sources

- https://sierra.ai
- https://sierra.ai/customers
- https://techcrunch.com/2025/11/21/bret-taylors-sierra-reaches-100m-arr-in-under-two-years/
- https://techcrunch.com/2025/09/04/bret-taylors-sierra-raises-350m-at-a-10b-valuation/
- https://techcrunch.com/2026/05/04/sierra-raises-950m-as-the-race-to-own-enterprise-ai-gets-serious/
- https://sierra.ai/blog/publish-to-chatgpt
- https://sierra.ai/blog/certified-fedramp-high
- https://www.prnewswire.com/news-releases/sierra-achieves-fedramp-high-certification-through-partnership-with-knox-systems-302796965.html
- https://sierra.ai/blog/horizon