AI Agent Index
ByHeather MacAvelia·Last verified Jun 20, 2026
Sierra logo

Sierra

4.4/ 5

by Sierra

✓ Verified Review
Visit sierra.ai

Enterprise AI agent platform with governance controls for high-stakes customer interactions. Used by ADT, SiriusXM, Sonos, WeightWatchers. FedRAMP High certified. Custom enterprise pricing.

From

Custom

custom

GitHub

Stars

G2

4.4 / 5

14 reviews ↗

MCP

No

Compatible

Sierra is an enterprise AI customer service platform co-founded in 2023 by Bret Taylor (former Salesforce co-CEO, co-creator of Google Maps, and OpenAI board chair) and Clay Bavor (18-year Google veteran who led Google Labs, Lens, and Workspace). Sierra builds purpose-built conversational AI agents that handle complex, multi-turn customer service interactions autonomously across voice, chat, and digital channels, connecting directly to CRMs, order management systems, subscription platforms, and data warehouses to complete real actions rather than just answer questions. As of Q2 2026, Sierra has raised $1B+ in total funding at a $15B+ valuation and reports $150M+ ARR, with the first $50M quarter delivered in February 2026. Sierra serves 40% of the Fortune 50. Half of its customers have revenue exceeding $1B and one in four exceeds $10B. Deployed by ADT, SiriusXM, Sonos, WeightWatchers, Rocket Mortgage, SoFi, Casper, Chipotle, Prudential, Cigna, and Blue Cross Blue Shield. The $950M Series E round closed May 4, 2026, led by Tiger Global and GV, more than tripling Sierra's valuation from $4.5B just 18 months earlier. Ghostwriter, launched March 25, 2026, lets enterprise teams upload SOPs, call transcripts, whiteboard photos, or audio recordings, or describe a goal in plain English, and produces a production-ready agent across voice, chat, and email in 30+ languages without requiring engineering resources to configure from scratch. Native integrations include Salesforce, ServiceNow, and Zendesk, with custom API connectors for order management systems, subscription billing platforms, and data warehouses. Sierra does not publish a connector marketplace or pre-built integration library. Deployments outside the core Salesforce and ServiceNow stack require custom API work scoped during the implementation engagement. No MCP server has been published as of June 2026, which limits tool-calling accessibility for teams building multi-agent orchestration layers on top of their customer service stack. Pricing is outcome-based and fully custom: Sierra charges per resolved outcome rather than per seat or conversation. Year-one total costs are documented at $200K-$350K+ including platform licensing, implementation fees, and usage, with some enterprise deployments exceeding $1M annually at high resolution volumes. No pricing page is published; all commercial terms are negotiated directly. The outcome-based model aligns vendor incentives with resolution success but makes budget modelling difficult before a commercial discussion, since the definition of a resolved outcome and the per-outcome rate are both contract-negotiated terms. Not suitable for SMBs or mid-market teams given minimum commitment levels. Sierra requires dedicated engineering support to configure API connections and map complex customer workflows. Integration changes typically require Sierra's engineering team rather than self-service configuration, and implementation timelines of months are standard. For mid-market teams, Intercom Fin starts at $0.99 per resolved conversation with faster self-serve deployment and a published connector library. Zendesk AI offers outcome-based pricing with a broader self-serve setup path. Teams that need rapid deployment or lack dedicated implementation resources should evaluate both before committing to Sierra's sales process. Current state Q2 2026: Sierra closed a $950M Series E at a $15B+ valuation on May 4, 2026, led by Tiger Global and GV. Sierra achieved FedRAMP High certification on June 10, 2026, the federal security standard for cloud companies working with U.S. government agencies. This adds to an already comprehensive compliance posture: SOC 2 Type II, ISO 27001, ISO 42001, HIPAA, and GDPR. Sierra opened a Toronto office in May 2026 with about a dozen employees and a growing Canadian customer base. No MCP server is published as of June 2026. G2 shows 4.4 stars across 14 reviews, structurally low given the sales-led enterprise model where NDA constraints limit public review volume. Ghostwriter reached general availability in Q1 2026 and is the flagship Sierra product launch of the year. ARR crossed $150M in February 2026, which Sierra describes as one of the fastest trajectories in enterprise software history.

Pricing

custom

Segment

enterprise

Setup

complex

Verified

Jun 20, 2026

Transparency

Quote Only

Contract

Annual Only

Data training

Not Trained

Autonomy

Human Optional

Capabilities

ticket-resolutionautonomousconversation-intelligencemultilingualintent-detectionomnichannel

Pros & Limitations

Editorial assessment

Pros

  • Founded by Bret Taylor (former Salesforce co-CEO and OpenAI board chair) and Clay Bavor (18-year Google veteran): executive credibility and AI research depth that few enterprise platforms can match, reflected in $1B+ raised at a $15B+ valuation and Fortune 50 adoption across 40% of the index
  • Outcome-based pricing aligns vendor incentives with customer success: you pay per resolved interaction rather than per seat or conversation, meaning Sierra has a direct financial stake in resolution quality rather than usage volume
  • Handles emotionally sensitive, multi-turn conversations with natural language quality significantly above standard chatbot platforms: suitable for high-stakes interactions where brand voice consistency and resolution quality are strategic priorities

Limitations

  • Year-one costs run $200K-$350K+ including platform licensing, implementation fees, and usage: among the most expensive AI customer service platforms, positioning it out of reach for all but large enterprises with significant inbound contact volume
  • Outcome-based pricing is difficult to model before deployment: what counts as a resolved outcome requires careful contract negotiation and can create disputes as edge cases emerge in production
  • Integration changes typically require Sierra's engineering team rather than self-service configuration: less documentation and community knowledge than established platforms like Zendesk or Intercom Fin, and implementation typically takes months

Technical Details

Deployment
webapi
Model architectureProprietary
Avg setup time4-8 weeks for enterprise deployment (custom AI persona configuration, integration, and testing)
Autonomous rateResolves common queries end-to-end across chat, email and voice without human escalation
Integrations
SalesforceServiceNowZendeskCustom APIs
Security
SOC 2 Type IIISO 27001ISO 42001HIPAAGDPRFedRAMP

Similar agents

Rating

4.4/ 5

Editorial score

How we score this →

Score breakdown

AutCap 5 · IntDepth 5 · PriceTrans 2 · IndEvid 4 · SetupAcc 2 = 4.40

Industries

EnterpriseB2BSaaSeCommerce

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