Customer Experience AI Agent agents
Supported Supported Supported Supported Partial support
Sierra
4.5(45 G2 reviews)San Francisco, USAFounded 2023
Enterprise platform to build AI agents that resolve customer service across chat, email, SMS, WhatsApp, voice and ChatGPT, with agent-building tools, analytics and outcome-based pricing.
Overall scoreFive points for every passed standard task. Missing or failed tasks earn zero.
Not evaluated
G2 task evaluationScores based on G2's standardized task evaluation, separate from buyer reviews.
AccuracyNot available
Policy complianceNot available
G2 buyer reviewsAggregate scores reported by verified G2 reviewers. These do not affect the task-based Overall Score.
Ease of use88
Quality of support91
Estimated autonomyA sourced estimate of how independently the agent can plan and complete work on the L1–L5 scale.
Where this agent sits on the L1–L5 autonomy scale.
L3-L4
L1L2L3L4L5
Skills
The five shared skills reviewed for products in this category.
Case Routing & Escalation
Grounded Answers
Policy Compliance
Refunds & Billing
Performance claims
Vendor-reportedResolution rate 80%
Frontier skillsEmerging agent capabilities explicitly documented in reviewed product sources.
Live-call payments end to end (card + ACH, request to confirmation in one call)yes