Forethought vs Sierra

Forethought and Sierra both sell AI agents that resolve customer conversations instead of deflecting them, and both serve large companies with high support volumes. Buyers compare them because they cover similar ground at the front door. They come from different directions: Forethought is a support operations suite now inside Zendesk, and Sierra is a platform for building a branded agent that represents your company everywhere customers reach you.

Forethought vs Sierra at a glance

Forethought builds a multi-agent system for customer support and is now part of Zendesk, which announced the acquisition in March 2026. Solve resolves conversations across chat, email, voice, Slack, and API. Triage classifies and routes tickets, Discover finds knowledge gaps, a QA agent scores human tickets, and Assist is a copilot for human agents. By 2025 it supported more than a billion customer interactions a month, for customers like Upwork, Grammarly, Acorns, and Carta.

Sierra is a platform for branded, customer-facing AI agents. Ghostwriter, its agent-building agent, creates multilingual, multichannel agents from SOPs, transcripts, or plain English. Agent Studio manages them, Context Engine brings in customer data, and Insights analyzes performance. Agents run across chat, SMS, WhatsApp, email, voice, and ChatGPT. Customers include Vanguard, Rocket Mortgage, SoFi, Ramp, Chime, and Uber.

Product scope

Forethought. Broad inside the support operation. Beyond resolving conversations, it routes tickets, scores human agents, surfaces knowledge gaps, and assists agents in the helpdesk. It suits support leaders who want AI across the whole queue, human and automated.

Sierra. Broad across the customer experience. The focus is one agent that carries your brand's voice across every channel, with tooling to build and improve it with or without engineering support.

Financial services and compliance

Forethought. Serves fintechs including Acorns, Carta, and YNAB, with use cases like KYC questions and payment tracking. It holds ISO 27001 and SOC 2 Type II, is HIPAA, GDPR, and CCPA compliant, runs on AWS, and redacts PII, PHI, and financial records during ingestion.

Sierra. Financial services is a flagship vertical, with card and account support, fraud, and dispute use cases and customers like Vanguard, SoFi, Ramp, Brex, and Fiserv. It lists SOC 2, ISO 27001, ISO 42001, HIPAA, GDPR, PCI DSS, and FedRAMP, and keeps PII encrypted and masked.

Platform direction

Forethought. Now on the Zendesk roadmap. Zendesk says it will keep supporting existing customers and integrate Forethought into its AI products. For Zendesk shops that should mean tighter integration over time; teams on other helpdesks should ask how the standalone product will evolve.

Sierra. An independent platform that connects to your customer data through its Context Engine and deploys to channels including ChatGPT.

Building and improving agents

Forethought. Agents learn from your existing support data and knowledge base. Discover points out where knowledge is missing, and the QA agent scores human tickets, so the suite improves both the AI and the human team.

Sierra. Ghostwriter builds agents from SOPs, transcripts, or a plain-English description, and Agent Studio is where teams manage them. Insights and Explorer show how agents perform, and Horizon targets long-horizon planning and outcome optimization.

Pricing

Forethought does not publish prices. Its pricing page describes a blend of platform access fees and an outcome-based cost, across Team, Professional, and Enterprise tiers.

Sierra does not publish prices. It describes outcome-based pricing, so you pay for the value its agents deliver, quoted through sales.

Where Runtime fits

Both are built for the customer conversation. In financial services, the hard tickets are about money: a payout that never arrived, a charge that posted twice, an account under review. Resolving them takes work by other teams. A single stuck payment touches four teams: support gets the ticket, payment ops traces it, finance sees a recon break, and risk or compliance may review it. Each investigates separately in different tools.

Runtime is the AI agent harness for those teams. Support, payment ops, finance, risk, and compliance build agents from their SOPs on one platform, so that stuck payment becomes one investigation with one record. Agents run on isolated computers in your own AWS, GCP, or Azure account, or fully self-hosted, use the models you choose, and reach the ledger, processor, bank files, and portals with no API. They pause for approval before anything moves money, and every run is exportable for your sponsor bank or examiner. Runtime runs alongside Forethought or Sierra: they talk to the customer, Runtime works the case behind it.

Which should you choose

• Choose Forethought if you want a full AI suite inside support, including triage, QA, and agent assist, and especially if you run Zendesk.
• Choose Sierra if you are a large consumer brand that wants one branded agent across every channel, with PCI DSS and FedRAMP on the certification list.
• Choose Runtime if your tickets lead into payment ops, finance, and risk investigations, and you want agents for those teams in your own cloud with approvals before money moves.

Frequently asked questions

What is the difference between Forethought and Sierra?

Forethought is a multi-agent support suite covering resolution, triage, QA, knowledge insights, and agent assist, and is now part of Zendesk. Sierra is a platform for building branded customer-facing agents across chat, SMS, WhatsApp, email, voice, and ChatGPT, with Ghostwriter to build agents from SOPs and transcripts.

Which is better for financial services, Forethought or Sierra?

Sierra lists more large financial services customers, including Vanguard, Rocket Mortgage, SoFi, Ramp, and Chime, and lists PCI DSS and FedRAMP among its certifications. Forethought serves fintechs such as Acorns, Carta, and YNAB, and holds SOC 2 Type II, ISO 27001, and HIPAA compliance.

Is Forethought still available after the Zendesk acquisition?

Zendesk announced the acquisition in March 2026 and said it will continue to support Forethought's existing customers while integrating the technology into its own AI products.

How are Forethought and Sierra priced?

Neither publishes prices. Forethought describes a blend of platform fees and an outcome-based cost across Team, Professional, and Enterprise tiers. Sierra describes outcome-based pricing. Both quote through sales.