Runtime vs Sierra

Sierra is the better fit if the main job is a branded AI agent talking to customers across chat and voice. Runtime is the better fit if the hard part is the work behind the conversation, such as tracing a payout or working a recon break, across every team that touches a transaction and in your own cloud. Runtime is the AI agent harness for payment and fintech teams.

Sierra and Runtime at a glance

Sierra builds conversational AI agents for customer experience. Large consumer brands use its agents to talk to customers across chat and voice, take actions in their systems, and resolve requests, with outcome-based pricing.

Runtime is an agent harness for payment teams. From payment ops to risk, compliance, and support, anyone on the team can build agents that work their queues on their own computers inside your cloud, called from Slack, Teams, email, SMS, or voice, with approvals and a full audit trail.

Sierra is for consumer brands that want a branded agent talking to customers. Runtime is for fintech operators who need agents behind the conversation, in every team that touches a transaction.

How they differ

Front of house or back office

Sierra is focused on customer experience: the conversation, the brand, and the resolution. Runtime is focused on the investigations behind the conversation, for support and for the payment ops, finance, risk, and compliance teams that support hands work to.

Where it runs and which models

Sierra is a hosted platform with vendor-managed models. Runtime runs agent computers in your AWS, GCP, or Azure account, or fully self-hosted via Helm. You bring your own models, including open-weight models served in your cloud for PCI and PII work, with routing and fallbacks when a provider goes down.

Approvals on money movement

Back-office agents need different guardrails than a chat agent. Runtime agents start read-only and ask a person before releasing a payout, applying a reserve, or replying to a sponsor bank. Every run is recorded end to end and exportable for an auditor or examiner.

Where Runtime enters the picture

In payments, the customer conversation is often the easy part. A merchant writes in that yesterday's payout is missing. Support gets the ticket, payment ops traces the payout at the processor, finance sees a recon break when the settlement file doesn't match the ledger, and risk or compliance may check whether a hold was applied on purpose. A customer-facing agent can acknowledge the question, but the four teams still investigate it separately, in four tools. On Runtime it's one investigation with one record, and the answer goes back to the customer through whichever channel you use, including Sierra.

Most teams start with one queue, often the "where's my payout" tickets that support escalates to payment ops. Once that agent works, the same harness and shared memory carry over to finance's recon breaks and risk's reviews, and the platform grows to every team. Rain replaced $250k in vendor spend with Runtime.

• No single vendor to depend on. Agents run in your AWS, GCP, or Azure account or self-hosted, on any sandbox provider with fallbacks, and on Claude, GPT, Gemini, or open-weight models, routed across Claude Code, Codex, and OpenCode. An outage at one provider doesn't stop the back office.
• Guardrails you set. Agents start read-only, credentials are masked, card numbers and SSNs are stripped from prompts and logs, and role-based access decides which team sees what.
• Built for teams. Support, payment ops, finance, risk, and compliance share agents, templates, and one memory, so the payment ops agent knows what support already found.
• An engineer, not an account executive. A forward-deployed AI engineer who built payment systems at Hulu's payments team at Disney, Finix, Modern Treasury, or BlackRock starts with your sharpest queue and builds the first agents with your team.

Describe the jobConnect your tools, even legacy onesKeep a human in the loopNo single vendor to depend onOne memory across teamsEvery run is stored

[::]New agent

Create a banking ops agent that handles RFIs, hold-harmless requests, and returns of funds from our partner bank, verifies against our ledger, and drafts replies for my approval.

Describe the agent you want

Agent ready

bank-ops-agent

Tools picked from your prompt

EmailLedgerSFTPMastercard

Where Sierra is stronger

• Customer-facing agents at consumer scale. Its core strength, used by large consumer brands.
• Branded experience. Agents designed to represent your brand in chat and voice.
• Outcome-based pricing. You pay for resolutions rather than seats.
• Focus on CX. Everything in the product is built for customer experience teams.

Which should you choose

Choose Sierra if

• You need a branded, customer-facing AI agent at consumer scale
• Customer conversations are the main workload
• Outcome-based pricing for resolutions fits your budget
• Back-office investigations aren't in scope

Choose Runtime if

• The hard part is the investigation behind the ticket, across ledger, processor, and bank data
• You want support, payment ops, finance, risk, and compliance on one platform
• Data and models have to stay in your cloud
• You need approvals on money movement and an audit trail your sponsor bank will accept

Frequently asked questions

Is Sierra good for fintech companies?

Sierra is a leading platform for branded, customer-facing AI agents across chat and voice. Fintech teams also have back-office work behind each conversation, such as payment traces, recon breaks, and risk reviews. Runtime covers those teams on one platform in your cloud.

Can Sierra run in my own cloud?

Sierra is offered as a hosted platform with vendor-managed models. Runtime runs agent computers in your AWS, GCP, or Azure account, or fully self-hosted, and lets you bring any model, including open-weight models in your cloud.

What is the best Sierra alternative for payment teams?

If the main workload is customer conversations at consumer scale, Sierra is a strong choice. If you want support, payment ops, finance, risk, and compliance agents sharing one investigation and one record, Runtime is built for that.

How is Sierra priced compared to Runtime?

Sierra uses outcome-based pricing. Runtime has a free tier, Teams plans from $99 per seat per month, and custom Enterprise pricing for self-hosting.

Where does Runtime fit next to Sierra?

Behind the conversation. Sierra agents talk to customers. Runtime is the AI agent harness for payment and fintech teams, and its agents work the investigations those conversations create across support, payment ops, finance, risk, and compliance, in your cloud, with approvals before money moves.