Runtime vs Sierra
Runtime is one agent harness for every payment team, including support. Sierra builds conversational AI agents for customer experience.
TL;DR: Runtime is the stronger choice when you want agents across every team that touches a transaction, investigating payment issues end to end in your cloud. Sierra is a leading platform for branded, customer-facing AI agents.
| Feature |  Runtime |  Sierra |
|---|---|---|
| What it is | Agent harness for every payment team | Conversational AI agents for customer experience |
| Customer-facing conversations at scale | Supported channels for support teams | Core strength |
| Back-office investigations | Core use case | Not the focus |
| Teams covered | Support, payment ops, finance, risk, compliance | Customer experience |
| Runs in your cloud | Yes, or fully self-hosted | Hosted platform |
| Bring your own models | Any model, including local open models | Vendor-managed |
| Pricing | Priced against the headcount it replaces | Outcome-based |
Two different jobs
Runtime is the AI 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 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.
The right one depends on the work you're trying to hand off.
Why payment teams choose Runtime
Built for money movement
Payment work is mostly exceptions: a held payout, an ACH return with an odd code, a dispute where the evidence contradicts the claim. Runtime agents reason through those cases on their own computers, across your ledger, processor, bank files, and tickets, and stop for a person before anything moves money.
Your data stays yours
Agent computers run in your AWS, GCP, or Azure account, or you self-host the whole platform. Card numbers, SSNs, and secrets are masked before any prompt or log, and you can serve open-weight models locally for PCI and PII work.
One harness for every team
Support, payment ops, finance, risk, and compliance all build on the same harness, so one stuck payment is one investigation, not four. Every run is stored with its evidence, approvals, and cost, ready when an auditor or sponsor bank asks.
An engineer, not an account executive
A forward-deployed AI engineer who has built payment infrastructure maps your processes, builds the first agents with your team, and sets up guardrails.
When Sierra makes sense
- 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
When Runtime makes sense
- You run payments, banking, or lending operations and the queue keeps growing
- The work needs judgment on exceptions, not just a fixed sequence of steps
- Card data or PII has to stay in your environment
- You need approvals on money movement and an audit trail your sponsor bank will accept
- You want one platform for every team that touches a transaction
See Runtime on your busiest queue
Bring one SOP. A forward-deployed AI engineer builds the first agent with your team, inside your cloud.