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Sierravs Callvu

Sierra builds AI agents for customer experience, with supervisor agents, deterministic and controlled access to systems of record, and actions such as payments, payment plans and mortgage preapproval. Callvu is the Completion and Compliance Layer: when a conversation becomes a regulated process, Callvu runs it end to end through the back office to the system of record with a deterministic orchestrator, enforcing every regulation and company policy on every step. Sierra can be the conversational front door and Callvu the governed process behind it.

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At a glance

Runtime compliance enforcement

SierraPartial.

CallvuYes.

Front-to-back-office handoff

SierraPartial.

CallvuYes, end to end: prefill from the core, classify the work, chase and verify documents, route decisions to the Decision Desk and write back to the system of record.

The fair version

What Sierra is built for.Sourced from their own pages.

Sierra builds AI agents for customer experience on Agent OS, with an SDK for developers, no-code tools, voice and messaging channels ^[1]^[4]. It describes supervisor agents that check what the main agent says and does ^[2], deterministic, controlled interactions with systems of record ^[3], PCI-compliant payments in which card data goes to the payment processor without the agent seeing it and prompts follow a predetermined, server-validated sequence ^[7], and AIUC-1 certification for its agents ^[8]. Horizon, launched in July 2026 ^[12], has agents work toward an outcome such as a mortgage or a claim over days or weeks, follow up with customers and third parties for missing forms and records, enforce consent and opt-out on every outbound touch, and stop where you require human sign-off ^[9]. Through Plaid, customers can connect a bank account inside the conversation, for example so an agent can review income for a loan application ^[13]. Agents take actions such as card and ACH payments, card activation and payment plans ^[7]; Rocket Mortgage uses Sierra to move homebuyers to preapproval and present personalized rates ^[10], and Chime is a customer ^[11]. Its customer list includes SoFi ^[5], and Sierra names Santander as an Agent OS customer ^[12]. Sierra's agent development team builds deployments with customers' consulting firms and systems integrators ^[6].

When to choose which

Two different jobs.Pick the one you need.

When to choose Sierra

Choose Sierra when the need is a branded conversational front door that answers, resolves and routes customer requests at scale ^[1], including payments under PCI requirements ^[7], and you want Sierra's team and your consulting partners to build it ^[6]. It fits consumer brands, banks, fintechs and lenders such as Santander, Rocket Mortgage and Chime ^[10]^[11]^[12].

When to choose Callvu

Choose Callvu when the conversation starts a regulated process that must reach the back office and the systems you already own. Callvu orchestrates the work, routes it by work type, skill and due date, applies rules and policies and manages every decision, and it runs the handoff in the same process with five moves: it prefills from what the core already knows, classifies each request the moment it lands, chases and verifies documents from customers and outside parties on a clock, routes decisions to the Decision Desk, and writes the result back by API.

Guardrails are not runtime enforcement. Sierra's agents take payments and set up payment plans ^[7], with deterministic, controlled access to systems ^[3] and supervisor agents checking them ^[2], and Horizon agents plan and carry out multi-week work such as a mortgage or a claim ^[9]. A supervisor is another AI checking the first one: it lowers the error rate but does not make the process deterministic. Even with guardrails, an AI that runs the process can write wrong data to the system of record, take a path that is not in the workflow, or act compliantly most of the time rather than every time. Callvu does not let AI run the process. A deterministic orchestrator decides every next step and enforces every control before the step runs; AI, yours or Callvu's, only starts a process or evaluates it. Every run is recorded in a Decision Trace and an Audit Trace.

Choose Callvu, too, when time and services cost matter. Sierra deployments are built with its agent development team and your consulting partners ^[6]. Callvu's license includes white-glove design, implementation, maintenance and optimization for as long as it runs, with no separate services project, and Callvu goes live in a few weeks.

Side by side

The verifiable facts.Nothing else.

Every cell about Sierra is sourced from its own public pages. Runtime enforcement and the handoff lead the table because they are where the two differ most.

Capability		Sierra
Primary role	Completion and Compliance Layer between every front door and the system of record	AI agents for customer experience across chat and voice, on Agent OS ^[1]
Runtime compliance enforcement	Yes. A deterministic orchestrator runs every step and decides the path; AI never runs the process. Every regulation and company policy is enforced on every step while the work runs, whether a person or an AI started it; a step that fails a control does not run. A Decision Trace and an Audit Trace for every run	Partial. Deterministic, controlled access to systems of record, a predetermined, server-validated sequence for payments, supervisor agents that check and can intercept the main agent, and in Horizon, consent and opt-out enforced on every outbound touch; the AI agent still conducts the conversation, plans the work and chooses its actions ^[3]
Front-to-back-office handoff	Yes, end to end: prefill from the core, classify the work, chase and verify documents, route decisions to the Decision Desk and write back to the system of record. Back-office planning starts the moment the front end starts	Partial. Agents act in connected systems through APIs. Horizon agents work toward an outcome such as a mortgage, a claim or a prior authorization over days or weeks, follow up with customers and third parties for missing forms and records, and stop where you require human sign-off. Document verification, a decision workspace for reviewers and a deterministic write back are not documented ^[9]
AI guardrails vs deterministic execution	Deterministic execution, not guardrails: AI never runs the process. A deterministic orchestrator executes every step and enforces every control before it runs, so nothing unchecked reaches the system of record and no step outside the workflow can happen	AI agents take card and ACH payments, activate cards and set up payment plans, with supervisory layers checking the AI ^[7]
Payments and sensitive data	Sensitive input never goes into an AI chat; consent, signature and payment stay on a process-controlled screen handed over prefilled	PCI-compliant payments: card details are entered on the phone keypad or in a secure embedded form and go to the payment processor, so the agent never sees raw card data; payment prompts follow a predetermined, server-validated sequence ^[7]
Evidence	Every action assessed before it runs by six evaluator agents, whether a person or an AI started it, with an immutable Decision Trace and Audit Trace pushed in real time to GRC and BI tools	Certifications include AIUC-1 for AI agents ^[8]
Deployment and professional services	White-glove design, implementation, maintenance and optimization included in the license, for as long as it runs; no separate services project. Live in a few weeks: PSEG Long Island went live in 4 weeks, and Phoenix Insurance integrated all core systems in 4 weeks	Built by Sierra's agent development team together with your consulting firms and systems integrators ^[6]

Using both together

Keep what works.Add the layer that finishes it.

Sierra can stay the conversational front door. When a conversation turns into a regulated request, Sierra starts a Callvu process: the customer's input carries into the run, disclosures, consent and identity checks stay on a process-controlled screen, and Callvu runs the back-office work and the write back to the system of record. Callvu can also run the whole process on its own, from any door.

Proof

Live in production.At regulated enterprises.

Banca Transilvania

73% of inbound call traffic migrated to digital self-service
3M+ support calls moved to digital self-service
100+ workflows automated
Loan decisions 4 days faster

Callvu helped us migrate 73% of our inbound call traffic to digital self-service. They transformed our customer experience in ways we didn't think were possible. That's no easy task when you're dealing with everything that arises in consumer banking.Anca Radu, Digital Project Manager, Banca Transilvania

Bank Leumi

Leumi Paperless Branch, personal and business loans

Loan decisions 1 week+ faster (manual approval steps automated in Callvu workflows)
77% reduction in data errors
94% average successful customer completion rate
All loan application and servicing workflows digitized within six months
$3M+ savings on transcription and paper storage
91% reduction in digital experience development timelines

Phoenix Insurance

100+ processes live in under 3 months
All core systems integrated in 4 weeks
40% fewer agent-led calls
90%+ completion without human help
$3.5M+ annual service savings

FAQ

The questions buyers ask.Answered plainly.

Does Sierra enforce compliance at runtime?

Sierra documents deterministic, controlled access to systems of record, server-fixed prompts for payments and supervisor agents that check the main agent and can intercept it. Those constrain an AI agent that is conducting the conversation and choosing its actions. In Callvu, a deterministic orchestrator decides the path and runs every step, AI never runs the process, and every regulation and company policy is enforced on every step before it executes.

Are supervisor agents the same as runtime enforcement?

No. A supervisor agent is another AI checking the first one, which lowers the error rate but does not make the process deterministic. Even with supervisors, an AI that runs a step can write wrong data to the system of record, take a path that is not in the workflow, or act compliantly most of the time rather than every time. Callvu removes AI from execution: the orchestrator runs every step and enforces every control before it runs.

Can Sierra and Callvu work together?

Yes. Sierra can be the conversational front door, and Callvu runs the regulated process behind it: required disclosures, consent and identity checks on a process-controlled screen, documents chased and checked, decisions in the Decision Desk and the write back to the systems you already own.

What are alternatives to Sierra for a bank or credit union's regulated requests?

For a branded conversational agent, Sierra is a strong option. For regulated requests that must finish in the core, the loan system or with outside parties, Callvu runs the process end to end deterministically, behind any AI agent or with Callvu AI chat, live in a few weeks with implementation included in the license.

How fast can Callvu go live behind an AI agent?

Callvu builds the process for you and launches in a few weeks, with white-glove implementation included in the license. A proof of value runs on one of your own processes first.

Sources

Every claim,sourced.

Last verified: 2026-11-05. Facts about other vendors come from their public pages, filings and press, as of that date. Vendor names are trademarks of their owners. To report an error, contact Callvu.

See it on your process.

Bring one regulated process. We will show you the handoff and runtime enforcement on it.

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