Decagon vs Sierra (2026): Enterprise AI Agents Compared

The short answer

• Choose Sierra for public sector, healthcare, payments heavy or global consumer brands, and for retention and revenue outcomes priced per result.
• Choose Decagon for support led teams that iterate fast on workflows, want Git versioned AOPs and prefer paying a known rate per conversation.

Both are quote only, enterprise first and sit on top of your helpdesk. Get both quotes.

Pricing

Item	Decagon	Sierra
Published rates	None	None
Default model	Per conversation (Decagon says most customers choose it)	Outcome based
Alternative model	Per resolution, higher rate, no charge for escalations	Outcomes can include saves, upsells, cross sells and purchases
Unresolved conversations	Billed on per conversation contracts	Usually not charged
Volume discounts	Yes, on both models	Contracted
Self serve	No	No

The two companies wrote opposing pricing essays on the same day in December 2024. Decagon argues per conversation billing avoids fights over what a resolution is, such as a frustrated customer who stops replying. Sierra argues outcome pricing aligns incentives because it is paid only when the agent delivers value.

In practice, this decides who carries the risk. On Decagon's default model, you carry it: weak resolution rates cost you. On Sierra's, the vendor carries more of it, but you must negotiate tight outcome definitions. A simple test: ask both for a quote on the same volume, then convert each to cost per resolved conversation at your expected resolution rate. Benchmark the result against Fin's published $0.99 per outcome on the AI Price Index.

Models and features

Feature	Decagon	Sierra
Building	Agent Operating Procedures in natural language, Git based versioning	Ghostwriter builds agents from SOPs, transcripts, images and audio; Agent Studio; Agent SDK
Voice	Own Chord speech model, 70+ languages, outbound calls, talk while working	Voice personas across 60+ locales, sentiment adaptive, inbound and outbound
Messaging	Chat, SMS	Web and app chat, WhatsApp, Apple Business Chat, SMS
Email	Yes	Yes
Other channels	Dedicated channel for consumers' personal AI agents	ChatGPT apps via MCP
Long running journeys	Outbound workflows in AOPs	Horizon multi day planning, Context Engine memory
Human assist	Decagon Assist (summaries, replies, actions)	Live Assist (replies and actions)
Testing and QA	Simulations, live A/B experiments, Watchtower QA, suggestions	Experiments, Monitors, Explorer research, observability
Models	Uses providers such as OpenAI and Anthropic with zero retention	Constellation of frontier, open weight and proprietary models with failover
Integrations	Salesforce, Zendesk, Intercom, Kustomer, Confluence, Contentful, Amazon Connect, RingCentral, MCP, SIP	Systems of record via Agent SDK, MCP

Head to head scenarios

Government agency or federal contractor

Winner: Sierra. It lists FedRAMP High. Decagon does not list FedRAMP on the pages we read.

Agent that takes card payments by phone

Winner: Sierra. PCI DSS Level 1 Service Provider certification with cardholder data isolated from its LLMs and storage, and thousands of card and ACH transactions a day by its account.

CX team that changes policies every week

Winner: Decagon. AOPs are written like SOPs, so the support team edits workflows directly, while engineers track versions in Git. Sierra's Ghostwriter also builds from SOPs, but Decagon's whole product is organized around team owned procedures.

Global brand with WhatsApp and Apple Messages

Winner: Sierra. WhatsApp and Apple Business Chat are listed channels, plus ChatGPT apps. Decagon lists chat, email, voice and SMS.

Voice in many languages

Winner: Decagon. 70+ languages on voice with automatic detection and switching, against Sierra's 58 languages across channels.

Budget certainty for a fixed annual plan

Winner: Decagon. A per conversation rate makes the bill a function of volume only, which is what Decagon says most customers choose.

Privacy

Decagon's security page lists SSO (Okta, Microsoft Entra), role based access, AES-256 at rest and TLS 1.2+ in transit, short lived scoped tokens for agent access, PII redaction via Google DLP, zero data retention with LLM providers, a supervisor model against hallucinations and tamper protected audit logs, with SOC 2, HIPAA, PCI, GDPR, CCPA, ISO and EU AI Act badges.

Sierra lists SOC 2, HIPAA, GDPR, PCI, FedRAMP High, CCPA, CSA STAR, ISO 27001 and ISO 42001, says data is used only as you instruct and never shared with other customers, and encrypts and masks PII automatically.

Both are strong. Sierra's list is longer and more specific, which matters most in procurement reviews.

Verdict

Sierra wins overall for enterprise buyers on published facts: broader compliance, more channels and outcome based pricing that shifts risk to the vendor. Decagon wins for CX led teams that want hands on control of workflows, more voice languages and predictable per conversation billing. If you do not need an enterprise contract, Intercom Fin at $0.99 per outcome is the published price benchmark for both. Read the full Decagon review and Sierra review.