A schematic diagram of the Fin AI Engine
Fin's CX Model Suite: Purpose-built for customer service

Meet Fin Apex 2.0 The best-performing model for customer service

THE BEST-PERFORMING MODEL FOR CX

Most models are built to be good at everything. Fin Apex is built to be exceptional at one thing: customer service.

Built by our AI team and trained on millions of support interactions, Fin Apex is optimized for customer service: providing accurate answers, following your policies reliably, and knowing when not to answer.

Apex 2.0 is our most capable answer generation model to date. Apex 1.0 already outperformed frontier models on resolution rate and speed. Apex 2.0 builds on that, with 8.6% more confirmed resolutions and 16.5% fewer hallucinations than Apex 1.0.

Fin model suite

Introducing the
Fin model suite

  • [ 1 ]

    Fin Apex 2.0 [ new ]

    Fin Apex illustration

    Apex 2.0 is the generative core of Fin. It takes the most relevant content retrieved and ranked by the Fin model suite, applies your configured policies, and produces a direct answer or decides the question needs a human. It builds on what we learned from Apex 1.0 in production, combining a stronger base model with new post-training data. The result is 8.6% more confirmed resolutions and higher answer accuracy.

    Specification
    • 1.1Grounded in your knowledge base, not general data
    • 1.2Answers directly, escalates honestly when it can't
    • 1.3Asks for clarification instead of guessing
    • 1.4Built on learnings from Apex 1.0 in production
    • 1.58.6% more confirmed resolutions vs. Apex 1.0
    • 1.616.5% fewer hallucinations vs. Apex 1.0
  • [ 2 ]

    Fin Apex Flash 2.0 [ new ]

    Apex Flash 2.0 is the next generation of Apex Flash, our lightweight version of Apex for latency-sensitive channels like Voice. It answers 24% faster and has 46% fewer hallucinations than the previous version.

    Specification
    • 2.1Built for latency-sensitive customer interactions
    • 2.2Grounded in your knowledge base, not general data
    • 2.324% faster answers vs. Apex Flash 1.0
    • 2.4Shorter answers that suit spoken conversation
  • [ 3 ]

    Fin Apex for Procedures [ new ]

    Apex for Procedures is the model behind Fin Procedures. It reasons through complex, multi-step queries, follows your business rules at each step, and decides what Fin should do next. It outperforms Sonnet 5, the best-performing frontier model we tested for this work.

    Specification
    • 3.1Reasons through complex, multi-step queries
    • 3.2Follows your rules and guidance at each step
    • 3.315% more confirmed resolutions vs. Sonnet 5
    • 3.437% fewer hallucinations vs. Sonnet 5
  • [ 4 ]

    Fin Retrieval

    The Fin Retrieval model scans all available knowledge sources and pulls out a small set of useful information.

    Specification
    • 4.1Understand intent behind the question
    • 4.2Search across all available content sources
    • 4.3Match on semantics, not just keywords
    • 4.4Select top N most likely candidates
  • [ 5 ]

    Fin Reranker

    The Fin Reranker model takes the retrieved content and scores each piece for relevance, accuracy, and usefulness in context. It then selects the final piece(s) for the LLM to use.

    Specification
    • 5.1Score relevance with respect to query
    • 5.2Evaluate context match and resolution fit
    • 5.3Downrank outdated or low-confidence sources
    • 5.4Output: final selected content for generation
  • [ 6 ]

    Fin Issue Summarizer

    The Fin Issue Summarizer model detects and extracts the user's issue from conversation history. Built on a fine-tuned 14B model, it transforms unstructured chat exchanges into clear, actionable issue summaries for downstream retrieval.

    Specification
    • 6.1Detect whether conversation contains an addressable issue
    • 6.2Extract summarized issue from multi-turn exchanges
    • 6.3Handle edge cases: greetings, feedback, and noise
    • 6.412.5% cost reduction vs frontier LLMs
  • [ 7 ]

    Fin Feedback Parser

    The Fin Feedback Parser model uses a multi-task ModernBERT architecture to interpret user responses. It classifies feedback sentiment, detects follow-up questions, and identifies conversation endings with state-of-the-art accuracy.

    Specification
    • 7.1Classify feedback type: positive, negative, or none
    • 7.2Detect follow-up questions in user messages
    • 7.3Identify when conversations have ended
    • 7.4Match LLM accuracy at a fraction of the cost
  • [ 8 ]

    Fin Language Detector

    The Fin Language Detector model uses XLM RoBERTa to accurately identify the user's language across 45 supported languages. It handles real-world challenges like typos, short messages, and script mismatches.

    Specification
    • 8.1Support 45 languages with high accuracy
    • 8.2Handle spelling mistakes and short context
    • 8.3Process script mismatches (e.g., Romanized Hindi)
    • 8.4Enable intelligent language fallback logic
  • [ 9 ]

    Fin Escalation Router

    The Fin Escalation Router model uses a multi-task ModernBERT architecture to decide when conversations should be handed off to human agents. It provides reasoning and cites matching business guidelines with over 98% accuracy.

    Specification
    • 9.1Decide: escalate, offer to escalate, or continue
    • 9.2Cite matching business escalation guidelines
    • 9.3Provide reasoning for escalation decisions
    • 9.40.5s faster than LLM-based routing
AI Team

Built by a world-class
team of AI experts

02Building models of this quality is only possible thanks to our 50-person, world-class AI team, led by Fergal Reid, and our decade-long experience building customer service software.

AI Group Leadership
Avatar of Fergal Reid
Fergal ReidChief AI Officer
Avatar of Brian McDonnell
Brian McDonnellSenior Director, Engineering
Avatar of Mario Kostelac
Mario KostelacPrincipal Machine Learning Engineer
Avatar of Alexey Tarasov
Alexey TarasovDirector, ML Engineering
Avatar of Fedor Parfenov
Fedor ParfenovPrincipal Machine Learning Scientist
Avatar of Pedro Tabacof
Pedro TabacofPrincipal Machine Learning Scientist
Avatar of Molly Mahar
Molly MaharPrincipal AI Product Designer
Avatar of Pratik Bothra
Pratik BothraPrincipal Machine Learning Engineer
Avatar of Rati Zvirawa
Rati ZvirawaSenior Director, AI Product Management
Avatar of Rob Clancy
Rob ClancyPrincipal Machine Learning Engineer
Our Guarantee

Performance backed by our $1 million guarantee

04Fin is the highest-performing Agent for customer service. We know others make the same claim, which is why we back ours with the Fin Million Dollar Guarantee.

Learn more
Security

Customer-first approach to data privacy and security

Schematics of the Fin AI Engine

05We have invested heavily in data privacy and security. These models are trained on deidentified data from past Fin interactions.

The following existing customers are automatically excluded from our training process:

  • Customers that have a BAA in place with us
  • Customer using an EU/AU regionally hosted workspace
  • Any customer that was previously granted an opt-out
FAQs

FAQs

What is Fin Apex 2.0?

Fin Apex 2.0 is our most capable model for customer service yet.

Apex 2.0 is our most capable answer generation model to date. Apex 1.0 already outperformed frontier models on resolution rate and speed. Apex 2.0 builds on that, with 8.6% more confirmed resolutions and 16.5% fewer hallucinations than Apex 1.0.

Apex Flash 2.0 is a lightweight version of Apex for latency-sensitive channels like the phone. It answers 24% faster and has 46% fewer hallucinations than the previous version.

Apex for Procedures is a new model trained to reason through complex, multi-step queries. It outperforms Sonnet 5, the best-performing frontier model we tested for this work, on all the metrics that matter most for complex queries, including 15% more confirmed resolutions and 37% fewer major hallucinations.

What is the Fin CX Model Suite?

The Fin CX Model Suite is a system of nine purpose-built AI models, each handling a discrete stage of resolving a customer support query: detecting language, summarizing the issue, retrieving knowledge, reranking results, generating the final answer, reasoning through multi-step procedures, parsing feedback, and routing escalations. Unlike general-purpose LLMs, every model in the suite is trained specifically for customer service rather than broad capability.

How does Fin decide when to answer versus escalate to a human?

The Fin Escalation Router model uses a multi-task ModernBERT architecture to choose whether to continue, offer escalation, or escalate the conversation. It cites matching business guidelines, provides reasoning for each decision, and is 0.5 seconds faster than LLM-based routing, with over 98% accuracy.

Is my customer data used to train Fin's models?

Fin's models are trained on de-identified data from past Fin interactions. Customers with a BAA in place, those using an EU or AU regionally hosted workspace, or any customer previously granted an opt-out are automatically excluded from the training process.

Who built the Fin CX Model Suite?

The suite was built by a 50-person AI team at Fin, led by Chief AI Officer Fergal Reid, combining over a decade of customer service software experience with specialized ML expertise. The team trains purpose-built models at each stage of the pipeline, including fine-tuned smaller models like the 14B Issue Summarizer and transformer architectures like ModernBERT for feedback parsing and escalation routing.

Get purpose built models for industry-leading performance