Captain: RAG Frameworks

Founded 2025|San Francisco, CA|2-10 people|Unknown

What is Captain?

Captain is an API-first RAG platform that lets teams search large collections of unstructured documents — PDFs, S3 files, spreadsheets, scanned images — in plain English with just two API calls. Part of YC W2026, the company was founded by Lewis Polansky (CEO) and Edgar Babajanyan (CTO), who brings 4 years of experience scaling high-performance RAG pipelines.

The platform handles the entire ingestion pipeline automatically: OCR via Gemini 3 Pro, complex document parsing via Reducto, chunking, and embedding generation using Voyage AI contextualized embeddings. It employs hybrid retrieval combining dense embeddings with full-text search via reciprocal rank fusion, then re-ranks with Voyage rerank-2.5. Captain tops the Open-RAG-Benchmark with over 20% higher accuracy than standard RAG pipelines.

Captain integrates with 1,000+ data sources including S3, SharePoint, Google Drive, Confluence, Slack, and Notion. It includes role-based governance with granular metadata-based access control and is SOC 2 Type II certified. The platform provides managed vector storage, so teams don't need an external vector database.

Key features

Core capabilities this platform advertises.

Scalable knowledge search
Agent-optimized retrieval
Production-grade infrastructure
Accuracy-focused

Strengths and tradeoffs

What this tool does well, and the limitations to keep in mind.

Pros

Best-in-class accuracy — tops Open-RAG-Benchmark with 20%+ improvement over standard RAG
Turnkey setup with just two API calls to go from raw files to searchable knowledge base
Multimodal by default — handles text, images, tables, scanned documents, and complex PDFs
Broad data source integrations connecting to 1,000+ sources including S3, SharePoint, Confluence
SOC 2 Type II certified with enterprise-ready security from day one

Cons

Credit-based pricing varies significantly by document complexity, making budgeting unpredictable
Early-stage 2-person team may concern enterprises needing SLA guarantees
BYOC/on-prem deployment requires Enterprise plan with custom pricing

Plans & pricing

What's included in each plan, and how the tiers compare.

Starter

/month

Monthly

12,000 credits/year
Unlimited queries
1 month free trial
In-app & email support

Growth

,600/month

Monthly

1M credits/year
SOC 2 Type II certified
Priority support

Enterprise

Custom

Contact sales for a quote

Unlimited credits
Captain Datasets
BYOC/on-prem
Custom SLAs
Dedicated support

View official pricing page

Common use cases

Teams building AI agents that need accurate knowledge access

Agent knowledge retrieval
Enterprise search
Scalable RAG
Production retrieval systems

Using Captain with Respan

Captain powers the retrieval layer in RAG applications, while Respan monitors the LLM calls that consume retrieved results. Together they provide end-to-end observability from document retrieval through final LLM response.

Monitor RAG pipeline performance from Captain retrieval to LLM response via Respan
Track retrieval costs alongside LLM inference costs in Respan dashboards
Evaluate retrieval quality by correlating Captain search results with LLM output quality

Run Captain in production with Respan

10KFree traces/mo

1,000+Models

5 minSetup

Respan lets you trace LLM and agent calls across any model or framework, A/B test prompts on production traffic, and route requests across 1,000+ models through one gateway.

Try Respan free