Almost every company ends up needing the same unglamorous plumbing: get data out of the databases and apps where it's created, and into the warehouse (or back out to other apps) where people can actually use it. Airbyte and Fivetran are the names most people know for this, but the space has split into much more specific sub-jobs — copying every database change the instant it happens, syncing data both ways with tools like Salesforce, checking whether a dashboard's numbers are actually correct, or generating realistic fake data so developers don't touch real customer records. Here are 8 real tools covering those specific jobs, all of which explicitly name Airbyte or Fivetran as one of their own alternatives.
The short version
For real-time database replication (change-data-capture), Artie is the specialist — and if you want the free, code-first alternative to a managed CDC platform, see our separate dlt vs Estuary comparison. For syncing data both ways between your warehouse and everyday business tools, Polytomic combines ETL and reverse ETL in one platform. If you want pipelines plus an AI layer that lets non-engineers query in plain English, Kleene.ai fits. For orchestrating pipelines and dbt workflows in Python, Tower is built for that. If you need realistic fake data instead of exposing real customer records to developers, Tonic.ai specializes in exactly that. For querying across your live databases without building an ETL pipeline first, Spice AI federates SQL in real time. If bad data reaching a dashboard is the actual fear, Velum Labs catches it before it ships. And if you want your dashboards themselves versioned like code, DAC is a free, open-source way to do that.
1. Artie — best for real-time change-data-capture
Artie is a fully-managed CDC platform that streams database changes into your warehouse in real time, without you having to build and operate Kafka or Debezium pipelines yourself. It offers sub-minute latency with exactly-once delivery guarantees and automatic schema evolution.
Price: Growth plan starts at $500/month, usage-based with volume discounts at scale; initial snapshots/backfills are free; Enterprise offers BYOC at custom pricing; 14-day free trial, no card required.
Good for: data platform teams that need real-time database-to-warehouse replication without operating CDC infrastructure themselves.
Watch out for: $500/month is pricier than self-hosting Airbyte or Debezium, it's a newer vendor (2023) than established players like Fivetran, and it's focused specifically on CDC, not general-purpose ETL from arbitrary API sources.
2. Kleene.ai — best for pipelines plus plain-English querying
Kleene.ai pulls data from 200+ sources into a warehouse and adds an AI assistant on top that lets you query it in plain English, bundling pipeline, modeling and AI query layer into a single product rather than three separate tools.
Price: Flat-fee subscription, pricing available on request — no public price list.
Good for: SMBs and lean data teams (finance, marketing, ops) who need pipelines without a dedicated data engineer to run them.
Watch out for: no public pricing means a sales call before you can budget, there's no open-source or self-hosted option unlike Airbyte, and the flat-fee model may be worse value than usage-based tools at small data volumes.
3. Polytomic — best for two-way sync (ETL + reverse ETL)
Polytomic moves data both ways between a company's warehouse and the everyday tools teams actually work in — Salesforce, Google Sheets, Stripe and more — combining ETL and reverse ETL in one platform instead of making you run two separate specialist tools.
Price: Starting at $500/month; Standard and Enterprise tiers require a sales conversation; Enterprise adds on-premises deployment, SSO and a dedicated engineer; 14-day free trial available.
Good for: RevOps, marketing and support teams at high-growth companies needing two-way data sync, not just one direction.
Watch out for: $500/month minimum with no public self-serve tier, and teams only needing one direction (pure ETL or pure reverse ETL) may find a specialist cheaper.
4. Tower — best Python-native orchestration
Tower is a Python-native orchestration platform for running data pipelines, dbt workflows and AI agents, on either serverless or self-hosted infrastructure, with a built-in Apache Iceberg lakehouse and automated table maintenance.
Price: Pricing structure not publicly detailed; both a managed serverless service and self-hosted runners are available for on-premises deployments.
Good for: data teams building internal data platforms who want Python-native orchestration integrated with dltHub, Polars and Apache DataFusion.
Watch out for: pricing isn't transparent on the public site, and there's limited public information on free-tier limits versus paid.
5. Tonic.ai — best for synthetic test data
Tonic.ai generates realistic fake versions of your production data — same shape and statistics, no real customer information — so developers can test against data that looks real without ever touching actual user records.
Price: Tonic Fabricate: Free (limited monthly credits), Plus $29/month plus overage, Enterprise on request. Tonic Structural and Textual are usage-based or Enterprise quote, with a self-hosted option.
Good for: engineering and data teams that need realistic test data without exposing real data, especially in regulated industries.
Watch out for: case-study numbers are self-reported and not independently audited, and pricing is fragmented across three products, so getting a full cost picture usually means contacting sales.
6. Spice AI — best for querying live data without an ETL step
Spice AI lets an AI agent or application query all your different databases and data sources with one SQL question — combining search, filtering and even AI model calls right inside the query — without the usual months-long project of building a pipeline first.
Price: Open source (Apache 2.0) free; Cloud is usage-based (tiers not publicly listed); Enterprise on request with SOC 2 Type II and a 99.9% SLA.
Good for: enterprise teams deploying AI agents that need real-time federated data, particularly in cybersecurity, financial services and SaaS.
Watch out for: query performance depends on the speed of the source systems it federates, cloud pricing isn't detailed publicly, and it's less suited than a data warehouse for massive centralized batch processing.
7. Velum Labs — best for catching bad data before it ships
Velum Labs watches every query hitting a company's warehouse, catches bad data before it reaches a dashboard, and automatically writes the rule that prevents the same issue from happening again, using live dependency-graph tracing to find the actual root cause.
Price: Not publicly disclosed; early access program targeting enterprise data teams.
Good for: data engineering teams at regulated enterprises (especially financial institutions) where a data error carries real compliance risk.
Watch out for: it's extremely early-stage (YC P26 batch), with a tiny team and no public pricing, and it's unproven at broad scale compared to established data-observability vendors like Monte Carlo.
8. DAC (Dashboard-as-Code) — best free way to version your dashboards
DAC lets you write a company dashboard the same way you write code — in text files you can save, review in a pull request, and hand to an AI assistant to edit — instead of clicking around a chart-builder UI. It's fully open source and self-hosted.
Price: Free and open source (AGPL-3.0), self-hosted; the only cost is your own infrastructure (database, hosting).
Good for: data engineers and teams who want dashboards versioned like code, and potentially generated or edited by AI agents.
Watch out for: there's no visual drag-and-drop editor, the AGPL-3.0 license is restrictive if you redistribute it as a hosted product, and the ecosystem is younger than Grafana or Metabase.
| Tool | Best for | Starting price | Category |
|---|---|---|---|
| Artie | Real-time change-data-capture | $500/mo | CDC |
| Kleene.ai | Pipelines + plain-English queries | On request | ELT + AI query |
| Polytomic | Two-way sync (ETL + reverse ETL) | $500/mo | ETL/Reverse ETL |
| Tower | Python-native orchestration | Not public | Orchestration |
| Tonic.ai | Synthetic test data | Free / $29/mo | Data privacy/testing |
| Spice AI | Live SQL federation, no ETL step | Free, open source | Data federation |
| Velum Labs | Catching bad data before it ships | Not public | Data quality/observability |
| DAC | Dashboards versioned as code | Free, open source | Dashboard-as-code |
None of these replace a warehouse or a BI tool — they sit around one, handling a specific job that plain Airbyte-style ETL doesn't cover well: true real-time CDC, two-way sync, synthetic data, live federation, or data quality checks. Several are young, early-stage companies (Velum Labs is barely out of Y Combinator) with pricing that isn't public, so budget a real sales conversation before committing to anything beyond the free tiers here. If you're just getting started and want to try something at zero cost first, Spice AI and DAC are both genuinely free and open source.