# Best SaaS & B2B AI Agencies for Retainer Work

> 24 agencies. Top-ranked: Square Root Solutions, ontolux, OstraconAI.

Canonical page: https://www.aiagencies.eu/industries/saas/for/retainer
Generated: 2026-09-28 · Curated by Gabor Kiss · No paid placements — inclusion, score, and rank are never sold.

## Ranked roster
1. **Square Root Solutions** — Dublin, Ireland · €20-40/hr (directory-listed) · team 10-49 · founded 2018 · services: AI Development, Generative AI · 10 documented client engagements with source URLs · reviewed 2026-09-16 · https://www.aiagencies.eu/agency/square-root-solutions
2. **ontolux** — Berlin, Germany · rate not published · team 10-49 · services: AI Development, AI Consulting, Generative AI · 11 documented client engagements with source URLs · reviewed 2026-09-24 · https://www.aiagencies.eu/agency/ontolux
3. **OstraconAI** — Helsinki, Finland · €250-400/hr (agency-confirmed) · team 10-49 · founded 2024 · services: AI Consulting, AI Marketing, AI Automation · 11 documented client engagements with source URLs · reviewed 2026-09-23 · https://www.aiagencies.eu/agency/ostraconai
4. **Cloud District** — Madrid, Spain · €45-85/hr (directory-listed) · team 50-249 · founded 2010 · services: AI Development, AI Consulting · 11 documented client engagements with source URLs · reviewed 2026-09-20 · https://www.aiagencies.eu/agency/cloud-district
5. **Redkiwi** — Rotterdam, Netherlands · rate not published · team 10-49 · services: Generative AI, AI Marketing, AI SEO · 7 documented client engagements with source URLs · reviewed 2026-09-24 · https://www.aiagencies.eu/agency/redkiwi
6. **Found** — London, United Kingdom · €85-130/hr (directory-listed) · team 50-249 · founded 2005 · services: AI SEO, AI Marketing, AI Automation · 8 documented client engagements with source URLs · reviewed 2026-09-23 · https://www.aiagencies.eu/agency/found
7. **Data Analytics** — Rotterdam, Netherlands · rate not published · team 10-49 · services: AI Consulting · 10 documented client engagements with source URLs · reviewed 2026-09-24 · https://www.aiagencies.eu/agency/data-analytics
8. **HolistiCRM** — Budapest, Hungary · €20-40/hr (directory-listed) · team 2-9 · founded 2014 · services: AI Automation, AI Consulting, AI Development · 7 documented client engagements with source URLs · reviewed 2026-09-09 · https://www.aiagencies.eu/agency/holisticrm
9. **Hybrid Heroes** — Berlin, Germany · €85-130/hr (directory-listed) · team 10-49 · founded 2015 · services: AI Consulting, AI Development, Generative AI, AI Agents · 7 documented client engagements with source URLs · reviewed 2026-08-05 · https://www.aiagencies.eu/agency/hybrid-heroes
10. **QED Software** — Warsaw, Poland · €85-130/hr (directory-listed) · team 10-49 · founded 1999 · services: AI Consulting, AI Development, Generative AI · 7 documented client engagements with source URLs · reviewed 2026-09-23 · https://www.aiagencies.eu/agency/qed-software
11. **ClickSlice** — London, United Kingdom · rate not published · team 10-49 · founded 2016 · services: AI SEO · 6 documented client engagements with source URLs · reviewed 2026-09-24 · https://www.aiagencies.eu/agency/clickslice
12. **Atomic Actions** — Warsaw, Poland · €45-85/hr (directory-listed) · team 10-49 · founded 2024 · services: AI Automation, AI Consulting, AI Development · 5 documented client engagements with source URLs · reviewed 2026-09-23 · https://www.aiagencies.eu/agency/atomic-actions
13. **NOVOS** — London, United Kingdom · €130-170/hr (directory-listed) · team 10-49 · founded 2018 · services: AI SEO, AI Marketing · 5 documented client engagements with source URLs · reviewed 2026-09-23 · https://www.aiagencies.eu/agency/novos
14. **Spanish Point Technologies** — Dublin, Ireland · rate not published · team 50-249 · founded 2005 · services: AI Development, AI Consulting · 4 documented client engagements with source URLs · reviewed 2026-09-16 · https://www.aiagencies.eu/agency/spanish-point-technologies
15. **Contiamo** — Berlin, Germany · rate not published · team 10-49 · founded 2012 · services: AI Consulting, AI Development, Generative AI · 6 documented client engagements with source URLs · reviewed 2026-09-24 · https://www.aiagencies.eu/agency/contiamo
16. **Flobotics** — Warsaw, Poland · €85-130/hr (directory-listed) · team 10-49 · founded 2019 · services: AI Automation, AI Agents, AI Development · 3 documented client engagements with source URLs · reviewed 2026-09-07 · https://www.aiagencies.eu/agency/flobotics
17. **Boldare** — Amsterdam, Netherlands · €45-85/hr (directory-listed) · team 50-249 · founded 2004 · services: AI Development, Generative AI, AI Consulting · 5 documented client engagements with source URLs · reviewed 2026-09-24 · https://www.aiagencies.eu/agency/boldare
18. **Mobile Reality** — Warsaw, Poland · €39-57/hr (directory-listed) · team 10-49 · founded 2016 · services: AI Agents, AI Consulting, AI Development · 3 documented client engagements with source URLs · reviewed 2026-09-23 · https://www.aiagencies.eu/agency/mobile-reality
19. **Intunio** — Gothenburg, Sweden · €85-130/hr (directory-listed) · team 10-49 · founded 2015 · services: AI Development, AI Consulting · 3 documented client engagements with source URLs · reviewed 2026-09-09 · https://www.aiagencies.eu/agency/intunio
20. **Inbold** — Oslo, Norway · €85-130/hr (directory-listed) · team 50-249 · founded 2005 · services: AI Marketing, Generative AI, AI Consulting · 3 documented client engagements with source URLs · reviewed 2026-09-09 · https://www.aiagencies.eu/agency/inbold
21. **wukonig.com** — Graz, Austria · rate not published · founded 1999 · services: AI SEO, AI Consulting, AI Marketing · 3 documented client engagements with source URLs · reviewed 2026-09-09 · https://www.aiagencies.eu/agency/wukonig
22. **VisualLabs** — Budapest, Hungary · €45-85/hr (directory-listed) · team 10-49 · founded 2017 · services: AI Automation, AI Agents, AI Consulting · 3 documented client engagements with source URLs · reviewed 2026-09-23 · https://www.aiagencies.eu/agency/visuallabs
23. **Gemmo AI** — Dublin, Ireland · €45-85/hr (directory-listed) · team 10-49 · founded 2014 · services: AI Development, AI Consulting · 3 documented client engagements with source URLs · reviewed 2026-09-16 · https://www.aiagencies.eu/agency/gemmo-ai
24. **Fantasy Space** — Madrid, Spain · €20-40/hr (directory-listed) · team 10-49 · founded 2020 · services: AI Development, AI Agents, AI Automation, AI Consulting · 3 documented client engagements with source URLs · reviewed 2026-09-09 · https://www.aiagencies.eu/agency/fantasy-space

## Compared head-to-head
Curated comparison pages (published rates, team size, coverage, projected 12-week engagement cost, and the curator's verdict on both sides — pairings are never sold):
- Spanish Point Technologies vs Square Root Solutions: https://www.aiagencies.eu/compare/spanish-point-technologies-vs-square-root-solutions

## About this market
For software and B2B companies most retainers here fall on either side of the product boundary. Inside the product: Mobile Reality built the Nomis Index pricing and deposit-simulation MVP for Nomis Solutions in Node and React with post-update support, and CBRE Zone for CBRE Spain, neither with AI, while its open-source MDMA framework for LLM-generated forms is said to be deployed in fintech and proptech without a named client. Intunio has worked with Emerson's Rosemount Tank Radar on the user experience of its measurement software since 2021 and built Electrolux Shape from scratch in 2018, design-system retainers; model work goes to partners by its own account. Around the go-to-market: OstraconAI built Singa's inbound lead pipeline on n8n and Gemini, live in week three; Redkiwi launched Verder Liquids in 24 countries and 28 languages with quote requests up 168%; wukonig.com ran a prompting program for TCM International's sales team. Data Analytics runs managed BI, a 40-million-row environment at Deloitte, with no model in production. NOVOS's case studies are consumer e-commerce, and the curator calls B2B its weaker fit. Some retainers sit in back-office operations instead: Flobotics' bots move data between electronic health record systems for DocPlanner at more than 10,000 processes a month, 98% handled automatically.

Decide which boundary the retainer crosses. A product retainer has to work inside your release train, so ask who reviews pull requests and whether the agency's engineers or a partner's own the model; Mobile Reality's team page lists no data scientist. A go-to-market retainer runs on accounts and workflows, so ask who owns them after the engagement, the question the curator puts to OstraconAI directly.

## Questions buyers ask

### How many AI agencies work with retainer on saas & b2b?
24 agencies in our directory combine verified retainer client evidence with documented SaaS & B2B work. The current top-ranked are Square Root Solutions, ontolux, OstraconAI — ordered by depth of documented client evidence, then our editorial scoring (portfolio quality, credibility, completeness); placement is never paid.

### How much does an AI agency cost for saas & b2b?
Published rates across this page's agencies run €20–400 per hour (median ~€65). Project totals depend on scope — the rate index at /rates breaks the computed bands down by region, country and team size.

### How is the retainer model verified?
Every agency here documents retainer work on its own site or in a published case study, describing the engagement structure rather than a service-list claim. We never infer the model from portfolio tone, so this list only contains agencies that operate retainer engagements deliberately.

### Can these agencies embed consultants with our team?
2 of the agencies on this page document an embedded / team-extension working model. See the team-extension page for the full verified list, or check the engagement chips on individual profiles.

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Source: AIAgencies.eu — the curated register of European AI agencies. Rate provenance: "agency-confirmed" = disclosed via submission or claimed profile; "directory-listed" = Clutch or two agreeing B2B directories (lone unverified sources are never written). Full method: https://www.aiagencies.eu/methodology · Rate index: https://www.aiagencies.eu/rates