The Stack Breakdown
This is what a well-run AI agency in 2026 uses internally, organized by function.
Project Delivery
Linear — project and task management. Clean, fast, developer-friendly. Notion — documentation, SOPs, client knowledge bases. Loom — async video for client updates, demos, and internal explainers.
Client Communication
Slack or Teams — shared channels with clients. Cal.com — meeting scheduling (open source, no Calendly subscription). Otter.ai — meeting transcription and notes.
AI Development Tools
OpenAI API + Claude API — LLM backbone for most client work. Voiceflow — chatbot builder (no-code/low-code, very capable). Botpress — open source chatbot platform for complex needs. Make.com — automation workflows. Pinecone or Chroma — vector databases for RAG applications.
Business Operations
Stripe — invoicing and subscriptions. QuickBooks or Wave — accounting. DocuSign or PandaDoc — contracts. 1Password — credential management (critical when handling client API keys).
Marketing
AgencyRadar — directory listing for inbound leads. Buffer — LinkedIn content scheduling. Google Search Console — SEO monitoring.
Total Cost
A lean agency stack costs roughly $300-500/month in software. Scale this with your team size. The goal is automation — every tool should save more time than it costs to manage.