Running a consulting practice as a solo operator requires a carefully chosen set of tools. Too few and you're doing manual work that should be automated. Too many and you're drowning in subscriptions and context-switching between platforms.
Here is the complete stack, tested across real consulting work, with every tool earning its place by the "No API, No Buy" criterion.
The Core Stack
Intelligence Layer
| Tool | Role | Cost | API |
|---|---|---|---|
| Google AI Studio | AI model access (Gemini 3.1 Pro/Flash) | Free tier / Pay-as-you-go | ✅ Full REST API |
| Antigravity / Codex | AI pair programming | Included with Google AI subscription | ✅ IDE integration |
| Ollama | Local model hosting | Free (open-source) | ✅ Local REST API |
Operations Layer
| Tool | Role | Cost | API |
|---|---|---|---|
| Notion | CRM, project management, content calendar | ~£8-10/month (Plus plan) | ✅ Full REST API |
| Obsidian | Private knowledge management, strategy | Free (core) | ✅ Local file access |
| n8n | Workflow automation | Free (self-hosted) + ~£10/month VPS | ✅ Full API + webhooks |
Content Layer
| Tool | Role | Cost | API |
|---|---|---|---|
| Canva | Visual design, brand assets | ~£10/month (Pro plan) | ✅ Content Publishing API |
| Veo 3.1 Lite | AI video generation | Pay-per-generation | ✅ Via Google AI API |
| Descript | Video/podcast editing | ~£20/month | ✅ Limited API |
Client-Facing Layer
| Tool | Role | Cost | API |
|---|---|---|---|
| Vercel | Website hosting | Free tier / £16/month Pro | ✅ Full deployment API |
| Stripe | Payments | 2.9% + 20p per transaction | ✅ Full REST API |
| SendGrid / Postmark | Transactional email | Free tier available | ✅ Full REST API |
Communication Layer
| Tool | Role | Cost | API |
|---|---|---|---|
| Google Workspace | Email, Calendar, Drive | ~£5-11/month | ✅ Full Google APIs |
| Slack / Discord | Client and community communication | Free tier available | ✅ Full API + webhooks |
Total Monthly Cost
For a fully operational solo consulting agency:
- Minimum viable stack: ~£30-50/month (Notion, Canva, Google Workspace, free tiers for everything else)
- Optimised stack: ~£80-120/month (adding paid AI usage, VPS for n8n, Vercel Pro)
Compare this to the traditional agency overhead—office space, employees, enterprise software licenses—and the economics of the one-person agency become obvious.
The Key Principle
Every tool in this stack has an API. Every tool can be connected to your automation layer (n8n). Every workflow can be orchestrated by your AI agent. The human stays on the balcony orchestrating the system through vibe coding; the system executes.
Tools that don't expose APIs create automation dead ends. They force you back to manual work. They don't earn a place in the stack.