Letta vs Stack AI
Which Form & Workflow AI tool is better in 2026?
Letta
Memory-first agents that learn and improve from experience with natural language.
Stack AI
No-code platform for enterprise AI agents and forms
Side-by-side
| Letta | Stack AI | |
|---|---|---|
| Tagline | Memory-first agents that learn and improve from experience with natural language. | No-code platform for enterprise AI agents and forms |
| Founded | — | 2023 |
| HQ | — | New York, US |
| Employees | 1-10 | 11-50 |
| Total funding | Undisclosed | $16.6M |
| Latest round | — | Series A · Oct 2024 |
| Valuation | — | — |
| Cheapest paid plan | — | From $99/mo |
| Free plan | ✓ Letta Code | ✓ |
| Free trial | ✓ | ✓ |
| Top tier price | — | Pricing not disclosed |
| Pricing summary | 1 published plans | Free · From $99/mo |
| Categories |
Capability matrix
Developer-facing capabilities and access signals for Letta and Stack AI.
| Capability | Letta | Stack AI |
|---|---|---|
| MCP support | ✗ | ✗ |
| Public API | ✗ | ✓ |
| Webhooks | ✗ | ✓ |
| OAuth 2.0 | ✗ | ✓ |
| SDK languages | 1 (Node.js) | 1 (rest) |
| Free plan | ✓ | ✓ |
| Free trial | ✓ | ✓ |
| Verified | ✗ | ✗ |
| Active deal | ✗ | ✗ |
🟢 Strengths of Letta
- Strong in Form & Workflow
🔵 Strengths of Stack AI
- Has raised more capital ($16.6M vs Undisclosed)
- Higher Neuron score (76 vs 21)
- Lower starting price ($99/mo)
- Newer company (2023)
Which should you choose?
Choose Stack AI if price matters most — it starts at Free · From $99/mo, which is friendlier for teams watching burn. Both Form & Workflow tools ship core features, so the cost delta often decides it for small teams and solo operators.
Choose Stack AI if you want the most established option — it has raised $16.6M, suggesting more runway for enterprise features, support, and long-term roadmap. For mission-critical workflows or larger teams, that stability often outweighs a lower monthly price.
Frequently asked questions
Letta vs Stack AI — which is better?
It depends on your priority. Letta is the leaner option; Stack AI is cheaper to start. See the side-by-side table above.
Is Letta cheaper than Stack AI?
No — Stack AI's cheapest paid plan is Free · From $99/mo, while Letta's is Free.
Do Letta and Stack AI offer free plans?
Letta: Yes, has a free plan. Stack AI: Yes, has a free plan.
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