Callab AI

AI voice agents for on-prem telephony stack.

4.2Score#135 of 999 agents#13 of 35 in Customer support agent

Why it ranks #135

Callab AI, an AI customer support agent from YC Sp26, ranks #135 of 999 AI agents and #13 of 35 in Customer support agent, with a score of 4.2 of 10. Data as of 3 Oct 2026.

The score adds four parts, each 0 to 10, by weight. Every point comes from public evidence. How scoring works ·

Proof 3 × 30% 0.9
Scale 3 × 30% 0.9
Momentum 6 × 25% 1.5
Autonomy 6 × 15% 0.9
= 4.2

Proof
Do customers use it? 30% of the score
3
Claims named customers.
- +3
  Named customers
  “We serve clients across three continents, including brands like Dunkin Donuts.”
  YC page
Not found: revenue or growth (+4), a customer result (+2), a customer count (+2), work done at scale (+2)
Scale
Is there a real company behind it? 30% of the score
3
7 people.
- +3
  7 people on its YC page5 to 9 people
Not found: funding round in its news (+3)
Momentum
Is it shipping and growing now? 25% of the score
6
Shows a recent launch, hiring and a new batch.
- +3
  Launched in the last 6 monthsCallab AI - AI voice agents for legacy phone systems.Launch YC post · 22 May 2026
- +2
  Hiring: 2 open rolesGrowth Marketer, Head of SDRYC page
- +1
  New: YC Spring 2026
Not found: new traction claim in the last 6 months (+2), funding news in the last year (+2)
Autonomy
How much of the job does it do on its own? 15% of the score
6
Supervised agent: takes actions in other systems; a person approves key steps.
- +6
  Level 2 of 4: Supervised agentTakes actions in other systems; a person approves key steps.
What the model read
- Acts in other systems: 85% likely
- Finishes whole tasks: 38% likely
- Calls itself an agent: 95% likely
Level 2: Takes actions in other systems; a person approves key steps.

About Callab AI

58% of the $400B call center industry runs on on-prem phone systems, and until now bringing AI voice automation to them meant ripping out their entire infrastructure first. That's the largest unserved segment in the market. Callab AI connects directly to legacy PBX systems like Avaya, Cisco UCM, and Mitel, and automates up to 70% of call volume with zero migration needed.

We plug into these environments without requiring a rip-and-replace. We serve clients across three continents, including brands like Dunkin Donuts.