Not Diamond vs Kong AI Gateway
Both are llm gateways tools. Here is how they actually differ on price, billing model and deployment.
Not Diamond
A model router that recommends rather than proxies - it tells your gateway which model to call and gets out of the way. That architecture means no request-path dependency, which nothing else in this category offers.
Kong AI Gateway
AI routing built into Kong's established API gateway. The right answer if Kong already fronts your APIs and governance is the priority - an expensive one if you are adopting Kong just for this.
| Not Diamond | Kong AI Gateway | |
|---|---|---|
| Category | LLM Gateways | LLM Gateways |
| Our rating | 4/5 | 3/5 |
| Starting price | Conflicting reports | Around $500/mo (Konnect) |
| Billing meter | No usage metering | No usage metering |
| Free plan | Yes | Yes |
| Free self-hosting | No or paid tier only | Yes, free |
| Best for | Teams already running a gateway who want smarter per-request model selection without putting another vendor in the request path, particularly for coding agents where model spend is high and uncontrolled. | Organisations already standardised on Kong for API management, where bringing LLM traffic under existing governance matters more than LLM-specific features. |
Our verdict on Not Diamond
Not Diamond is architecturally the most interesting thing in this category because it declines to be a gateway. Integrations are stack-agnostic through its API, and recommendations are executed in your own model gateway and harness - so it tells you which model to call and gets out of the way. Every other router in this category is a proxy, which means adopting it creates a request-path dependency and a new availability risk. Not Diamond has neither. It composes with LiteLLM, Vercel, Cloudflare or your own proxy rather than replacing any of them, which makes it unusually low-commitment to try. The product is a pre-trained Chat router, a Code router aimed at coding-agent cost currently in early access, and custom routers trained on your own data. That last one matters most, because the weakness of generic routing is that your workload is not the benchmark it was tuned on. The unsatisfying part is pricing, where sources directly contradict each other, and the fact that the most differentiated capability is still early access.
Full Not Diamond review →Our verdict on Kong AI Gateway
Kong AI Gateway is a straightforward proposition that depends almost entirely on one question - do you already run Kong? If you do, this is close to an obvious choice. LLM traffic comes under the same policy, authentication, rate limiting and governance as the rest of your APIs, managed by the same platform team through the same control plane, rather than existing as a parallel system nobody owns. For an organisation where API governance is already a formal function, that consolidation is worth more than any LLM-specific feature. If you do not already run Kong, the calculation inverts sharply. Konnect is reported at roughly $500 to $2,500 a month against Cloudflare AI Gateway's $5 or self-hosted LiteLLM's infrastructure cost, and the LLM-specific capabilities are thinner than dedicated AI gateways. You would be adopting a substantial API management platform to solve a problem that cheaper, more focused tools solve directly.
Full Kong AI Gateway review →Frequently Asked Questions
What is the main difference between Not Diamond and Kong AI Gateway?
Not Diamond: Teams already running a gateway who want smarter per-request model selection without putting another vendor in the request path, particularly for coding agents where model spend is high and uncontrolled. Kong AI Gateway: Organisations already standardised on Kong for API management, where bringing LLM traffic under existing governance matters more than LLM-specific features. Both sit in LLM Gateways, so the decision usually comes down to billing model and deployment rather than raw capability.
Which is cheaper, Not Diamond or Kong AI Gateway?
It depends entirely on your workload shape, because they meter differently - Not Diamond bills on no usage metering and Kong AI Gateway bills on no usage metering. Published starting prices are Conflicting reports and Around $500/mo (Konnect) respectively, but those numbers are not comparable until you apply them to the same traffic. Use our cost calculator to model both against your own request volume and span count.
Can I self-host Not Diamond or Kong AI Gateway?
Not Diamond: No or paid tier only. Kong AI Gateway: Yes, free. Free self-hosting means no licence fee, not no cost - you still own the infrastructure, upgrades and on-call.