Every product team we talked to in the last twelve months was building the same thing:
- A
messagestable to store conversations - A conversation memory model
- A loop that parses tool calls, dispatches them, and feeds the results back
- A prompt templating system
- Per-tenant API key auth
- A way to switch providers when one goes down
- Prepaid usage controls so model and workspace spend cannot run away
- Logging, audit, replay
None of that is anyone's product. All of it is on them.
Nimblesite is that stack, as a service.
What it is
You POST one JSON config:
{
"name": "Site Editor",
"system_prompt": "You edit websites for {tenant_name}.",
"model_config": {"provider": "anthropic", "model": "claude-sonnet-4-6"},
"tools_config": ["read_file", "write_file"]
}
You get back a config_id. From then on, your app calls:
curl -X POST /api/v1/chat/$CONFIG_ID \
-H "X-API-Key: $KEY" \
-d '{"message": "Hi"}'
Memory, the agent loop, tool dispatch, multi-tenancy, prompt templating, model routing — all already wired up. You send a message, you get an answer. The next call already remembers what happened.
What it isn't
- Not a framework. You don't import anything to start. It's a direct HTTP API with OpenAPI, Swagger UI, and ReDoc available today. SDKs for every major platform will be released.
- Not a tool runtime. We never execute your tools. The agent decides what to call; your app runs it. Your data, your APIs, your secrets stay in your trust boundary.
- Not a raw model wrapper. We run inference, track provider churn, and charge from a prepaid balance so spend stays bounded.
- Not a chatbot product. It's the backend you'd build if you were going to build a chatbot. Put a chat widget on top of it in an afternoon — or use it headless for agentic workflows.
Why this, why now
Three things collided:
- Almost every AI use case is agentic now. A one-shot completion is rare. Customers expect memory, tools, follow-ups, multi-turn flow. That means an agent loop — and nobody on your team signed up to write one.
- LLM APIs are still stateless. None of them store your conversation for you. The state problem is unsolved at the API layer, on purpose.
- The model landscape moves every week. A new frontier model, a new SDK, a new pricing tier, a new tool-call schema. Keeping up is a full-time job.
Nimblesite handles all three. Configure once, talk forever, and when the next model drops you change one line of JSON.
It also gives you a sane commercial boundary: prepaid, predictable, metered pricing. Empty balance stops the next billable call before vendor cost is incurred.
Try it
Nimblesite is a proprietary hosted API. Create your free account, grab an API key, and POST JSON — there is nothing to clone, install, or run.
Sign up free → Read the quickstart
- Quickstart — Get from zero to a working agent in under 5 minutes.
- Pricing — Prepaid, predictable metered usage. Roughly 2× the underlying AI and container cost, with monthly prepaid plans possible later.
Two HTTP calls and you have a working agent in your product. Production templates help you start from a real pattern instead of a blank config. That's the pitch.