// faq
Frequently asked questions
What Functional AI is, how it works, and where it's at. Still have a question? Get in touch.
What is Functional AI?
Functional AI is a runtime for AI features. You build your prompt, agent, or multi-agent workflow as a function; we host it, evaluate it, keep it running, and let you ship new versions anytime. You just call it from your code.
What can I build with it?
Anything from a single prompt to a multi-step agent or a multi-agent workflow. However you build it, it becomes one typed function you call over an API.
Which models can I use?
Any model. Use one we host with usage billed at cost, or plug in your own provider’s endpoint and credentials. You’re never locked into a single model or provider.
What happens if a model fails or slows down?
Functional AI monitors every call and automatically falls back to a backup model the moment your primary fails. Your function keeps answering and your users never notice.
How does evaluation work?
Define a dataset and a quality threshold, and every version is scored before it ships. Regressions fail the check, so you know a change is better — and cheaper — before a user ever sees it.
How do I call my function?
Like any API. Promote a version and you get a stable, authenticated HTTP endpoint that returns typed output plus metadata — version, latency, cost, confidence, a status (success, partial, failed, or escalated), and a trace ID you can use to pull the full run. There are SDKs for TypeScript, Python, and Go.
How does eval work for open-ended output?
Structured outputs — categories, enums, extracted fields — are graded by exact and field-level match, so the score is deterministic. Open-ended output (free text, agent transcripts) is scored with model-graded checks, which we treat as a signal, not ground truth: LLM judges carry known biases, so we track scores per version and expect you to keep a human review cadence as the calibration layer. Automated scoring scales coverage; it doesn’t replace judgment.
How do you handle prompt injection and tool security?
Defense in depth, and we’re honest that injection isn’t a solved problem. Tool output — web pages, documents, API responses — is treated as untrusted data, never as instructions. Tools run with least privilege, read-only access is separated from write access, and destructive actions (send, delete, pay, publish) can require human confirmation or run in a sandbox first. Secrets never appear in prompts, logs, or traces. The goal is to make injection harder and contain the blast radius if it lands.
What happens when an agent can’t finish a task safely?
It degrades instead of guessing. If a step, token, or time budget is hit, or a required tool is unavailable, the function returns the best partial answer with an explicit partial or escalated status — never a confident wrong answer. From there you can route to a fallback or a human.
Can I change a function without redeploying my app?
Yes. New versions go live behind the same function call, so you ship improvements without redeploying your app — and roll back instantly if you need to.
How much does it cost?
See the pricing page for launch plans. Usage on models we host is billed at cost; usage on your own provider is billed by that provider.
Do you support prompts, agents, and multi-agent workflows equally?
Yes. Functional AI treats all three as functions. Start with a prompt and grow into an agent or a multi-agent workflow without changing how you call it.
Is it available yet?
Not yet — Functional AI is in private beta. Join the waitlist and we'll send an invite when it opens. Shipping AI in production today? Apply to be a design partner.