Providers

provider.name is one row of the registry below. Every adapter package is a dependency of @chat-aide/sveltekit, installed with it; the one you name is loaded with a dynamic import() when the handler is created, and the others are never loaded. Should an adapter be missing anyway (a pruned install), handle.handler.ready and the first request reject with the exact pnpm add line.

provider: {
	name: 'anthropic',
	model: 'claude-haiku-4-5',  // required; there is no default model
	apiKey: '…',
	baseURL?: '…',             // proxies, EU endpoints, self-hosted servers
	headers?: { … },
	options?: { … }            // passed to the adapter's create* factory untouched
}

#Rules

• The library reads no environment variable. Every credential is a value you pass. Since an adapter given no apiKey would read its own variable (ANTHROPIC_API_KEY, …), every key-based row requires apiKey: handler creation throws provider.apiKey: is required… otherwise. Pass the key explicitly, or use fromEnv.
• No environment variable can redirect the key. When you give no baseURL, each key-based row passes its adapter's default endpoint explicitly, so ANTHROPIC_BASE_URL, OPENAI_BASE_URL and the like are never consulted. Bedrock's endpoint is built from region; Azure requires resourceName or baseURL; Vertex requires project and location; the presets pass their fixed URL.
• Only model objects reach the AI SDK, never a model-id string (in AI SDK 7 a bare string is a request to Vercel's AI Gateway). The library never reads or sets globalThis.AI_SDK_DEFAULT_PROVIDER.
• Vercel AI Gateway is not supported. A provider.name containing gateway is refused by the config schema, and so is a custom instance whose provider is a gateway model.
• The widget's disclosure line names the provider (its display name, e.g. "Anthropic", "Amazon Bedrock"; for openai-compatible the baseURL's host; for custom the instance's provider), learned from the warm-up.

#Official adapters

#Community and compatible

A preset's baseURL can be overridden like any other.

import { createAnthropic } from '@ai-sdk/anthropic';

// Any adapter the registry does not name, or a community one, is one factory call:
const model = createAnthropic({ apiKey, baseURL: 'https://api.anthropic.com/v1' })('claude-haiku-4-5');
aide({ provider: { name: 'custom', model: 'claude-haiku-4-5', instance: model } });

instance must be a model object with provider and modelId, never a string. For custom the library cannot see how you built the adapter, so pinning its endpoint and key is up to you. model is still required by the schema; the instance's modelId is what is reported.

#Prompt caching

caching: false removes the markers. See Configuration → the prompt for what keeps the prefix stable.

#fromEnv

fromEnv(env) builds a ProviderConfig from the object you hand it ($env/dynamic/private, process.env, platform.env). It reads only these variables and nothing from the process:

It throws, naming the variable, when a required one is missing, the name is not a row, or OPTIONS is not a JSON object. It never falls back to a provider's conventional variable (ANTHROPIC_API_KEY). custom cannot come from the environment. Values passed beside it win:

import { aide, fromEnv } from '@chat-aide/sveltekit/server';
import { env } from '$env/dynamic/private';

export const handle = aide({
	provider: { ...fromEnv(env), accessKeyId: env.AWS_ACCESS_KEY_ID, secretAccessKey: env.AWS_SECRET_ACCESS_KEY },
	origin: env.ORIGIN
});

(Bedrock's access keys and Vertex's credentials have no CHAT_AIDE_* variable; pass them like this, or rely on the platform's default credential chain.)