/**
 * Chat Completion — pluggable chat/completion provider for the Graphile LLM plugin
 *
 * Provides a provider-based architecture for LLM chat completions.
 * Currently supports Ollama via @agentic-kit/ollama.
 *
 * Used by the RAG plugin to generate answers from retrieved context.
 *
 * Resolution order mirrors the embedder:
 *   1. The `llm_module` configuration (per-database)
 *   2. The preset's `defaultChatCompleter` option (fallback for dev/testing)
 *   3. Environment variables (CHAT_PROVIDER, CHAT_MODEL, CHAT_BASE_URL)
 */
import type { ChatConfig, ChatFunction, LlmModuleData } from './types';
/**
 * Build a chat completion function from a config object.
 *
 * @returns A ChatFunction, or null if the provider is not recognized
 */
export declare function buildChatCompleter(config: ChatConfig): ChatFunction | null;
/**
 * Build a chat completer from an `llm_module` row.
 *
 * @param data - The llm_module data from metaschema_modules_public.llm_module
 * @returns A ChatFunction, or null if the chat provider is not configured
 */
export declare function buildChatCompleterFromModule(data: LlmModuleData): ChatFunction | null;
/**
 * Resolve a chat completer from environment variables.
 * This is a fallback for development when no llm_module or defaultChatCompleter is configured.
 *
 * Environment variables (with defaults from env.ts):
 *   CHAT_PROVIDER  - Provider name (default: 'ollama')
 *   CHAT_MODEL     - Model identifier (default: 'llama3')
 *   CHAT_BASE_URL  - Provider base URL (default: 'http://localhost:11434')
 */
export declare function buildChatCompleterFromEnv(): ChatFunction | null;