/**
 * defineFact — sugar for context-style Injections (data, not behavior).
 *
 * Use for developer-supplied facts the LLM should see in addition to
 * user messages and tool results. Examples: user profile, env info,
 * computed conversation summary, cached config, current time. Distinct
 * from Skills (LLM-activated guidance) and Steering (always-on rules)
 * in INTENT — they share the engine.
 *
 * Produces an `Injection` with:
 *   - flavor: `'fact'`
 *   - trigger: configurable (default `'always'`)
 *   - inject: `systemPrompt` (default), or `messages` with a declared role
 *
 * @example
 *   const userProfile = defineFact({
 *     id: 'user-profile',
 *     data: `Name: ${user.name}, Plan: ${user.plan}, Joined: ${user.joinedAt}`,
 *   });
 *
 *   const turnTime = defineFact({
 *     id: 'turn-time',
 *     data: `Current time: ${new Date().toISOString()}`,
 *   });
 */
import type { WireRole } from '../../../adapters/types.js';
import type { Injection, InjectionContext } from '../types.js';
import type { CachePolicy } from '../../../cache/types.js';
interface DefineFactBase {
    readonly id: string;
    readonly description?: string;
    /** The fact (data string) to inject. */
    readonly data: string;
    /**
     * Trigger control. Defaults to always-on. For conditional facts
     * (e.g., "only show user profile after iteration 3"), pass a
     * predicate via `activeWhen`.
     */
    readonly activeWhen?: (ctx: InjectionContext) => boolean;
    /**
     * Cache policy for this fact injection. Defaults to `'always'` —
     * facts are typically static data the LLM should always have in mind.
     * Override with `'never'` for facts containing volatile content
     * (e.g., a `Current time:` fact); use `{ until }` for time-bounded
     * facts.
     */
    readonly cache?: CachePolicy;
}
/**
 * `slot` and `role` are ONE decision, so the type makes them one choice.
 *
 * `slot: 'messages'` requires a `role` and there is deliberately no default:
 * who appears to speak is a meaning the app owns. (Before 7.19.1 the option
 * existed with `role` defaulting to `'system'` — a default that reached the
 * model on OpenAI-family providers and vanished on Anthropic-family ones.
 * Now the role is stated, and a provider that cannot carry it refuses at run
 * start by name.) `slot: 'system-prompt'` forbids `role`, because there is no
 * role in a system prompt to choose.
 */
export type DefineFactOptions = DefineFactBase & ({
    /** The default. The one placement every provider delivers. */
    readonly slot?: 'system-prompt';
    readonly role?: never;
} | {
    /**
     * Deliver the fact into the conversation itself — it enters
     * `scope.history` at the injection-engine boundary, so the window
     * strategies, the slots and the wire all see the same past.
     * Placed at the END of the window; if its role would collide with
     * the turn already there, delivery defers to the next boundary and
     * says so on `messagesDelivery.deferred`.
     */
    readonly slot: 'messages';
    /**
     * Who appears to say it. Required — no default. Refused at run start
     * when the attached provider does not carry it inside `messages`
     * (the Anthropic family drops `'system'` there; the OpenAI family
     * carries it). `'tool'` is refused outright: a tool message answers a
     * specific call, and an injection has no call to answer.
     */
    readonly role: WireRole;
});
export declare function defineFact(opts: DefineFactOptions): Injection;
export {};