/**
 * eve-owned shape for the model-facing tool result produced by
 * `toModelOutput`. Structurally compatible with the AI SDK's
 * `ToolResultOutput` so the harness can forward it without conversion.
 *
 * The `content` variant carries an ordered list of
 * {@link ToolModelOutputPart} entries, letting a tool hand the model
 * text alongside inline files (e.g. a screenshot as vision input).
 */
export type ToolModelOutput = {
    readonly type: "text";
    readonly value: string;
} | {
    readonly type: "json";
    readonly value: unknown;
} | {
    readonly type: "content";
    readonly value: readonly ToolModelOutputPart[];
};
/**
 * One part of a `content` {@link ToolModelOutput}. Mirrors the AI SDK's
 * `ToolResultOutput` content parts narrowed to the JSON-safe subset:
 * file data is the SDK's tagged `FileData` union restricted to
 * `{ type: "data" }` with a base64 string, so persisted tool results
 * survive the durable JSON boundary. Use the `toolOutputPart` builders
 * from `eve/tools` to construct parts without hand-writing the nesting.
 */
export type ToolModelOutputPart = {
    readonly type: "text";
    readonly text: string;
} | {
    readonly type: "file";
    /** Tagged file data; only JSON-safe base64 payloads are accepted. */
    readonly data: {
        readonly type: "data";
        readonly data: string;
    };
    /** IANA media type, e.g. `image/png`. */
    readonly mediaType: string;
    readonly filename?: string;
};
/**
 * Builders for the model-facing {@link ToolModelOutput} returned by
 * `toModelOutput`. Pure sugar over the union — each returns the
 * corresponding literal, and hand-written literals remain valid.
 *
 * ```ts
 * toModelOutput(output) {
 *   return toolOutput.content([
 *     toolOutputPart.text(`Screenshot of ${output.path}:`),
 *     toolOutputPart.file(output.screenshotBase64, { mediaType: "image/png" }),
 *   ]);
 * }
 * ```
 */
export declare const toolOutput: {
    /** Builds a text output: the model sees `value` as the tool result. */
    text(value: string): ToolModelOutput;
    /** Builds a JSON output; `value` must be JSON-serializable. */
    json(value: unknown): ToolModelOutput;
    /** Builds a content output from ordered {@link ToolModelOutputPart} entries. */
    content(value: readonly ToolModelOutputPart[]): ToolModelOutput;
};
/**
 * Builders for `content` {@link ToolModelOutput} parts. Pure sugar over
 * {@link ToolModelOutputPart} — each returns the corresponding part
 * literal, and hand-written literals remain valid.
 *
 * ```ts
 * toModelOutput(output) {
 *   return {
 *     type: "content",
 *     value: [
 *       toolOutputPart.text(`Screenshot of ${output.path}:`),
 *       toolOutputPart.file(output.screenshotBase64, { mediaType: "image/png" }),
 *     ],
 *   };
 * }
 * ```
 */
export declare const toolOutputPart: {
    /** Builds a text part. */
    text(text: string): ToolModelOutputPart;
    /**
     * Builds a file part from a base64 payload. Binary data must be
     * base64-encoded by the caller; raw bytes are rejected by the harness
     * because they do not survive the durable JSON boundary.
     */
    file(base64: string, options: {
        readonly mediaType: string;
        readonly filename?: string;
    }): ToolModelOutputPart;
};