openLibrary.ts

import {
  BaseToolOptions,
  BaseToolRunOptions,
  Tool,
  ToolInput,
  JSONToolOutput,
  ToolError,
  ToolEmitter,
} from "bee-agent-framework/tools/base";
import { z } from "zod";
import { createURLParams } from "bee-agent-framework/internals/fetcher";
import { GetRunContext } from "bee-agent-framework/context";
import { Callback, Emitter } from "bee-agent-framework/emitter/emitter";

type ToolOptions = BaseToolOptions & { maxResults?: number };
type ToolRunOptions = BaseToolRunOptions;

export interface OpenLibraryResponse {
  numFound: number;
  start: number;
  numFoundExact: boolean;
  q: string;
  offset: number;
  docs: Record<string, any>[];
}

export class OpenLibraryToolOutput extends JSONToolOutput<OpenLibraryResponse> {
  isEmpty(): boolean {
    return !this.result || this.result.numFound === 0 || this.result.docs.length === 0;
  }
}

export class OpenLibraryTool extends Tool<OpenLibraryToolOutput, ToolOptions, ToolRunOptions> {
  name = "OpenLibrary";
  description =
    "Provides access to a library of books with information about book titles, authors, contributors, publication dates, publisher and isbn.";

  inputSchema() {
    return z
      .object({
        title: z.string(),
        author: z.string(),
        isbn: z.string(),
        subject: z.string(),
        place: z.string(),
        person: z.string(),
        publisher: z.string(),
      })
      .partial();
  }

  public readonly emitter: ToolEmitter<
    ToolInput<this>,
    OpenLibraryToolOutput,
    {
      beforeFetch: Callback<{ request: { url: string; options: RequestInit } }>;
      afterFetch: Callback<{ data: OpenLibraryResponse }>;
    }
  > = Emitter.root.child({
    namespace: ["tool", "search", "openLibrary"],
    creator: this,
  });

  static {
    this.register();
  }

  protected async _run(
    input: ToolInput<this>,
    _options: Partial<ToolRunOptions>,
    run: GetRunContext<this>,
  ) {
    const request = {
      url: `https://openlibrary.org?${createURLParams({
        searchon: input,
      })}`,
      options: { signal: run.signal } as RequestInit,
    };

    await run.emitter.emit("beforeFetch", { request });
    const response = await fetch(request.url, request.options);

    if (!response.ok) {
      throw new ToolError(
        "Request to Open Library API has failed!",
        [new Error(await response.text())],
        {
          context: { input },
        },
      );
    }

    const json: OpenLibraryResponse = await response.json();
    if (this.options.maxResults) {
      json.docs.length = this.options.maxResults;
    }

    await run.emitter.emit("afterFetch", { data: json });
    return new OpenLibraryToolOutput(json);
  }
}