Method embedMessageContent

packages/memory/src/index.ts:1068–1124

(content: string)

  >({ max: DEFAULT_EMBEDDING_CACHE_MAX_SIZE });
  private firstEmbed: Promise<any> | undefined;
  protected async embedMessageContent(content: string) {
    // Key by the content hash (not the content itself) to keep keys small. Use the
    // 64-bit hash: h32 is only 32 bits, so distinct contents collide after ~tens of
    // thousands of entries, which would return another message's cached embeddings.
    const key = (await this.hasher).h64(content);
    const cached = this.embeddingCache.get(key);
    if (cached) {
      this.logger.debug('Embedding cache hit', { contentHash: key.toString(), chunks: cached.chunks.length });
      return cached;
    }
    const chunks = this.chunkText(content);

    if (typeof this.embedder === `undefined`) {
      throw new Error(`Tried to embed message content but this Memory instance doesn't have an attached embedder.`);
    }
    // for fastembed multiple initial calls to embed will fail if the model hasn't been downloaded yet.
    const isFastEmbed = this.embedder.provider === `fastembed`;
    if (isFastEmbed && this.firstEmbed instanceof Promise) {
      // so wait for the first one
      await this.firstEmbed;
    }

    let embedFn: typeof embedMany | typeof embedManyV5 | typeof embedManyV6;
    const specVersion = this.embedder.specificationVersion;

    switch (specVersion) {
      case 'v3':
        embedFn = embedManyV6;
        break;
      case 'v2':
        embedFn = embedManyV5;
        break;
      default:
        embedFn = embedMany;
        break;
    }

    const promise = embedFn({
      values: chunks,
      maxRetries: 3,
      // @ts-expect-error - embedder type mismatch
      model: this.embedder,
      ...(this.embedderOptions || {}),
    });

    if (isFastEmbed && !this.firstEmbed) this.firstEmbed = promise;
    const { embeddings, usage } = await promise;

    const result = {
      embeddings,
      chunks,
      usage,
      dimension: embeddings[0]?.length,
    };
    this.embeddingCache.set(key, result);
    return result;
  }