Type Meanings

The following terms are fundamental to how Ahnlich requests are structured and processed in the Node.js SDK.

StoreKey

A one-dimensional float32 vector that uniquely identifies an item in a DB store.

• Functions like a primary key in a database
• Vector dimension must match the store's configured dimension
• Used in DB operations (Set, GetKey, DelKey, GetSimN)

import { StoreKey } from "ahnlich-client-node/grpc/keyval_pb";

const key = new StoreKey({ key: [1.0, 2.0, 3.0, 4.0] });

StoreValue

A map of string keys to MetadataValue containing the payload associated with an entry.

• Stores metadata like titles, descriptions, categories
• Can contain both text and binary data

import { StoreValue } from "ahnlich-client-node/grpc/keyval_pb";
import { MetadataValue } from "ahnlich-client-node/grpc/metadata_pb";

const value = new StoreValue({
  value: {
    label: new MetadataValue({ value: { case: "rawString", value: "Product A" } }),
    category: new MetadataValue({ value: { case: "rawString", value: "Electronics" } }),
  },
});

StoreInput

A raw string or binary blob accepted by the AI proxy for automatic embedding generation.

• Used in AI operations instead of StoreKey
• The AI server converts inputs to embeddings automatically

import { StoreInput } from "ahnlich-client-node/grpc/keyval_pb";

// Text input
const textInput = new StoreInput({
  value: { case: "rawString", value: "Hello world" },
});

// Binary input (e.g., image)
const imageInput = new StoreInput({
  value: { case: "image", value: new Uint8Array([...]) },
});

Predicates

Operations that define how filtering is performed on metadata.

Predicate	Description	Example
Equals	Match exact value	label = "A"
NotEquals	Exclude exact value	status != "archived"
In	Match if value in set	category IN ["A", "B"]
NotIn	Match if value not in set	status NOT IN ["deleted"]
Contains	String contains substring	name CONTAINS "shoe"
NotContains	String doesn't contain	name NOT CONTAINS "test"

import { Predicate, Equals } from "ahnlich-client-node/grpc/predicate_pb";
import { MetadataValue } from "ahnlich-client-node/grpc/metadata_pb";

const predicate = new Predicate({
  kind: {
    case: "equals",
    value: new Equals({
      key: "category",
      value: new MetadataValue({ value: { case: "rawString", value: "shoes" } }),
    }),
  },
});

PredicateCondition

Conditions that wrap predicates and allow combining them logically.

• Can represent a single predicate
• Can combine predicates with AND or OR

Single Predicate

import { PredicateCondition, Predicate, Equals } from "ahnlich-client-node/grpc/predicate_pb";
import { MetadataValue } from "ahnlich-client-node/grpc/metadata_pb";

const condition = new PredicateCondition({
  kind: {
    case: "value",
    value: new Predicate({
      kind: {
        case: "equals",
        value: new Equals({
          key: "brand",
          value: new MetadataValue({ value: { case: "rawString", value: "Nike" } }),
        }),
      },
    }),
  },
});

AND Condition

import { PredicateCondition, Predicate, Equals, AndCondition } from "ahnlich-client-node/grpc/predicate_pb";
import { MetadataValue } from "ahnlich-client-node/grpc/metadata_pb";

const condition = new PredicateCondition({
  kind: {
    case: "and",
    value: new AndCondition({
      left: new PredicateCondition({
        kind: {
          case: "value",
          value: new Predicate({
            kind: {
              case: "equals",
              value: new Equals({
                key: "brand",
                value: new MetadataValue({ value: { case: "rawString", value: "Nike" } }),
              }),
            },
          }),
        },
      }),
      right: new PredicateCondition({
        kind: {
          case: "value",
          value: new Predicate({
            kind: {
              case: "equals",
              value: new Equals({
                key: "category",
                value: new MetadataValue({ value: { case: "rawString", value: "Running" } }),
              }),
            },
          }),
        },
      }),
    }),
  },
});

MetadataValue

The container used inside predicates and store values to hold data.

Type	Description
rawString	Text data
image	Binary image data

import { MetadataValue } from "ahnlich-client-node/grpc/metadata_pb";

// String value
const textValue = new MetadataValue({
  value: { case: "rawString", value: "Hello" },
});

// Binary value
const binaryValue = new MetadataValue({
  value: { case: "image", value: new Uint8Array([0x01, 0x02, 0x03]) },
});

AIModel

The set of supported AI models within Ahnlich AI.

Model	Type	Description
ALL_MINI_LM_L6_V2	Text	Sentence transformer (384 dimensions)
BGE_BASE_EN_V1_5	Text	BAAI text embeddings
BGE_LARGE_EN_V1_5	Text	BAAI large text embeddings
RESNET50	Image	Image classification
CLIP_VIT_B32	Multimodal	Text and image embeddings
BUFFALO_L	Face	Face detection/recognition
SFACE_YUNET	Face	Face detection with YuNet
CLAP	Audio	Audio embeddings

import { AIModel } from "ahnlich-client-node/grpc/ai/models_pb";

const model = AIModel.ALL_MINI_LM_L6_V2;

Algorithm

Similarity algorithms for vector search.

Algorithm	Description
COSINE_SIMILARITY	Cosine similarity (good for text)
EUCLIDEAN_DISTANCE	Euclidean distance (L2 norm)
DOT_PRODUCT	Dot product similarity

import { Algorithm } from "ahnlich-client-node/grpc/algorithm/algorithm_pb";

const algo = Algorithm.COSINE_SIMILARITY;

NonLinearAlgorithm

Non-linear indexing algorithms for faster similarity search.

Algorithm	Description
KDTree	K-dimensional tree (lower dimensions)
HNSW	Hierarchical Navigable Small World (high dimensions)

import { NonLinearAlgorithm, KDTreeConfig, HNSWConfig } from "ahnlich-client-node/grpc/algorithm/nonlinear_pb";

const algo = NonLinearAlgorithm.HNSW;