reciprocalRankFusion

KIT · function · Runtime value

Fuse ranked lists with one-based reciprocal rank fusion.

Raw retriever scores are intentionally not mixed. Ties break on id, so the output is deterministic for a given input.

Import

TypeScript

import { reciprocalRankFusion } from '@jangts/agent-core/kits/rank-fusion';

JavaScript

import { reciprocalRankFusion } from '@jangts/agent-core/kits/rank-fusion';

Other public entry points:@jangts/agent-core/types, @jangts/agent-core/kits, @jangts/agent-core/kits/rank-fusion.

Definition

Call

reciprocalRankFusion(lists: readonly RankedList[], options: { limit: number; k?: number; }): FusedRank[]

Fuse ranked lists with one-based reciprocal rank fusion.

Raw retriever scores are intentionally not mixed. Ties break on id, so the output is deterministic for a given input.

Parameter	Type	Passing	Description
lists	readonly RankedList[]	Required	—
options	{ limit: number; k?: number; }	Required	—

Fields of options

Field	Type	Required	Description
limit	number	Required	See the type definition and usage context.
k	number | undefined	Optional	See the type definition and usage context.

Returns: FusedRank[].

Examples

• Rank Fusion: fuse multiple retrieval results by rank: Fuse full-text and vector ranks instead of directly adding raw scores with different semantics.

First use the default fusion parameters

Beginner · Node.js

TypeScript

import { reciprocalRankFusion } from '@jangts/agent-core/kits/rank-fusion';
const result = reciprocalRankFusion([
  { sourceId: 'text', ids: ['workflow', 'model'] },
  { sourceId: 'vector', ids: ['model', 'workflow'] },
], { limit: 5 });
console.log(result);

JavaScript

import { reciprocalRankFusion } from '@jangts/agent-core/kits/rank-fusion';
const result = reciprocalRankFusion([
    { sourceId: 'text', ids: ['workflow', 'model'] },
    { sourceId: 'vector', ids: ['model', 'workflow'] },
], { limit: 5 });
console.log(result);

Add source weights and the smoothing parameter to the same function

Configuration · Node.js

TypeScript

import { reciprocalRankFusion } from '@jangts/agent-core/kits/rank-fusion';
const result = reciprocalRankFusion([
  { sourceId: 'text', ids: ['workflow', 'model'], weight: 2 },
  { sourceId: 'vector', ids: ['model', 'workflow'], weight: 1 },
], { limit: 2, k: 30 });
console.log(result[0].contributions);

JavaScript

import { reciprocalRankFusion } from '@jangts/agent-core/kits/rank-fusion';
const result = reciprocalRankFusion([
    { sourceId: 'text', ids: ['workflow', 'model'], weight: 2 },
    { sourceId: 'vector', ids: ['model', 'workflow'], weight: 1 },
], { limit: 2, k: 30 });
console.log(result[0].contributions);

Related policy source

• RRF ranks, deduplication, and scores

Related definitions

• FusedRank
• RankedList