ModelPart

CORE · type · Type contract

One streamed response part: assistant text or a function-call fragment.

Import

TypeScript

import type { ModelPart } from '@jangts/agent-core';

JavaScript

/** @typedef {import('@jangts/agent-core').ModelPart} ModelPart */

Other public entry points:@jangts/agent-core, @jangts/agent-core/types, @jangts/agent-core/structs.

Definition

Type: ModelPart

Type expression

type ModelPart = string | FunctionCallDelta;

Union branch structure

Optional shapes of ModelPart: choose one shape; required fields for each branch are listed separately.

Branch 1

string

Branch 2

Field	Type	Required	Description
type	"function-call-delta"	Required	See the type definition and usage context.
index	number	Required	Index of the call within the response; deltas with the same index belong together.
id	string | undefined	Optional	Provider call id, usually delivered once with the first delta.
name	string | undefined	Optional	Function name, usually delivered once with the first delta.
arguments	string | undefined	Optional	Raw JSON argument fragment; concatenating all fragments yields the full arguments.

Examples

• Model tools and transports: typed selection only after full validation: A tool definition provides a Schema and resolver; a transport translates wire output into the unified model selection contract.
• Compatible Provider and custom Providers: Support owns the common Chat Completions HTTP/SSE lifecycle; an App can substitute its own ChatProvider.
• Support: the aggregate entry for recommended usage: Support aggregates recommended construction, policies, and same-source configuration generation; Core execution does not depend on this namespace.

Declare two selectable tools

Beginner · Node.js

TypeScript

import { ModelToolRegistry } from '@jangts/agent-core';
const inputSchema = { jsonSchema: { type: 'object', properties: {}, additionalProperties: false },
  parse(value: unknown) {
    if (!value || typeof value !== 'object' || Array.isArray(value) || Object.keys(value).length) throw new Error('需要空对象');
    return {};
  } };
const tools = new ModelToolRegistry([
  { id: 'greet', description: '回答问候', inputSchema, resolve: () => 'greet' },
  { id: 'status', description: '查询状态', inputSchema, resolve: () => 'status' },
]).seal();
console.log(tools.resolve({ toolId: 'status', input: {} }, { stageId: 'recognize' }));

JavaScript

import { ModelToolRegistry } from '@jangts/agent-core';
const inputSchema = { jsonSchema: { type: 'object', properties: {}, additionalProperties: false },
    parse(value) {
        if (!value || typeof value !== 'object' || Array.isArray(value) || Object.keys(value).length)
            throw new Error('需要空对象');
        return {};
    } };
const tools = new ModelToolRegistry([
    { id: 'greet', description: '回答问候', inputSchema, resolve: () => 'greet' },
    { id: 'status', description: '查询状态', inputSchema, resolve: () => 'status' },
]).seal();
console.log(tools.resolve({ toolId: 'status', input: {} }, { stageId: 'recognize' }));

Project an allowed subset to only one stage

Configuration · Node.js

TypeScript

import { ModelToolRegistry, Support } from '@jangts/agent-core';
const schema = Support.defineSchema({ jsonSchema: { type: 'object', properties: {} },
  parse(value: unknown) { if (!value || typeof value !== 'object' || Array.isArray(value)) throw new TypeError('需要对象'); return {}; } });
const registry = new ModelToolRegistry([
  { id: 'greet', description: '问候', inputSchema: schema, resolve: () => 'greet' },
  { id: 'status', description: '状态', inputSchema: schema, resolve: () => 'status' },
]).seal();
const readOnly = registry.select(['status']);
const transport = Support.createModelTransport({ id: 'recognize', tools: readOnly });
console.log(transport.id, readOnly.ids());

JavaScript

import { ModelToolRegistry, Support } from '@jangts/agent-core';
const schema = Support.defineSchema({ jsonSchema: { type: 'object', properties: {} },
    parse(value) { if (!value || typeof value !== 'object' || Array.isArray(value))
        throw new TypeError('需要对象'); return {}; } });
const registry = new ModelToolRegistry([
    { id: 'greet', description: '问候', inputSchema: schema, resolve: () => 'greet' },
    { id: 'status', description: '状态', inputSchema: schema, resolve: () => 'status' },
]).seal();
const readOnly = registry.select(['status']);
const transport = Support.createModelTransport({ id: 'recognize', tools: readOnly });
console.log(transport.id, readOnly.ids());

Related policy source

• HTTP failure mapping and controlled request fields

Related definitions

• FunctionCallDelta