@deepagents/context

A domain-agnostic context management system for formatting context fragments into different prompt styles.

Overview

This package provides a flexible way to compose and render context data in multiple formats (XML, Markdown, TOML, TOON). Context fragments are simple data structures that can be transformed into different representations suitable for various LLM prompt styles.

Installation

npm install @deepagents/context

Basic Usage

import { XmlRenderer, guardrail, hint, term } from '@deepagents/context';

// Create fragments using builder functions
const fragments = [
  term('MRR', 'monthly recurring revenue'),
  hint('Always exclude test accounts'),
  guardrail({
    rule: 'Never expose PII',
    reason: 'Privacy compliance',
    action: 'Aggregate data instead',
  }),
];

// Render to XML
const renderer = new XmlRenderer({ groupFragments: true });
console.log(renderer.render(fragments));

Output:

<terms>
  <term>
    <name>MRR</name>
    <definition>monthly recurring revenue</definition>
  </term>
</terms>
<hints>
  <hint>Always exclude test accounts</hint>
</hints>
<guardrails>
  <guardrail>
    <rule>Never expose PII</rule>
    <reason>Privacy compliance</reason>
    <action>Aggregate data instead</action>
  </guardrail>
</guardrails>

Fragment Builders

Domain Fragments

Builder functions for injecting domain knowledge into prompts:

| Function | Description | Example | | --------------------------------------------- | -------------------------------- | --------------------------------------------------- | | term(name, definition) | Define business vocabulary | term('NPL', 'non-performing loan') | | hint(text) | Behavioral rules and constraints | hint('Always filter by status') | | guardrail({rule, reason?, action?}) | Safety rules and boundaries | guardrail({ rule: 'No PII' }) | | explain({concept, explanation, therefore?}) | Rich concept explanations | explain({ concept: 'churn', explanation: '...' }) | | example({question, answer, note?}) | Question-answer pairs | example({ question: '...', answer: '...' }) | | clarification({when, ask, reason}) | When to ask for more info | clarification({ when: '...', ask: '...' }) | | workflow({task, steps, triggers?, notes?}) | Multi-step processes | workflow({ task: '...', steps: [...] }) | | quirk({issue, workaround}) | Data edge cases | quirk({ issue: '...', workaround: '...' }) | | styleGuide({prefer, never?, always?}) | Style preferences | styleGuide({ prefer: 'CTEs' }) | | analogy({concepts, relationship, ...}) | Concept comparisons | analogy({ concepts: [...], relationship: '...' }) | | glossary(entries) | Term-to-expression mapping | glossary({ revenue: 'SUM(amount)' }) |

User Fragments

Builder functions for user-specific context:

| Function | Description | Example | | ------------------------------------ | ---------------------------- | ---------------------------------------------- | | identity({name?, role?}) | User identity | identity({ role: 'VP Sales' }) | | persona({name, role, tone?}) | AI persona definition | persona({ name: 'Freya', role: '...' }) | | alias(term, meaning) | User-specific vocabulary | alias('revenue', 'gross revenue') | | preference(aspect, value) | Output preferences | preference('date format', 'YYYY-MM-DD') | | userContext(description) | Current working focus | userContext('Q4 analysis') | | correction(subject, clarification) | Corrections to understanding | correction('status', '1=active, 0=inactive') |

Core Utilities

| Function | Description | | ----------------------------- | ---------------------------------------------- | | fragment(name, ...children) | Create a wrapper fragment with nested children | | role(content) | System role/instructions fragment |

Renderers

All renderers support the groupFragments option which groups same-named fragments under a pluralized parent tag.

XmlRenderer

Renders fragments as XML with proper nesting and escaping:

const renderer = new XmlRenderer({ groupFragments: true });

<styleGuide>
  <prefer>CTEs</prefer>
  <never>subqueries</never>
</styleGuide>

MarkdownRenderer

Renders fragments as Markdown with bullet points:

const renderer = new MarkdownRenderer();

## Style Guide

- **prefer**: CTEs
- **never**: subqueries

TomlRenderer

Renders fragments as TOML-like format:

const renderer = new TomlRenderer();

[styleGuide]
prefer = "CTEs"
never = "subqueries"

ToonRenderer

Token-efficient format with CSV-style tables for uniform arrays:

const renderer = new ToonRenderer();

styleGuide:
  prefer: CTEs
  never: subqueries

Handling Complex Data

Arrays

const fragment = workflow({
  task: 'Analysis',
  steps: ['step1', 'step2', 'step3'],
});

XML Output:

<workflow>
  <task>Analysis</task>
  <steps>
    <step>step1</step>
    <step>step2</step>
    <step>step3</step>
  </steps>
</workflow>

Nested Objects

const fragment = {
  name: 'database',
  data: {
    host: 'localhost',
    settings: {
      timeout: 30,
      retry: true,
    },
  },
};

XML Output:

<database>
  <host>localhost</host>
  <settings>
    <timeout>30</timeout>
    <retry>true</retry>
  </settings>
</database>

Null and Undefined Values

All renderers automatically skip null and undefined values.

API Reference

Interfaces

ContextFragment

interface ContextFragment {
  name: string;
  data: FragmentData;
  type?: 'fragment' | 'message';
  persist?: boolean;
  codec?: FragmentCodec;
}

ContextRenderer

abstract class ContextRenderer {
  abstract render(fragments: ContextFragment[]): string;
}

Classes

All renderer classes extend ContextRenderer:

• XmlRenderer - Renders as XML
• MarkdownRenderer - Renders as Markdown
• TomlRenderer - Renders as TOML
• ToonRenderer - Token-efficient format

License

MIT