@reactive-agents/prompts

Prompt management for the Reactive Agents framework. v0.10.3

A version-controlled template engine with {{variable}} interpolation, type-safe variable bindings, and a built-in library of agent prompts covering reasoning strategies (ReAct, Plan-Execute, Tree-of-Thought, Reflexion), evaluation judges (accuracy, relevance, completeness, safety), and tier-adaptive system prompts (frontier vs. local models).

Installation

bun add @reactive-agents/prompts

Or via the umbrella:

bun add reactive-agents

Features

• Template engine — {{variable}} interpolation with required/optional variables, defaults, and type guards
• Built-in template library — reasoning, verification, evaluation, and default agent system prompts
• Tier-adaptive variants — separate react-system-frontier, react-system-local, react-thought-frontier, react-thought-local for cost-aware prompt routing
• Version-controlled — every template carries a version integer; PromptService looks up the latest unless pinned
• Token estimator — estimateTokens() for budget planning before render
• A/B experiments — ExperimentService (unstable) for prompt variant evaluation

Quick Example

import { interpolate } from "@reactive-agents/prompts";

const rendered = interpolate(
  "You are a {{role}} expert. Answer in {{language}}.",
  { role: "TypeScript", language: "English" },
);

Built-in Templates

Reasoning

| Template | Strategy / phase | | ----------------------------------------- | ----------------------------------------- | | reactTemplate | High-level ReAct loop prompt | | reactSystemTemplate | ReAct system prompt | | reactThoughtTemplate | ReAct thought-step prompt | | reactSystemFrontierTemplate / reactSystemLocalTemplate | Tier-adaptive system variants | | reactThoughtFrontierTemplate / reactThoughtLocalTemplate | Tier-adaptive thought variants | | planExecuteTemplate | Plan-Execute high-level | | planExecutePlanTemplate | Plan phase | | planExecuteExecuteTemplate | Execute phase | | planExecuteReflectTemplate | Reflect phase | | treeOfThoughtTemplate | ToT high-level | | treeOfThoughtExpandTemplate | Expand candidate thoughts | | treeOfThoughtScoreTemplate | Score candidates | | treeOfThoughtSynthesizeTemplate | Synthesize chosen branch | | reflexionTemplate | Reflexion high-level | | reflexionGenerateTemplate | Generate attempt | | reflexionCritiqueTemplate | Critique prior attempt | | adaptiveClassifyTemplate | Classify task complexity for routing |

Verification

| Template | Use | | ------------------- | -------------------------------- | | factCheckTemplate | Fact-check decomposed claims |

Evaluation (judges)

| Template | Dimension | | ------------------------------ | --------------- | | judgeAccuracyTemplate | Accuracy | | judgeRelevanceTemplate | Relevance | | judgeCompletenessTemplate | Completeness | | judgeSafetyTemplate | Safety | | judgeGenericTemplate | Generic rubric |

Agent

| Template | Use | | ------------------------- | --------------------------------------- | | defaultSystemTemplate | Default agent system prompt |

allBuiltinTemplates is a flat array of every template above — useful for bulk registration.

Builder Integration

import { ReactiveAgents } from "reactive-agents";

// Enable all built-in templates
const agent = await ReactiveAgents.create()
  .withName("researcher")
  .withProvider("anthropic", { model: "claude-sonnet-4-20250514" })
  .withPrompts()
  .build();

// Or register custom templates at build time
const customAgent = await ReactiveAgents.create()
  .withName("custom")
  .withProvider("anthropic")
  .withPrompts({
    templates: [
      {
        id: "custom.system",
        name: "Custom System Prompt",
        version: 1,
        template: "You are a {{role}} expert. Answer in {{language}}.",
        variables: [
          { name: "role", required: true, type: "string" },
          { name: "language", required: false, type: "string", defaultValue: "English" },
        ],
      },
    ],
  })
  .build();

Direct Service Usage

import { Effect } from "effect";
import { PromptService, PromptServiceLive } from "@reactive-agents/prompts";

const program = Effect.gen(function* () {
  const prompts = yield* PromptService;
  const compiled = yield* prompts.compile("react.system", {
    role: "research assistant",
    tools: ["web_search", "calculator"],
  });
  return compiled.text;
});

A/B Experiments (unstable)

import { ExperimentService } from "@reactive-agents/prompts";
// Variant assignment, outcome capture, results aggregation.
// See AUDIT-overhaul-2026.md §11 #41 — surface may change in v0.10.x.

Key Exports

| Export | Purpose | | ------------------------------------------------ | ---------------------------------------------- | | PromptService, PromptServiceLive | Template registration + compilation | | interpolate, estimateTokens | Pure template-engine helpers | | allBuiltinTemplates | Bulk registration array | | createPromptLayer | Factory for the runtime layer | | ExperimentService, ExperimentServiceLive | A/B experimentation (unstable) | | PromptTemplate, CompiledPrompt, PromptVariable | Schemas + types | | PromptError, TemplateNotFoundError, VariableError | Tagged errors |

Documentation

Full documentation at docs.reactiveagents.dev

License

MIT