Molecule.dev

@molecule/api-ai-anthropic

Provider bond · ai · API (Node) · v1.3.5 · Apache-2.0

Anthropic Claude AI provider for molecule.dev

npm install @molecule/api-ai-anthropic

npm · Source on GitHub · Implements @molecule/api-ai

How it works

@molecule/api-ai-anthropic is a provider bond on the API (Node) side: it implements the ai core interface (@molecule/api-ai) with a concrete vendor or library behind it.

Your code calls the core; you wire this provider once at startup. Swapping vendors later is one line in that wiring, not a rewrite.

// npm install @molecule/api-ai-anthropic --workspace=api
import { setProvider, requireProvider } from '@molecule/api-ai'
import { provider } from '@molecule/api-ai-anthropic'

// Named registration — several AI providers can be bonded side by side
// (getProviderByName('anthropic') targets this one); the FIRST one
// registered also answers requireProvider() (see @molecule/api-ai).
setProvider('anthropic', provider) // reads ANTHROPIC_API_KEY from the environment

let reply = ''
for await (const event of requireProvider().chat({
  messages: [{ role: 'user', content: 'Hello!' }],
})) {
  if (event.type === 'text') reply += event.content // or forward the chunk to the client (SSE)
}

Works with: @molecule/api-bond, @molecule/api-i18n, @molecule/api-secrets

Secrets: ANTHROPIC_API_KEY

Live demos

Running apps built with Molecule that install this package — open the app or study the template.

Reference

Anthropic ai-anthropic provider for molecule.dev.

Auto-generated, AI-first package reference for the molecule.dev ecosystem. It is written to be read by coding agents as much as by people, and is generated from this package's source — edit src/index.ts JSDoc, not this file.

Quick Start

// npm install @molecule/api-ai-anthropic --workspace=api
import { setProvider, requireProvider } from '@molecule/api-ai'
import { provider } from '@molecule/api-ai-anthropic'

// Named registration — several AI providers can be bonded side by side
// (getProviderByName('anthropic') targets this one); the FIRST one
// registered also answers requireProvider() (see @molecule/api-ai).
setProvider('anthropic', provider) // reads ANTHROPIC_API_KEY from the environment

let reply = ''
for await (const event of requireProvider().chat({
  messages: [{ role: 'user', content: 'Hello!' }],
})) {
  if (event.type === 'text') reply += event.content // or forward the chunk to the client (SSE)
}

Type

provider

Installation

npm install @molecule/api-ai-anthropic @molecule/api-ai @molecule/api-bond @molecule/api-i18n @molecule/api-secrets

API

Interfaces

AnthropicConfig

Configuration for anthropic.

interface AnthropicConfig {
  /** API key. Defaults to ANTHROPIC_API_KEY env var. */
  apiKey?: string
  /** Default model. Defaults to 'claude-opus-5-5'. */
  defaultModel?: string
  /** Maximum tokens for completions. */
  maxTokens?: number
  /** Base URL override (for proxies). */
  baseUrl?: string
  /** Called on each rate-limited/overloaded upstream response, before any retry sleep. */
  onRateLimit?: AiRateLimitCallback
}

ProcessEnv

Process Env interface.

interface ProcessEnv {
  ANTHROPIC_API_KEY: string
  /** Base URL override (for credential brokers / gateways). */
  ANTHROPIC_BASE_URL?: string
}

Functions

createProvider(config)

Creates an Anthropic Claude AI provider instance.

function createProvider(config?: AnthropicConfig): AIProvider
  • config — Anthropic-specific configuration (API key, model, max tokens, base URL).

Returns: An AIProvider backed by the Anthropic Messages API.

Constants

provider

The provider implementation.

const provider: AIProvider

aiAnthropicSecretDefinitions

Secret definitions required by the Anthropic AI bond.

const aiAnthropicSecretDefinitions: SecretDefinition[]

Core Interface

Implements @molecule/api-ai interface.

Bond Wiring

Setup function to register this provider with the bond system:

import { bond } from '@molecule/api-bond'
import { provider } from '@molecule/api-ai-anthropic'

export function setupAiAnthropic(): void {
  bond('ai', 'anthropic', provider)
}

Injection Notes

Requirements

Peer dependencies:

  • @molecule/api-ai ^1.0.1
  • @molecule/api-bond ^1.0.1
  • @molecule/api-i18n ^1.0.1
  • @molecule/api-secrets ^1.0.1

Environment Variables

Runtime Dependencies

  • @molecule/api-ai
  • @molecule/api-bond
  • @molecule/api-i18n
  • @molecule/api-secrets

Bond this as an AI provider (see @molecule/api-ai for the chat() streaming loop and the key-server-side / never-blindly-trust-model-output rules). Config: ANTHROPIC_API_KEY (SERVER-side only — never shipped to the browser) plus an optional default model id. Drive it through the core chat() / requireProvider(), NOT the Anthropic SDK directly, so the app stays provider-agnostic and can swap models/providers by changing only the bond.

Missing ANTHROPIC_API_KEY fails fast: the provider throws naming the exact env var on first use (the exported provider is a lazy proxy, so this fires on the first chat() call, not at bond/module-load time) — it never silently sends an empty key and surfaces only as a generic 401 later.

Error message disambiguation: a non-OK response yields a sanitized error ChatEvent (never a throw). A permanently-invalid request — a plain 400 that ISN'T a context-length error (bad param, malformed tool schema) — gets its own non-retryable message ("AI request was invalid — check the model and request parameters.") distinct from the generic "AI service error. Please try again." used for retryable failures; don't retry a plain 400 as if it might succeed on a second attempt.

E2E Tests

Integration checklist — drive the real UI (live preview, no mocks), adapt each item to this app's actual chat/AI screens, and check every box off one by one. A box you can't check is an integration bug to fix — not a skip. The sandbox HAS an AI provider bonded, so the flow runs live end-to-end; AI output is NON-DETERMINISTIC, so assert on STRUCTURE/behavior, not exact text:

  • A message sent through the real chat UI comes back as a RELEVANT AI reply — not an echo of the prompt, a hardcoded stub, or an empty bubble. Ask something with a checkable answer (e.g. "What is 2 + 2?") and confirm the response actually contains it ("4"), proving a live model answered.
  • If the app streams, tokens render INCREMENTALLY — text grows word by word in the UI, not one final blob dumped after a long frozen spinner. (A streamed chat() yields text chunks then a final done; a single late blob means the reply was awaited whole and streaming is broken.)
  • Multi-turn CONTEXT is preserved: a follow-up that refers back to the previous turn (e.g. after "2 + 2", ask "now double that" -> understood as 8) works — proving the full messages history is sent, not just the last line.
  • A provider failure (bad/missing key, rate limit, timeout) surfaces as a graceful in-UI error message, NOT a crash, blank screen, a spinner that never resolves, or an unhandled 500. Force one and watch the UI recover.
  • The provider key + the provider call are SERVER-side only: the key never reaches the browser (check the network tab, the JS bundle, and page globals), and no route proxies arbitrary prompts to the model without auth
    • a token cap — an open AI endpoint is an unbounded bill and abuse vector.

Translations

Translation strings are provided by @molecule/api-locales-ai-anthropic.