@zhivex-ai/anthropic

Anthropic adapter for Zhivex AI SDK, with first-class Claude Opus 5 support.

Install

bun add @zhivex-ai/core @zhivex-ai/anthropic

Claude Opus 5

import { generateText } from "@zhivex-ai/core";
import { createAnthropic } from "@zhivex-ai/anthropic";

const anthropic = createAnthropic({
  apiKey: process.env.ANTHROPIC_API_KEY
});

const result = await generateText({
  model: anthropic("claude-opus-5"),
  prompt: "Review this architecture and identify the highest-risk assumption.",
  maxTokens: 64_000,
  reasoning: {
    effort: "xhigh"
  }
});

console.log(result.text);

The model advertises the complete shared effort ladder: none, low, medium, high, xhigh, and max. Omitting reasoning leaves Opus 5's default adaptive thinking untouched. none maps to thinking.disabled; disabling thinking with xhigh or max is rejected before the network request. Manual thinking budgets, non-default sampling, and assistant prefills are also rejected locally.

Native structured output is available through generateObject() and streamObject() across current Claude families, including Opus 5, Sonnet 5, Fable/Mythos 5, Opus 4.6–4.8, Sonnet 4.5–4.6, and Haiku 4.5. The adapter maps the shared schema to output_config.format without a legacy beta header.

Provider-specific Opus 5 controls are typed:

const result = await generateText({
  model: anthropic("claude-opus-5"),
  prompt: "Run the task within the declared token budget.",
  maxTokens: 64_000,
  reasoning: { effort: "max" },
  providerOptions: {
    fallbacks: "default",
    output_config: {
      task_budget: {
        type: "tokens",
        total: 64_000,
        remaining: 48_000
      }
    },
    midConversationToolChanges: true
  }
});

The adapter automatically adds and composes the beta headers required for task budgets, managed or explicit server-side fallbacks, mid-conversation tool changes, MCP, and Files API. Set providerOptions.speed = "fast" only when Anthropic has enabled the premium fast-mode research preview for the account; the adapter then adds fast-mode-2026-02-01.

Usage maps uncached input, cache reads, cache writes, output, thinking tokens, total tokens, and the reported standard/fast speed. Unknown provider-native blocks—including fallback metadata—are preserved as provider-data.

The package also supports current Claude families such as Claude Sonnet 5, Claude Fable 5, Claude Mythos 5, Claude Opus 4.8, and Claude Haiku 4.5, with model-specific capability validation. Models that reject assistant-prefilled conversations fail locally before an API request is attempted.

Authenticated Anthropic requests reject redirects so a 307 or 308 cannot replay x-api-key or the prompt body to another origin. The adapter's explicit rawFetch escape hatch remains uncredentialed.

Official references:

• Claude Opus 5
• Effort
• Thinking
• Structured outputs
• Fast mode

Repository and full documentation:

• https://github.com/Zhivex/zhivex-ai-sdk