Anthropic

Anthropic offers 14 models through Lava’s AI Gateway, supporting Chat Completions (Native). Authentication uses x-api-key with default anthropic-version header. See the Anthropic API docs for provider-specific parameters.

Supports both managed (Lava’s API keys) and unmanaged (bring your own credentials) mode.

Quick Start

const response = await fetch('https://api.lava.so/v1/forward?u=https%3A%2F%2Fapi.anthropic.com%2Fv1%2Fmessages', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    Authorization: `Bearer ${forwardToken}`,
  },
  body: JSON.stringify({
    model: 'claude-fable-5',
    messages: [{ role: "user", content: "Hello!" }],
  }),
});

Chat Completions (Native)

Target URL: https://api.anthropic.com/v1/messages


Content Type	`application/json`
Streaming	Yes (set `stream: true` in request body)

Model	Input / 1M tokens	Output / 1M tokens
claude-opus-4-1	$15.00	$75.00
claude-opus-4-1-20250805	$15.00	$75.00
claude-fable-5	$10.00	$50.00
claude-opus-4-8	$5.00	$25.00
claude-opus-4-7	$5.00	$25.00
claude-opus-4-6	$5.00	$25.00
claude-opus-4-5	$5.00	$25.00
claude-opus-4-5-20251101	$5.00	$25.00
claude-sonnet-5	$3.00	$15.00
claude-sonnet-4-6	$3.00	$15.00
claude-sonnet-4-5	$3.00	$15.00
claude-sonnet-4-5-20250929	$3.00	$15.00
claude-haiku-4-5	$1.00	$5.00
claude-haiku-4-5-20251001	$1.00	$5.00

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