Anthropic

Anthropic builds the Claude family of models. Its Messages API is one of the handful of first-party dialects in the world — requests use a `system` field separate from `messages`, content blocks rather than plain strings, and a server-sent event stream of typed deltas. The gateway translates OpenAI-shaped requests into it and the response stream back out, byte by byte.

Documentation Status Pricing Privacy

Models: 11
From: $1 per 1M in
Largest context: 1M tokens
Dialect: anthropic

Get API key Browse all models

index.ts

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.onefoldhq.com/v1",
  apiKey: process.env.ONEFOLD_API_KEY,
});

const result = await client.chat.completions.create({
  model: "anthropic/claude-opus-5",
  messages: [{ role: "user", content: "Why is the sky blue?" }],
});

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.onefoldhq.com/v1",
  apiKey: process.env.ONEFOLD_API_KEY,
});

const result = await client.chat.completions.create({
  model: "anthropic/claude-opus-5",
  messages: [{ role: "user", content: "Why is the sky blue?" }],
});

request.sh

curl https://api.onefoldhq.com/v1/chat/completions \
  -H "Authorization: Bearer $ONEFOLD_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "anthropic/claude-opus-5",
    "messages": [{ "role": "user", "content": "Why is the sky blue?" }]
  }'

curl https://api.onefoldhq.com/v1/chat/completions \
  -H "Authorization: Bearer $ONEFOLD_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "anthropic/claude-opus-5",
    "messages": [{ "role": "user", "content": "Why is the sky blue?" }]
  }'

Read docs

Anthropic models

Every Anthropic model routable through Onefold. Sort by any column.

						Providers	Capabilities
anthropic/claude-opus-5	1M	128K	$5/1M	$25/1M	$0.50/1M	Anthropic	Adaptive thinkingHigh-res visionStructured outputsEffort controlFast mode
anthropic/claude-sonnet-5	1M	128K	$3/1M	$15/1M	$0.30/1M	Anthropic	Adaptive thinkingHigh-res visionStructured outputsEffort controlPrompt caching
anthropic/claude-haiku-4-5	200K	64K	$1/1M	$5/1M	$0.10/1M	Anthropic	Extended thinkingVisionStructured outputsPrompt cachingCitations
anthropic/claude-fable-5	1M	128K	$10/1M	$50/1M	$1/1M	Anthropic	Adaptive thinkingHigh-res visionStructured outputsEffort controlPrompt caching
anthropic/claude-opus-4-8	1M	128K	$5/1M	$25/1M	$0.50/1M	Anthropic	Adaptive thinkingHigh-res visionStructured outputsEffort controlFast mode
anthropic/claude-opus-4-7	1M	128K	$5/1M	$25/1M	$0.50/1M	Anthropic	Adaptive thinkingHigh-res visionEffort controlPrompt cachingCitations
anthropic/claude-opus-4-6	1M	128K	$5/1M	$25/1M	$0.50/1M	Anthropic	Adaptive thinkingExtended thinkingVisionEffort controlPrompt caching
anthropic/claude-sonnet-4-6	1M	128K	$3/1M	$15/1M	$0.30/1M	Anthropic	Adaptive thinkingExtended thinkingVisionEffort controlPrompt caching
anthropic/claude-opus-4-5	200K	64K	$5/1M	$25/1M	$0.50/1M	Anthropic	Extended thinkingVisionStructured outputsEffort controlPrompt caching
anthropic/claude-sonnet-4-5	200K	64K	$3/1M	$15/1M	$0.30/1M	Anthropic	Extended thinkingVisionPrompt cachingCitationsBatch API
anthropic/claude-opus-4-1Retiring	200K	32K	$15/1M	$75/1M	$1.50/1M	Anthropic	Extended thinkingVisionStructured outputsPrompt cachingCitations

Platforms

Where Anthropic models can be reached from. Onefold routes to whichever is available, and the request shape does not change between them.

Anthropicclaude-api

Bedrockbedrock

Google Vertex AIgoogle-cloud

About Anthropic

Anthropic speaks the anthropic dialect. You never write it — Onefold accepts OpenAI-shaped requests and translates them at the edge, streaming byte by byte rather than buffering. Anthropic is based in San Francisco, USA.

11 of its models are routable today, from $1 per million input tokens up to 1M of context. Switching between any of them means changing the model string and nothing else.