How to Use the OpenRouter API
Access GPT, Claude, Gemini & More (2026 Guide)

What Is OpenRouter? One API for GPT, Claude, and Gemini

OpenRouter is a unified LLM API gateway: one API key plus one OpenAI-compatible endpoint reaches 70+ providers and 400+ models (GPT, Claude, Gemini, Llama, DeepSeek, Qwen, Mistral, and more) without separate accounts, SDK forks, or split billing dashboards.

• Unified endpoint: https://openrouter.ai/api/v1/chat/completions
• Authentication: Authorization: Bearer $OPENROUTER_API_KEY
• Protocol: OpenAI Chat Completions format — existing OpenAI SDK code usually needs only a new base_url and api_key
• Model IDs: provider/model, e.g. openai/gpt-4o, anthropic/claude-3.5-sonnet, google/gemini-2.5-pro, deepseek/deepseek-chat

Dual routing: Model Routing + Provider Routing

OpenRouter makes two independent routing decisions — understanding both is key to using the platform well:

On top of that, automatic fallback kicks in when a primary provider rate-limits or errors — OpenRouter can fail over to the next provider or model in your models array so your app does not surface a raw 500.

Six pain points developers hit before OpenRouter

1. 01

   Fragmented vendor accounts: OpenAI, Anthropic, and Google each need separate signup, key rotation, and SDK quirks — painful when agent frameworks swap models frequently.

2. 02

   Single-vendor outages: Direct API calls force you to build circuit breakers, retries, and backoff yourself.

3. 03

   Split billing: Five dashboards for spend, latency, and cost make finance reconciliation slow for small teams.

4. 04

   Hidden token markups: Many aggregators inflate per-token prices, making long-run cost opaque.

5. 05

   Extra gateway latency: OpenRouter adds roughly 10–80ms per hop — unacceptable for some real-time paths.

6. 06

   Compliance middle layer: Traffic transits a US-based third party, which may conflict with strict data residency rules.

Step-by-Step: Integrate the OpenRouter API in 6 Steps

1. 01

   Create an account: Sign up at openrouter.ai with GitHub or email.

2. 02

   Generate an API key: Open the Keys page, create a key, and store it securely — it is shown once.

3. 03

   Add credits (optional): Paid models need credits; free models work within daily limits without a top-up.

4. 04

   Send a test request: Validate your key with the curl or SDK samples below.

5. 05

   Migrate existing OpenAI SDK code: Point base_url and api_key at OpenRouter; add HTTP-Referer and X-Title headers for leaderboard attribution.

6. 06

   Deploy a production fallback chain: Configure a models array with route: "fallback"; refresh availability via GET /api/v1/models.

cURL request

curl https://openrouter.ai/api/v1/chat/completions \
  -H "Authorization: Bearer $OPENROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "anthropic/claude-3.5-sonnet",
    "messages": [
      { "role": "user", "content": "Explain quantum computing in one sentence" }
    ]
  }'

Python (requests)

import requests, os

response = requests.post(
    url="https://openrouter.ai/api/v1/chat/completions",
    headers={
        "Authorization": f"Bearer {os.environ['OPENROUTER_API_KEY']}",
        "Content-Type": "application/json",
    },
    json={
        "model": "google/gemini-2.5-pro",
        "messages": [{"role": "user", "content": "Write a quicksort in Python"}],
    },
)
print(response.json()["choices"][0]["message"]["content"])

Python (OpenAI SDK drop-in — recommended)

from openai import OpenAI
import os

client = OpenAI(
    base_url="https://openrouter.ai/api/v1",
    api_key=os.environ["OPENROUTER_API_KEY"],
)

completion = client.chat.completions.create(
    model="openai/gpt-4o",
    messages=[{"role": "user", "content": "Hello!"}],
    extra_headers={
        "HTTP-Referer": "https://your-blog-domain.com",
        "X-Title": "My Blog Demo",
    },
)
print(completion.choices[0].message.content)

Node.js (OpenAI SDK)

import OpenAI from "openai";

const openai = new OpenAI({
  baseURL: "https://openrouter.ai/api/v1",
  apiKey: process.env.OPENROUTER_API_KEY,
});

const completion = await openai.chat.completions.create({
  model: "deepseek/deepseek-chat",
  messages: [{ role: "user", content: "Explain OpenRouter in one sentence" }],
});
console.log(completion.choices[0].message.content);

Streaming output

const stream = await openai.chat.completions.create({
  model: "anthropic/claude-3.5-sonnet",
  messages: [{ role: "user", content: "Write a short poem about autumn" }],
  stream: true,
});

for await (const chunk of stream) {
  const content = chunk.choices[0]?.delta?.content;
  if (content) process.stdout.write(content);
}

Multi-model fallback configuration

{
  "model": "anthropic/claude-3.5-sonnet",
  "models": [
    "anthropic/claude-3.5-sonnet",
    "openai/gpt-4o",
    "google/gemini-2.5-pro"
  ],
  "route": "fallback",
  "messages": [{ "role": "user", "content": "Hello" }]
}

List available models

curl https://openrouter.ai/api/v1/models \
  -H "Authorization: Bearer $OPENROUTER_API_KEY"

Bilingual SEO: Why English Pages Underperform + Fix Checklist

If you run OpenRouter-powered agents and maintain a bilingual technical blog, low English traffic is rarely one problem. This checklist ranks fixes by ROI:

P0: Crawl and index (most overlooked)

• CDN/WAF blocking Googlebot: Geo-restricted CDNs may treat crawlers as attack traffic — verify fetch in Google Search Console URL Inspection.
• Missing hreflang: Google may index only the Chinese URL and treat English as duplicate. Use /zh/ and /en/ subdirectories with reciprocal hreflang="zh-Hans" and hreflang="en", plus x-default.
• robots.txt / noindex mistakes: Confirm /en/ is not disallowed.
• Sitemap gaps: List each locale separately with <xhtml:link> alternates.
• CSR shell pages: Client-only rendering can return empty HTML to crawlers — prefer SSG/SSR for articles.

P1: Content — localize, do not translate

English searchers rarely type "OpenRouter advantages." They ask "OpenRouter vs OpenAI API" or "is OpenRouter worth it." In 2026, AI Mode fan-out splits one query into sub-intents — your page must answer what it is, how to integrate, pricing, comparisons, safety, and limits.

Structured data (Schema)

Ship at least BlogPosting/TechArticle plus FAQPage JSON-LD. FAQ questions should mirror real speech — e.g. "Is OpenRouter free?" not "Free usage of OpenRouter." Keep Chinese FAQ phrasing on the zh URL.

Distribution channels

Action checklist and metrics

• P0 this week: GSC index check for English URLs, CDN/WAF audit, hreflang + canonical + sitemap fixes
• P1 writing: Independent zh/en drafts (shared code, localized prose) with Article + FAQPage Schema
• P2 distribution: Chinese posts to Juejin/Zhihu/V2EX; English cross-post to dev.to; submit both sitemaps
• Tracking: Split GSC by /en/ vs /zh/ — zero impressions means indexing; high impressions + low CTR means title/description; monitor organic traffic and bounce rate per locale

Hard numbers for citations (EEAT)

• Catalog size: 70+ providers, 400+ models, one endpoint and one key
• Gateway latency: roughly 10–80ms extra vs direct vendor APIs
• Credit fee: 5.5% (minimum $0.80); BYOK first 1M requests/month free of service fees
• Free tier: ~50 requests/day without top-up; $10+ credits unlocks 1000/day and 20/minute

OpenRouter excels at multi-model agent prototypes, but production agents that need 24/7 uptime, stable SSH sessions, and native iOS/macOS build tooling hit hard limits on Linux VPS hosts — no Metal, no Xcode, isolated Keychain. For iOS CI/CD and always-on agent automation, NodeMini cloud Mac Mini rental is usually the better production layer: dedicated Apple Silicon, second-scale provisioning, pay-as-you-go like a VPS. See rental pricing and the help center for SSH setup and node isolation.