Open API

Overview

Ai4Scholar's Open API provides RESTful endpoints for developers to integrate paper, author, and citation-network queries into their applications. The Open Platform provides separate documentation for Semantic Scholar, PubMed, Google Scholar, and Google Patents. See the interactive API documentation for currently available endpoints, parameters, and response structures. This page covers the most common requests.

Authentication

Every API request must include an API key in the header:

Authorization: Bearer YOUR_API_KEY

All public endpoints use this authentication method. The x-api-key header is not supported. If you are referring to Semantic Scholar's official documentation, remember that its authentication instructions apply to its own API. Always use Authorization: Bearer when calling through Ai4Scholar.

Get an API key

1. After signing in, open the Open Platform, or open API key management through the developer settings in research mode.
2. Create a key and set a spending limit as needed.
3. Copy the key and store it securely. Use placeholders in public examples and frontend code, never real keys.

Common endpoints

These are common entry points, not the complete list. See the interactive API documentation for batch, autocomplete, snippet search, and other endpoints.

Request examples

Python

import requests
 
API_KEY = "sk-user-your-key-here"
BASE_URL = "https://ai4scholar.net/graph/v1"
 
response = requests.get(
    f"{BASE_URL}/paper/search",
    params={
        "query": "transformer attention mechanism",
        "limit": 10,
        "fields": "paperId,title,abstract,authors,year,citationCount"
    },
    headers={"Authorization": f"Bearer {API_KEY}"}
)
 
data = response.json()
for paper in data["data"]:
    print(f"{paper['title']} ({paper['year']}) - Citations: {paper['citationCount']}")

JavaScript

const API_KEY = 'sk-user-your-key-here';
const BASE_URL = 'https://ai4scholar.net/graph/v1';
 
const response = await fetch(
  `${BASE_URL}/paper/search?query=transformer&limit=5`,
  {
    headers: { Authorization: `Bearer ${API_KEY}` },
  },
);
 
const data = await response.json();
console.log(data);

cURL

curl "https://ai4scholar.net/graph/v1/paper/search?query=LLM&limit=5&fields=title,year,citationCount" \
  -H "Authorization: Bearer sk-user-your-key-here"

Billing

Billable endpoints consume credits. Prices depend on the current Open Platform configuration and request size. Batch endpoint billing may also change with the service. Check the price displayed in the Open Platform before submitting, and use the response headers to confirm the actual charge afterward.

For multiple papers, consider batch endpoints to reduce the number of requests. See the interactive API documentation for item limits and pricing.

Failures and retries

Refunds for failed tool requests follow the rules of the relevant endpoint. Other successful calls in a combined workflow may still incur charges. If the network disconnects, a missing response does not mean the service did not execute. Check usage records before retrying.

Read actual costs from the response

Billable endpoints provide the following response headers for reconciliation and budget control. The fields actually returned depend on the endpoint documentation:

Check your balance for free

GET /api/credits is free and can be used to check your budget before starting a task:

curl "https://ai4scholar.net/api/credits" \
  -H "Authorization: Bearer sk-user-your-key-here"

{
  "credit_contract_version": 2,
  "unit": "credits",
  "credits": {
    "permanent": 1000,
    "member_monthly_remaining": 0,
    "total_available": 980,
    "held": 20
  },
  "api_key": {
    "credit_limit": null,
    "credits_used": 21,
    "held_credits": 20,
    "credits_remaining": null
  },
  "membership": null
}

This is a shortened example of the unified credits API. The exact detail object is omitted, and the values are illustrative:

• permanent is the permanent credit balance; member_monthly_remaining retains compatibility information for legacy monthly membership benefits.
• total_available is the amount currently available after reservations; held is the number of credits temporarily reserved by running requests. Do not replace the available amount by simply adding the two balance fields.
• An api_key.credit_limit of null means that key has no spending cap. When a cap is set, also check the key's own credits_remaining.
• A membership value of null does not prevent you from using permanent credit packs. See Credits and plans for current purchase and billing rules.

Rate limits

Request limits are enforced according to the account, API key, and service configuration. If you receive 429, reduce concurrency, increase the retry interval, and check the current limits in the Open Platform. This guide does not hardcode plan limits.

Error codes