hal-archive-api

name	hal-archive-api
description	Access French and European research via the HAL open archive API
metadata	{"openclaw":{"emoji":"🇫🇷","category":"literature","subcategory":"fulltext","keywords":["HAL","French research","open archive","CNRS","European research","institutional repository"],"source":"https://api.archives-ouvertes.fr/"}}

HAL Open Archive API

Overview

HAL (Hyper Articles en Ligne) is France's national open archive for scholarly deposits. Managed by CNRS, it hosts 4M+ full-text documents from French research institutions and international collaborators. The API provides Solr-based search with full metadata, PDF links, and OAI-PMH harvesting. Free, no authentication required.

API Endpoints

Search API

# Keyword search
curl "https://api.archives-ouvertes.fr/search/?q=machine+learning&rows=20&wt=json"

# Search specific fields
curl "https://api.archives-ouvertes.fr/search/?q=title_s:\"deep learning\"&wt=json"

# Filter by document type
curl "https://api.archives-ouvertes.fr/search/?q=neural+networks&\
fq=docType_s:ART&rows=20&wt=json"

# Filter by year and language
curl "https://api.archives-ouvertes.fr/search/?q=climate+change&\
fq=producedDateY_i:[2023 TO 2026]&fq=language_s:en&wt=json"

# Filter by institution
curl "https://api.archives-ouvertes.fr/search/?q=robotics&\
fq=structId_i:441569&wt=json"

# Return specific fields
curl "https://api.archives-ouvertes.fr/search/?q=CRISPR&\
fl=halId_s,title_s,authFullName_s,producedDateY_i,uri_s,files_s&wt=json"

Search Fields

Field	Description	Example
title_s	Title	title_s:"attention mechanism"
authFullName_s	Author name	authFullName_s:"Yann LeCun"
abstract_s	Abstract	abstract_s:transformer
keyword_s	Keywords	keyword_s:"natural language"
producedDateY_i	Year	producedDateY_i:2024
docType_s	Document type	docType_s:ART
language_s	Language	language_s:en
domain_s	Domain/subject	domain_s:info.info-ai
journalTitle_s	Journal name	journalTitle_s:"Nature"
structId_i	Institution ID	Lab/university ID

Document Types

Code	Type
ART	Journal article
COMM	Conference paper
THESE	PhD thesis
HDR	Habilitation thesis
REPORT	Report
COUV	Book chapter
OUV	Book
POSTER	Poster
UNDEFINED	Preprint/other

Query Parameters

Parameter	Description
q	Solr query
fq	Filter query
fl	Fields to return
rows	Results per page (max 10000)
start	Pagination offset
sort	Sort order (e.g., producedDateY_i desc)
wt	Format: json, xml, csv

Response Structure

{
  "response": {
    "numFound": 12500,
    "start": 0,
    "docs": [
      {
        "halId_s": "hal-01234567",
        "title_s": ["Deep Learning for Climate Modeling"],
        "authFullName_s": ["Marie Dupont", "Jean Martin"],
        "producedDateY_i": 2024,
        "docType_s": "ART",
        "journalTitle_s": "Environmental Modelling",
        "uri_s": "https://hal.science/hal-01234567",
        "files_s": ["https://hal.science/hal-01234567/document"],
          
         
         
      
    
  

Python Usage

import requests

BASE_URL = "https://api.archives-ouvertes.fr/search/"


def search_hal(query: str, rows: int = 20,
               doc_type: str = None, from_year: int = None,
               language: str = None) -> list:
    """Search HAL open archive."""
    params = {
        "q": query,
        "wt": "json",
        "rows": rows,
        "fl": "halId_s,title_s,authFullName_s,producedDateY_i,"
              "uri_s,files_s,docType_s,journalTitle_s,abstract_s",
        "sort": "producedDateY_i desc",
    }

    fq = []
    if doc_type:
        fq.append(f"docType_s:{doc_type}")
    if from_year:
        fq.append(f"producedDateY_i:[{from_year} TO 2030]")
    if language:
        fq.append(f"language_s:{language}")
    if fq:
        params["fq"] = fq

    resp = requests.get(BASE_URL, params=params)
    resp.raise_for_status()
    data = resp.json()

    results = []
    for doc in data.get("response", {}).get("docs", []):
        title = doc.get("title_s", [""])[0] if isinstance(
            doc.get("title_s"), )  doc.get(, )
        results.append({
            : doc.get(),
            : title,
            : doc.get(, []),
            : doc.get(),
            : doc.get(),
            : doc.get(),
            : doc.get(),
            : doc.get(, [])[],
        })
     results


 () -> :
    
     search_hal(topic, rows=, doc_type=,
                      from_year=from_year)


 () -> :
    
    params = {
        : ,
        : [,
               ],
        : ,
        : ,
        : ,
        : ,
    }
    resp = requests.get(BASE_URL, params=params)
    resp.raise_for_status()
     resp.json().get(, {}).get(, [])



papers = search_hal(, from_year=)
 p  papers:
    pdf =   p[]  
    ()


theses = search_theses()
 t  theses:
    ()

HAL Domains

Code	Domain
info	Computer Science
math	Mathematics
phys	Physics
sde	Environmental Sciences
sdv	Life Sciences
shs	Social Sciences & Humanities
chim	Chemistry
spi	Engineering Sciences

References

• HAL Open Archive
• HAL API Documentation
• HAL Search Guide