wifi-densepose/examples/data/framework/docs/API_CLIENTS_INVENTORY.md

RuVector Data Framework - API Clients Comprehensive Inventory

Overview

Complete analysis of 12 client modules providing access to 30+ data sources across 10 domains.

Total Clients Analyzed: 30 Total Public Methods: 150+ Domain Coverage: News, Social, Research, Economic, Patent, Space, Genomics, Physics, Medical, Knowledge Graph Data Format: All convert to SemanticVector or DataRecord with embeddings

---

1. api_clients.rs - News & Social Media

News API Client

Endpoint: https://newsapi.org/v2 Authentication: Required (API key) Rate Limit: 100ms delay (configurable)

Methods (4):

• new(api_key: String) - Initialize client
• search_articles(query, from_date, to_date, language) - Search news articles
• get_top_headlines(category, country) - Get top headlines by category/country
• get_sources(category, language, country) - List available news sources

Rate Limiting:

const DEFAULT_RATE_LIMIT_DELAY_MS: u64 = 100;
rate_limit_delay: Duration

Data Transformation:

NewsArticle -> SemanticVector {
    id: format!("NEWS:{}", hash(url)),
    embedding: embed_text(title + description + content),
    domain: Domain::News,
    metadata: {title, author, source, url, published_at, description}
}

Error Handling:

• Retry on TOO_MANY_REQUESTS (max 3 retries)
• Exponential backoff: RETRY_DELAY_MS * retries
• Network error wrapping via FrameworkError::Network

---

Reddit Client

Endpoint: https://oauth.reddit.com Authentication: Required (client_id, client_secret) Rate Limit: 1000ms delay (Reddit: 60 req/min)

Methods (5):

• new(client_id, client_secret) - OAuth authentication
• search_posts(query, subreddit, limit) - Search posts in subreddit
• get_hot_posts(subreddit, limit) - Get hot posts
• get_top_posts(subreddit, time_filter, limit) - Get top posts (hour/day/week/month/year/all)
• get_post_comments(post_id, limit) - Get post comments

Rate Limiting:

const REDDIT_RATE_LIMIT_MS: u64 = 1000; // 60 req/min

Data Transformation:

RedditPost -> SemanticVector {
    id: format!("REDDIT:{}", post_id),
    embedding: embed_text(title + selftext),
    domain: Domain::Social,
    metadata: {subreddit, author, score, num_comments, created_utc, url}
}

---

GitHub Client

Endpoint: https://api.github.com Authentication: Optional (higher rate limits with token) Rate Limit: 1000ms delay (5000/hour with token, 60/hour without)

Methods (4):

• new(token: Option<String>) - Initialize with optional token
• search_repositories(query, sort, limit) - Search repos
• get_repository_issues(owner, repo, state) - Get issues (open/closed/all)
• search_code(query, language, limit) - Search code

Rate Limiting:

const GITHUB_RATE_LIMIT_MS: u64 = 1000;
rate_limit_delay: Duration

---

HackerNews Client

Endpoint: https://hacker-news.firebaseio.com/v0 Authentication: Not required Rate Limit: 100ms delay

Methods (4):

• new() - Initialize client
• get_top_stories(limit) - Get top stories
• get_new_stories(limit) - Get newest stories
• get_best_stories(limit) - Get best stories

Data Transformation:

HnStory -> SemanticVector {
    id: format!("HN:{}", story_id),
    embedding: embed_text(title + text),
    domain: Domain::News,
    metadata: {title, url, score, descendants (comments), by (author)}
}

---

2. economic_clients.rs - Economic & Financial Data

World Bank Client

Endpoint: https://api.worldbank.org/v2 Authentication: Not required Rate Limit: 250ms delay

Methods (3):

• new() - Initialize client
• get_indicator_data(indicator, country, start_year, end_year) - Get economic indicators
• search_indicators(query) - Search available indicators

Common Indicators:

• NY.GDP.MKTP.CD - GDP (current US$)
• SP.POP.TOTL - Population
• NY.GDP.PCAP.CD - GDP per capita
• FP.CPI.TOTL.ZG - Inflation rate

Data Transformation:

WorldBankIndicator -> SemanticVector {
    id: format!("WB:{}:{}:{}", country, indicator, date),
    embedding: embed_text(indicator_name + country),
    domain: Domain::Economic,
    metadata: {indicator, country, value, date, country_name, indicator_name}
}

---

FRED Client (Federal Reserve Economic Data)

Endpoint: https://api.stlouisfed.org/fred Authentication: Required (API key from research.stlouisfed.org) Rate Limit: 200ms delay

Methods (3):

• new(api_key) - Initialize with FRED API key
• get_series(series_id, start_date, end_date) - Get time series data
• search_series(query) - Search available series

Popular Series:

• GDP - Gross Domestic Product
• UNRATE - Unemployment Rate
• CPIAUCSL - Consumer Price Index
• DFF - Federal Funds Rate

---

Alpha Vantage Client

Endpoint: https://www.alphavantage.co/query Authentication: Required (free tier: 5 req/min, 500/day) Rate Limit: 12000ms delay (5 req/min)

Methods (4):

• new(api_key) - Initialize client
• get_stock_price(symbol) - Real-time stock price
• get_time_series_daily(symbol, days) - Historical daily prices
• get_forex_rate(from_currency, to_currency) - FX rates

---

IMF Client (International Monetary Fund)

Endpoint: https://www.imf.org/external/datamapper/api/v1 Authentication: Not required Rate Limit: 500ms delay

Methods (2):

• new() - Initialize client
• get_indicator(indicator_code, countries) - Get IMF indicators

---

3. patent_clients.rs - Patent Data

USPTO Client (US Patent Office)

Endpoint: https://developer.uspto.gov/ibd-api/v1 Authentication: Not required Rate Limit: 500ms delay

Methods (3):

• new() - Initialize client
• search_patents(query, start_date, end_date) - Search patents
• get_patent(patent_number) - Get specific patent

---

EPO Client (European Patent Office)

Endpoint: https://ops.epo.org/3.2/rest-services Authentication: Required (OAuth2) Rate Limit: 1000ms delay

Methods (3):

• new(consumer_key, consumer_secret) - OAuth2 authentication
• search_patents(query) - Search European patents
• get_patent_details(patent_number) - Get patent details

---

Google Patents Client

Endpoint: https://patents.google.com Authentication: Not required Rate Limit: 1000ms delay (conservative)

Methods (2):

• new() - Initialize client
• search_patents(query, max_results) - Search patents

---

4. arxiv_client.rs - Research Papers

ArXiv Client

Endpoint: http://export.arxiv.org/api/query Authentication: Not required Rate Limit: 3000ms delay (max 1 req/3sec per ArXiv guidelines)

Methods (4):

• new() - Initialize client
• search(query, max_results) - Search papers by query
• search_by_category(category, max_results) - Search by category (cs.AI, physics.gen-ph, etc.)
• get_paper(arxiv_id) - Get specific paper by ID

Categories Supported:

• cs.AI - Artificial Intelligence
• cs.LG - Machine Learning
• physics.gen-ph - General Physics
• math.CO - Combinatorics
• q-bio.GN - Genomics

Data Transformation:

ArxivEntry -> SemanticVector {
    id: format!("ARXIV:{}", arxiv_id),
    embedding: embed_text(title + summary),
    domain: Domain::Research,
    metadata: {arxiv_id, title, summary, authors, published, updated, category, pdf_url}
}

---

5. semantic_scholar.rs - Academic Papers

Semantic Scholar Client

Endpoint: https://api.semanticscholar.org/graph/v1 Authentication: Optional (API key for higher limits) Rate Limit:

• Without key: 1000ms (100 req/5min)
• With key: 100ms (1000 req/5min)

Methods (6):

• new(api_key: Option<String>) - Initialize client
• search_papers(query, limit) - Search papers
• get_paper(paper_id) - Get paper by S2 ID or DOI
• get_paper_citations(paper_id, limit) - Get citing papers
• get_paper_references(paper_id, limit) - Get referenced papers
• search_authors(query, limit) - Search authors

Data Transformation:

S2Paper -> SemanticVector {
    id: format!("S2:{}", paper_id),
    embedding: embed_text(title + abstract),
    domain: Domain::Research,
    metadata: {
        paper_id, title, abstract, authors, year,
        citation_count, reference_count, fields_of_study,
        venue, doi, arxiv_id, pubmed_id
    }
}

---

6. biorxiv_client.rs - Biomedical Preprints

bioRxiv Client

Endpoint: https://api.biorxiv.org/details/biorxiv Authentication: Not required Rate Limit: 500ms delay

Methods (4):

• new() - Initialize client
• search_preprints(query, days_back) - Search preprints
• get_preprint(doi) - Get preprint by DOI
• get_recent(days, limit) - Get recent preprints

---

medRxiv Client

Endpoint: https://api.biorxiv.org/details/medrxiv Authentication: Not required Rate Limit: 500ms delay

Methods (4):

• Same as bioRxiv but for medical preprints

Data Transformation:

BiorxivPreprint -> SemanticVector {
    id: format!("BIORXIV:{}", doi),
    embedding: embed_text(title + abstract),
    domain: Domain::Research,
    metadata: {doi, title, authors, date, category, version, abstract}
}

---

7. crossref_client.rs - DOI Registry

CrossRef Client

Endpoint: https://api.crossref.org/works Authentication: Not required (polite pool with email recommended) Rate Limit: 200ms delay

Methods (5):

• new(mailto: Option<String>) - Initialize with optional email
• search_works(query, limit) - Search scholarly works
• get_work(doi) - Get work by DOI
• get_journal_articles(issn, limit) - Get articles from journal
• search_by_type(work_type, query, limit) - Search by type (journal-article, book-chapter, etc.)

Work Types:

• journal-article
• book-chapter
• proceedings-article
• posted-content
• dataset

---

8. space_clients.rs - Space & Astronomy

NASA APOD Client (Astronomy Picture of the Day)

Endpoint: https://api.nasa.gov/planetary/apod Authentication: API key (DEMO_KEY for testing) Rate Limit: 1000ms delay

Methods (3):

• new(api_key: Option<String>) - Use DEMO_KEY if none provided
• get_today() - Get today's APOD
• get_date(date) - Get APOD for specific date

---

SpaceX Launch Client

Endpoint: https://api.spacexdata.com/v4 Authentication: Not required Rate Limit: 500ms delay

Methods (4):

• new() - Initialize client
• get_latest_launch() - Get most recent launch
• get_upcoming_launches(limit) - Get upcoming launches
• get_past_launches(limit) - Get historical launches

---

SIMBAD Astronomical Database Client

Endpoint: https://simbad.cds.unistra.fr/simbad/sim-tap Authentication: Not required Rate Limit: 1000ms delay

Methods (3):

• new() - Initialize client
• search_objects(query) - Search astronomical objects
• query_region(ra, dec, radius) - Search by sky coordinates

---

9. genomics_clients.rs - Genomics & Proteomics

NCBI Gene Client

Endpoint: https://eutils.ncbi.nlm.nih.gov/entrez/eutils Authentication: Optional (API key for higher rate limits) Rate Limit:

• Without key: 334ms (~3 req/sec)
• With key: 100ms (10 req/sec)

Methods (4):

• new(api_key: Option<String>) - Initialize client
• search_genes(query, organism, max_results) - Search genes
• get_gene(gene_id) - Get gene details by ID
• get_gene_summary(gene_id) - Get gene summary

---

Ensembl Client

Endpoint: https://rest.ensembl.org Authentication: Not required Rate Limit: 200ms delay (15 req/sec limit)

Methods (5):

• new() - Initialize client
• search_genes(query, species) - Search genes in species
• get_sequence(gene_id) - Get gene sequence
• get_homology(gene_id) - Get homologous genes across species
• get_variants(gene_id) - Get genetic variants

---

UniProt Client

Endpoint: https://rest.uniprot.org Authentication: Not required Rate Limit: 200ms delay

Methods (4):

• new() - Initialize client
• search_proteins(query, limit) - Search proteins
• get_protein(accession) - Get protein by accession
• get_protein_features(accession) - Get protein features

---

PDB Client (Protein Data Bank)

Endpoint: https://search.rcsb.org/rcsbsearch/v2/query Authentication: Not required Rate Limit: 500ms delay

Methods (3):

• new() - Initialize client
• search_structures(query, limit) - Search protein structures
• get_structure(pdb_id) - Get structure by PDB ID

---

10. physics_clients.rs - Physics & Earth Science

USGS Earthquake Client

Endpoint: https://earthquake.usgs.gov/fdsnws/event/1 Authentication: Not required Rate Limit: 200ms delay (~5 req/sec)

Methods (5):

• new() - Initialize client
• get_recent(min_magnitude, days) - Recent earthquakes
• search_by_region(lat, lon, radius_km, days) - Regional search
• get_significant(days) - Significant earthquakes (mag ≥6.0 or sig ≥600)
• get_by_magnitude_range(min, max, days) - Magnitude range

Data Transformation:

UsgsEarthquake -> SemanticVector {
    id: format!("USGS:{}", earthquake_id),
    embedding: embed_text("Magnitude {mag} earthquake at {place}"),
    domain: Domain::Seismic,
    metadata: {
        magnitude, place, latitude, longitude, depth_km,
        tsunami, significance, status, alert
    }
}

---

CERN Open Data Client

Endpoint: https://opendata.cern.ch/api/records Authentication: Not required Rate Limit: 500ms delay

Methods (3):

• new() - Initialize client
• search_datasets(query) - Search LHC datasets
• get_dataset(recid) - Get dataset by record ID
• search_by_experiment(experiment) - Search by experiment (CMS, ATLAS, LHCb, ALICE)

Data Transformation:

CernRecord -> SemanticVector {
    id: format!("CERN:{}", recid),
    embedding: embed_text(title + description + experiment),
    domain: Domain::Physics,
    metadata: {
        recid, title, experiment, collision_energy,
        collision_type, data_type
    }
}

---

Argo Ocean Data Client

Endpoint: https://data-argo.ifremer.fr Authentication: Not required Rate Limit: 300ms delay (~3 req/sec)

Methods (4):

• new() - Initialize client
• get_recent_profiles(days) - Recent ocean profiles
• search_by_region(lat, lon, radius_km) - Regional ocean data
• get_temperature_profiles() - Temperature-focused profiles
• create_sample_profiles(count) - Generate sample data for testing

---

Materials Project Client

Endpoint: https://api.materialsproject.org Authentication: Required (API key from materialsproject.org) Rate Limit: 1000ms delay (1 req/sec for free tier)

Methods (3):

• new(api_key) - Initialize with API key
• search_materials(formula) - Search by chemical formula (Si, Fe2O3, LiFePO4)
• get_material(material_id) - Get material by MP ID (mp-149)
• search_by_property(property, min, max) - Search by property range (band_gap, density)

---

11. wiki_clients.rs - Knowledge Graphs

Wikipedia Client

Endpoint: https://{lang}.wikipedia.org/w/api.php Authentication: Not required Rate Limit: 100ms delay

Methods (4):

• new(language) - Initialize for language (en, de, fr, etc.)
• search(query, limit) - Search articles (max 500)
• get_article(title) - Get article by title
• get_categories(title) - Get article categories
• get_links(title) - Get outgoing links

Data Transformation:

WikiPage -> DataRecord {
    id: format!("wikipedia_{}_{}", language, pageid),
    source: "wikipedia",
    record_type: "article",
    embedding: embed_text(title + extract),
    relationships: [
        {target: category, rel_type: "in_category", weight: 1.0},
        {target: linked_page, rel_type: "links_to", weight: 0.5}
    ]
}

---

Wikidata Client

Endpoint: https://www.wikidata.org/w/api.php SPARQL Endpoint: https://query.wikidata.org/sparql Authentication: Not required Rate Limit: 100ms delay

Methods (7):

• new() - Initialize client
• search_entities(query) - Search Wikidata entities
• get_entity(qid) - Get entity by Q-identifier (Q42 = Douglas Adams)
• sparql_query(query) - Execute SPARQL query
• query_climate_entities() - Predefined climate change query
• query_pharmaceutical_companies() - Pharma companies query
• query_disease_outbreaks() - Disease outbreaks query

Predefined SPARQL Queries (5):

• CLIMATE_CHANGE - Climate change entities
• PHARMACEUTICAL_COMPANIES - Pharma companies with founding dates, employees
• DISEASE_OUTBREAKS - Epidemic events with locations, casualties
• RESEARCH_INSTITUTIONS - Research institutes by country
• NOBEL_LAUREATES - Nobel Prize winners by field and year

---

12. medical_clients.rs - Medical & Health Data

PubMed Client

Endpoint: https://eutils.ncbi.nlm.nih.gov/entrez/eutils Authentication: Optional (NCBI API key) Rate Limit:

• Without key: 334ms (~3 req/sec)
• With key: 100ms (10 req/sec)

Methods (4):

• new(api_key: Option<String>) - Initialize client
• search_articles(query, max_results) - Search medical literature
• search_pmids(query, max_results) - Get PMIDs only
• fetch_abstracts(pmids) - Fetch full abstracts (batches of 200)

Data Transformation:

PubmedArticle -> SemanticVector {
    id: format!("PMID:{}", pmid),
    embedding: embed_text(title + abstract),
    domain: Domain::Medical,
    metadata: {pmid, title, abstract, authors, publication_date},
    embedding_dimension: 384 // Higher for medical text
}

---

ClinicalTrials.gov Client

Endpoint: https://clinicaltrials.gov/api/v2 Authentication: Not required Rate Limit: 100ms delay

Methods (2):

• new() - Initialize client
• search_trials(condition, status) - Search trials by condition and status
  • Status: RECRUITING, COMPLETED, ACTIVE_NOT_RECRUITING, etc.

Data Transformation:

ClinicalStudy -> SemanticVector {
    id: format!("NCT:{}", nct_id),
    embedding: embed_text(title + summary + conditions),
    domain: Domain::Medical,
    metadata: {nct_id, title, summary, conditions, status}
}

---

FDA OpenFDA Client

Endpoint: https://api.fda.gov Authentication: Not required Rate Limit: 250ms delay (~4 req/sec)

Methods (3):

• new() - Initialize client
• search_drug_events(drug_name) - Search adverse drug events
• search_recalls(reason) - Search device recalls

Data Transformation:

FdaDrugEvent -> SemanticVector {
    id: format!("FDA_EVENT:{}", safety_report_id),
    embedding: embed_text("Drug: {drugs} Reactions: {reactions}"),
    domain: Domain::Medical,
    metadata: {report_id, drugs, reactions, serious}
}

FdaRecall -> SemanticVector {
    id: format!("FDA_RECALL:{}", recall_number),
    embedding: embed_text("Product: {product} Reason: {reason}"),
    domain: Domain::Medical,
    metadata: {recall_number, reason, product, classification}
}

---

Common Patterns Across All Clients

1. Error Handling Pattern

async fn fetch_with_retry(&self, url: &str) -> Result<reqwest::Response> {
    let mut retries = 0;
    loop {
        match self.client.get(url).send().await {
            Ok(response) => {
                if response.status() == StatusCode::TOO_MANY_REQUESTS
                   && retries < MAX_RETRIES {
                    retries += 1;
                    sleep(Duration::from_millis(RETRY_DELAY_MS * retries as u64)).await;
                    continue;
                }
                return Ok(response);
            }
            Err(_) if retries < MAX_RETRIES => {
                retries += 1;
                sleep(Duration::from_millis(RETRY_DELAY_MS * retries as u64)).await;
            }
            Err(e) => return Err(FrameworkError::Network(e)),
        }
    }
}

Constants:

• MAX_RETRIES: u32 = 3
• RETRY_DELAY_MS: u64 = 1000
• Exponential backoff: delay * retries

---

2. Rate Limiting Pattern

// Before each API call
sleep(self.rate_limit_delay).await;
let response = self.fetch_with_retry(&url).await?;

Rate Limit Table:

Client	Delay (ms)	Req/Sec	Notes
News API	100	~10	Configurable
Reddit	1000	1	60 req/min limit
GitHub	1000	1	5000/hr with token
HackerNews	100	~10	No auth required
World Bank	250	4	No auth required
FRED	200	5	API key required
Alpha Vantage	12000	0.08	5 req/min limit
IMF	500	2	No auth required
USPTO	500	2	No auth required
EPO	1000	1	OAuth2 required
Google Patents	1000	1	Conservative
ArXiv	3000	0.33	1 req/3sec guideline
Semantic Scholar (no key)	1000	1	100 req/5min
Semantic Scholar (with key)	100	10	1000 req/5min
bioRxiv/medRxiv	500	2	No auth required
CrossRef	200	5	Polite pool with email
NASA APOD	1000	1	DEMO_KEY available
SpaceX	500	2	No auth required
SIMBAD	1000	1	TAP service
NCBI Gene (no key)	334	3	NCBI guidelines
NCBI Gene (with key)	100	10	API key required
Ensembl	200	5	15 req/sec limit
UniProt	200	5	No auth required
PDB	500	2	No auth required
USGS	200	5	Real-time seismic
CERN	500	2	Open data portal
Argo	300	3	Ocean float data
Materials Project	1000	1	1 req/sec free tier
Wikipedia	100	~10	No auth required
Wikidata	100	~10	SPARQL available
PubMed (no key)	334	3	NCBI guidelines
PubMed (with key)	100	10	API key required
ClinicalTrials	100	~10	No auth required
FDA OpenFDA	250	4	No auth required

---

3. Embedding Pattern

// SimpleEmbedder - deterministic hash-based embeddings
embedder: Arc<SimpleEmbedder> = Arc::new(SimpleEmbedder::new(dimension));

// Dimensions by domain:
// - 256: Most clients (news, social, research)
// - 384: Medical/scientific (PubMed, ClinicalTrials, FDA)
// - Configurable per client based on text complexity

---

4. Metadata Pattern

let mut metadata = HashMap::new();
metadata.insert("source".to_string(), "client_name".to_string());
metadata.insert("id".to_string(), record_id);
// Domain-specific fields

Common Metadata Fields:

• source - Client identifier
• title - Record title
• url - Source URL
• timestamp - Publication/update date
• Domain-specific fields (authors, categories, scores, etc.)

---

Summary Statistics

By Domain Coverage

News & Social: 4 clients (News API, Reddit, GitHub, HackerNews)
Economic: 4 clients (World Bank, FRED, Alpha Vantage, IMF)
Patents: 3 clients (USPTO, EPO, Google Patents)
Research: 4 clients (ArXiv, Semantic Scholar, bioRxiv, CrossRef)
Space: 3 clients (NASA APOD, SpaceX, SIMBAD)
Genomics: 4 clients (NCBI Gene, Ensembl, UniProt, PDB)
Physics: 4 clients (USGS, CERN, Argo, Materials Project)
Knowledge: 2 clients (Wikipedia, Wikidata)
Medical: 3 clients (PubMed, ClinicalTrials, FDA)

By Authentication Requirements

No Auth Required: 17 clients (57%)
Optional Auth: 5 clients (17%) - improved rate limits
Required Auth: 8 clients (26%)

By Method Count

Total Public Methods: 150+
Average per client: ~5 methods
Range: 2-7 methods per client

By Rate Limit Strictness

Very Strict (>1000ms): 2 clients - ArXiv (3000ms), Alpha Vantage (12000ms)
Strict (500-1000ms): 11 clients
Moderate (200-500ms): 11 clients
Permissive (<200ms): 6 clients

By Embedding Dimensions

256 dimensions: 26 clients (87%)
384 dimensions: 4 clients (13%) - medical/scientific domains

---

Data Flow Architecture

API Source → Client → Response Parser → SemanticVector/DataRecord
                                              ↓
                                       Embedding (SimpleEmbedder)
                                              ↓
                                       Domain Classification
                                              ↓
                                       Metadata Extraction
                                              ↓
                                       RuVector Storage

---

Usage Recommendations

1. Rate Limit Compliance

• Always use provided rate limit delays
• Consider API key registration for higher limits
• Batch requests when possible (e.g., PubMed: 200 PMIDs/request)

2. Error Handling

• All clients implement retry logic with exponential backoff
• Handle FrameworkError::Network for connectivity issues
• Check for empty results (some APIs return 404 for no matches)

3. Authentication

• Store API keys in environment variables
• Use optional auth when available for better rate limits
• OAuth2 clients (Reddit, EPO) require credential management

4. Performance Optimization

• Use parallel requests for independent queries
• Leverage batch endpoints (PubMed abstracts, etc.)
• Cache results when appropriate
• Consider semantic search with embeddings vs. full-text search

5. Domain-Specific Considerations

• Medical: Higher embedding dimensions (384) for richer semantics
• Research: Check multiple sources (ArXiv + Semantic Scholar + CrossRef)
• Economic: Time-series data requires date range management
• Genomics: Species-specific searches (Ensembl supports 100+ species)
• Physics: Geographic searches use Haversine distance calculations

---

Integration Example

use ruvector_data_framework::*;

#[tokio::main]
async fn main() -> Result<()> {
    // Initialize multiple clients
    let arxiv = ArxivClient::new()?;
    let s2 = SemanticScholarClient::new(Some("API_KEY".to_string()))?;
    let pubmed = PubMedClient::new(Some("NCBI_KEY".to_string()))?;

    // Parallel search across domains
    let query = "machine learning healthcare";

    let (arxiv_results, s2_results, pubmed_results) = tokio::join!(
        arxiv.search(query, 50),
        s2.search_papers(query, 50),
        pubmed.search_articles(query, 50)
    );

    // Combine vectors
    let mut all_vectors = Vec::new();
    all_vectors.extend(arxiv_results?);
    all_vectors.extend(s2_results?);
    all_vectors.extend(pubmed_results?);

    // Store in RuVector for semantic search
    // ... vector storage code ...

    Ok(())
}

---

Future Enhancements

1. Dynamic Rate Limiting: Adjust based on response headers
2. Circuit Breakers: Fail-fast on repeated errors
3. Response Caching: Redis/disk cache for repeated queries
4. Streaming APIs: Support for SSE/WebSocket endpoints
5. Advanced Embeddings: Integration with transformer models
6. Relationship Graphs: Enhanced Wikipedia/Wikidata graph traversal
7. Multi-language Support: Expand beyond English for international sources
8. Specialized Domains: Climate, energy, agriculture data sources

---

Last Updated: 2026-01-04 Total Clients: 30 Total Methods: 150+ API Coverage: 10 domains across research, economic, medical, and scientific data