rust.md

Rust guide

README | Python | Rust | Go

libfmp is the async, typed Rust core. Endpoint descriptors, typed queries, response models, and Client methods cover every documented oracle entry: 271 methods across 30 domains. Start with installation, then the API reference on docs.rs.

Fetch a quote

use std::env;

use libfmp::{Client, config::Authentication, types::Ticker};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = Client::builder()
        .authentication(Authentication::fmp_header(env::var("FMP_API_KEY")?))
        .build()?;
    let rows = client.quote_short(Ticker::new("AAPL")?).await?;
    println!("{rows:#?}");
    Ok(())
}

The Rust builder never reads the environment on its own. When the key lives in FMP_API_KEY, Authentication::fmp_header_from_env() returns the same header authentication as Option<Authentication> (None when the variable is unset, empty, or whitespace-only), so the env::var line above is the explicit form.

The client is async: every endpoint method returns a future, so it runs under an async runtime such as tokio. quote_short, for example, preserves FMP's bare-array response as Vec<QuoteShort>, including empty and multi-row responses.

Custom routers and proxies

Endpoint code is independent of transport configuration. The builder accepts a custom base URL and path prefix, no authentication, FMP header or query authentication, bearer authentication, custom secret headers or query parameters, and arbitrary default headers. Redirect following is either disabled or restricted to the same origin, so credentials are never forwarded across origins. The crate README shows the full proxy builder in Custom router or proxy.

Reference

• API reference on docs.rs.
• Crate README: the text packaged with the crate.
• Core source: client, configuration, transport, and one module per endpoint domain.
• Tests and the recorded wire fixtures they decode.