reqwest & sqlx

Q: sqlx with SQLite?

Enable sqlite feature. Great for tests and edge deployments.

Q: Timeouts?

Set Client::builder().timeout(...) and sqlx acquire_timeout on pool options.

Q: Connection string secrets?

Load DATABASE_URL from env at runtime, never commit credentials.

reqwest is the ergonomic async HTTP client. sqlx is an async, compile-time-checked SQL toolkit. Together they cover most service IO boundaries.

Recipe

[dependencies]
tokio = { version = "1", features = ["full"] }
reqwest = { version = "0.12", features = ["json", "rustls-tls"] }
sqlx = { version = "0.8", features = ["runtime-tokio-rustls", "postgres", "macros"] }
serde = { version = "1.0", features = ["derive"] }

use serde::Deserialize;
 
#[derive(Deserialize)]
struct Health { status: String }
 
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let health: Health = reqwest::get("https://httpbin.org/status/200")
        .await?
        .error_for_status()?
        .json()
        .await
        .unwrap_or(Health { status: "ok".into() });
    println!("{}", health.status);
    Ok(())
}

When to reach for this:

Microservices calling other HTTP APIs
Postgres/MySQL/SQLite with async pools
Axum handlers needing DB + outbound HTTP

Working Example

use sqlx::PgPool;
 
async fn count_users(pool: &PgPool) -> sqlx::Result<i64> {
    let row: (i64,) = sqlx::query_as("SELECT COUNT(*) FROM users")
        .fetch_one(pool)
        .await?;
    Ok(row.0)
}

async fn notify_webhook(url: &str, body: &str) -> reqwest::Result<()> {
    reqwest::Client::new()
        .post(url)
        .header("content-type", "application/json")
        .body(body.to_string())
        .send()
        .await?
        .error_for_status()?;
    Ok(())
}

What this demonstrates:

query_as maps rows to tuples or structs
error_for_status turns 4xx/5xx into errors
Both integrate with Tokio

Deep Dive

sqlx Compile-Time Check

// Requires DATABASE_URL at build for query! macro
let user = sqlx::query_as!(User, "SELECT id, email FROM users WHERE id = $1", id)
    .fetch_one(pool)
    .await?;

Use offline mode (sqlx prepare) in CI when the DB is not available at compile time.

Cross-Links

Gotchas

Default TLS features - prefer rustls-tls for reproducible builds. Fix: disable default OpenSSL unless required.
Connection pool per request - exhausts DB. Fix: one PgPool in app state.
reqwest Client per call - loses keep-alive. Fix: reuse Client from OnceLock or Axum state.
sqlx without migrations - schema drift. Fix: sqlx migrate in deploy pipeline.
Large JSON bodies - memory spikes. Fix: streaming with bytes_stream.

Alternatives

Alternative	Use When	Don't Use When
`hyper` directly	Custom HTTP	Typical REST clients
`sea-orm`	ORM layer on sqlx	Raw SQL preference
`tokio-postgres`	Lower-level control	Want compile-time queries

FAQs

reqwest blocking client?

Exists for sync CLIs. Async client is default for Tokio services.

sqlx with SQLite?

Enable sqlite feature. Great for tests and edge deployments.

Timeouts?

Set Client::builder().timeout(...) and sqlx acquire_timeout on pool options.

Connection string secrets?

Load DATABASE_URL from env at runtime, never commit credentials.

Stack versions: This page was written for Rust 1.97.0 (edition 2024), Tokio 1.x, Axum 0.8, serde 1.0, sqlx 0.8, clap 4, and Polars 0.46+.

Recipe

[dependencies]
tokio = { version = "1", features = ["full"] }
reqwest = { version = "0.12", features = ["json", "rustls-tls"] }
sqlx = { version = "0.8", features = ["runtime-tokio-rustls", "postgres", "macros"] }
serde = { version = "1.0", features = ["derive"] }

use serde::Deserialize;
 
#[derive(Deserialize)]
struct Health { status: String }
 
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let health: Health = reqwest::get("https://httpbin.org/status/200")
        .await?
        .error_for_status()?
        .json()
        .await
        .unwrap_or(Health { status: "ok".into() });
    println!("{}", health.status);
    Ok(())
}

When to reach for this:

Microservices calling other HTTP APIs
Postgres/MySQL/SQLite with async pools
Axum handlers needing DB + outbound HTTP

Working Example

use sqlx::PgPool;
 
async fn count_users(pool: &PgPool) -> sqlx::Result<i64> {
    let row: (i64,) = sqlx::query_as("SELECT COUNT(*) FROM users")
        .fetch_one(pool)
        .await?;
    Ok(row.0)
}

async fn notify_webhook(url: &str, body: &str) -> reqwest::Result<()> {
    reqwest::Client::new()
        .post(url)
        .header("content-type", "application/json")
        .body(body.to_string())
        .send()
        .await?
        .error_for_status()?;
    Ok(())
}

What this demonstrates:

query_as maps rows to tuples or structs
error_for_status turns 4xx/5xx into errors
Both integrate with Tokio

Deep Dive

sqlx Compile-Time Check

// Requires DATABASE_URL at build for query! macro
let user = sqlx::query_as!(User, "SELECT id, email FROM users WHERE id = $1", id)
    .fetch_one(pool)
    .await?;

Use offline mode (sqlx prepare) in CI when the DB is not available at compile time.

Cross-Links

Gotchas

Default TLS features - prefer rustls-tls for reproducible builds. Fix: disable default OpenSSL unless required.
Connection pool per request - exhausts DB. Fix: one PgPool in app state.
reqwest Client per call - loses keep-alive. Fix: reuse Client from OnceLock or Axum state.
sqlx without migrations - schema drift. Fix: sqlx migrate in deploy pipeline.
Large JSON bodies - memory spikes. Fix: streaming with bytes_stream.

Alternatives

Alternative	Use When	Don't Use When
`hyper` directly	Custom HTTP	Typical REST clients
`sea-orm`	ORM layer on sqlx	Raw SQL preference
`tokio-postgres`	Lower-level control	Want compile-time queries

FAQs

reqwest blocking client?

Exists for sync CLIs. Async client is default for Tokio services.

sqlx with SQLite?

Enable sqlite feature. Great for tests and edge deployments.

Timeouts?

Set Client::builder().timeout(...) and sqlx acquire_timeout on pool options.

Connection string secrets?

Load DATABASE_URL from env at runtime, never commit credentials.

Stack versions: This page was written for Rust 1.97.0 (edition 2024), Tokio 1.x, Axum 0.8, serde 1.0, sqlx 0.8, clap 4, and Polars 0.46+.

reqwest & sqlx

Buscar en la documentación

reqwest & sqlx