xecute

xecute is a small dependency-injection runtime and macro facade for Axum applications. It provides typed providers, application/request scopes, module metadata, and startup validation. It is intentionally independent of any larger framework.

use xecute::{Container, Provider, InjectError};

struct Clock;
impl Provider for Clock {
    fn provide(_: &Container) -> Result<Self, InjectError> { Ok(Self) }
}

let container = Container::builder().injectable::<Clock>().build()?;
let clock = container.resolve::<Clock>()?;
# Ok::<(), xecute::InjectError>(())

It re-exports #[injectable], #[module], and the routing macros, so applications need only this one dependency.

Controller methods and validated payloads

Import xecute::prelude::*. Annotate a controller struct with #[controller("/v1/auth")] and #[derive(Injectable)], then put #[routes] on its implementation. HTTP handlers can take &self, #[body] request: Dto, and #[query] request: Dto. DTOs derive serde::Deserialize, validator::Validate, and schemars::JsonSchema. The generated adapters decode and validate before calling the handler. Invalid values return 422; submitted values are omitted from public validation errors. JSON syntax/content-type errors retain their HTTP status.

#[api(summary = "...", tag = "...", operation_id = "...")], #[body(json = RequestDto)], and #[resp(200, "Description", json = ReplyDto)] populate Controller::api_operations(). Pass these operations to xecute::openapi_document to build OpenAPI 3.1 with DTO/response schemas. Generated CLI applications register this document with their default Swagger UI.

Injectable repositories

Repositories can derive Injectable like controllers. Normal dependency fields, such as database: Arc<Database>, are resolved from the container. Mark local state with #[inject(default)] to initialize it using Default without treating it as a dependency. Register the repository in the module’s providers list; the default singleton scope shares one instance across injected services.

Middleware

Middleware functions accept Request and Next from xecute::middleware and return any IntoResponse value. Call next.run(request).await to continue; return a response directly to stop the pipeline. Register functions in request execution order; response processing unwinds in reverse.

use xecute::prelude::*;
use xecute::middleware::{Request, Next, Response};

async fn auth(request: Request, next: Next) -> Response {
    // Authenticate and insert identity into request.extensions_mut() here.
    next.run(request).await
}

#[controller("/users")]
#[middleware(auth)]
#[derive(Injectable)]
struct UserController {}

#[routes]
impl UserController {
    #[get("")]
    #[middleware(audit)]
    async fn list(&self) -> &'static str { "users" }
}

// Global middleware; closures can capture Arc-backed application dependencies.
let app = Application::new(UserController::router(controller))
    .use_middleware(request_context)
    .use_middleware(logging)
    .into_router();

Place controller #[middleware(...)] below #[controller(...)] on the struct, or below #[routes] on its impl. Route middleware belongs on a handler inside that impl. Multiple functions and repeated middleware attributes preserve their written order. Execution is app → controller struct → controller impl → route → extractors/validation → handler. Controller middleware applies only to matched controller routes; route middleware applies only to its HTTP method. App middleware wraps existing routes and fallback responses. Add all routes before building the application pipeline.

These are HTTP middleware; command/query handler pipelines are separate.

Typed configuration

These APIs are available with CLI 0.1.12, runtime 0.1.7, and macros 0.1.6. Update the CLI before generating a new project. Existing applications require corresponding dependency and source changes; updating the CLI does not rewrite them.

The common configuration boundary separates ConfigFile for ordinary settings from Env for secrets. Both report value-redacted validation errors. TOML parsing preserves native types: false is a boolean, while "false" is an invalid type for a boolean setting. get_or defaults only absent keys; supplied bad values remain errors. range enforces numeric bounds; required rejects missing keys. Generated configuration rejects unknown keys so typos cannot silently disable policies.

use xecute::config::{ConfigError, ConfigFile, Env, SecretString};

struct DatabaseConfig {
    url: SecretString,
    pool_size: u64,
}
impl DatabaseConfig {
    fn load(file: &ConfigFile) -> Result<Self, ConfigError> {
        Ok(Self {
            url: Env::process().secret("DATABASE_URL")?,
            pool_size: file.range("database.pool_size", 10, 1, 100)?,
        })
    }
}

Add database.pool_size to the generated allowed-key schema when introducing this custom setting. Initialize custom configuration before binding the listener. SecretString redacts Debug output and requires .expose() for SDK/client access; it does not promise memory zeroization. .env and TOML parse errors omit source contents. Tests can use ConfigFile::parse(source) and map-backed Env::new without changing process variables. Configuration is a startup snapshot.

Exception handling and domain mappings

Handlers and services can return typed domain errors. Map expected failures explicitly using From<DomainError> for HttpError; controllers returning Result<T, HttpError> can then use ?.

use xecute::{HttpError, HttpStatus};

struct EmailTaken;
impl From<EmailTaken> for HttpError {
    fn from(_: EmailTaken) -> Self {
        HttpError::public(
            HttpStatus::CONFLICT,
            "email_taken",
            "Email is already registered",
        )
    }
}

The response contains error.code, error.message, and a server-generated error.request_id matching X-Request-Id. Custom mappings survive generated response normalization. Public custom messages and codes are static API text; never include user input or secrets. Codes accept lowercase ASCII letters, digits, and underscores, up to 64 characters. Invalid codes use default details. All 5xx errors use safe default messages even if custom text is supplied. Invalid success statuses passed to HttpError::new become 500. Log an underlying failure explicitly before mapping it; the framework does not serialize error Display text.

HttpError produces a JSON envelope on its own, with an empty request ID when there is no request boundary. Generated applications already normalize errors, preserve protocol/CORS/retry headers, discard stale representation headers, and attach IDs. For a plain Axum router, install xecute::exceptions::exception_boundary(router) once after assembling routes. This helper normalizes error responses; generated servers also have their existing panic-catching and deadline middleware. A panic in an independent background task is outside the HTTP boundary.

Provider lifecycles and HTTP requests

use std::sync::Arc;
use xecute::{Injectable, controller, routes};

#[derive(Injectable)]
#[scope("request")]
struct RequestContext {
    #[inject(default)]
    state: std::sync::Mutex<Vec<String>>,
}

#[controller("/example-scope")]
#[derive(Injectable)]
#[scope("request")]
struct ExampleController {
    context: Arc<RequestContext>,
}

#[routes]
impl ExampleController {
    #[get("")]
    async fn get(&self) -> &'static str {
        let _ = &self.context;
        "request scope is active"
    }
}

Register both types in a module's providers. Generated AppModule uses Controller::scoped_router(container.clone()), creating a request context before controller middleware and extractors. Nested factories resolve against that same context. Use a named parameter context: xecute::Inject<RequestContext> in a controller method, or Inject<T> in a plain Axum handler, to resolve explicitly. Plain routers need xecute::with_container(router, Arc<Container>). To resolve providers in app-level middleware, wrap the fully assembled middleware pipeline with with_container as well. Matching nested boundaries reuse the same request cache; mixing different container registries in one boundary returns a safe 500 instead of resolving from the wrong application. Controller::router(Arc<Controller>) remains available for explicitly supplied controller instances; it cannot recreate their captured dependencies per request.

Use container.request() for jobs or tests requiring an explicit scope. Its clones share a request cache; a second call creates an independent cache. Request cache ownership is released at completion/cancellation, but any Arc retained by application code keeps its value alive. RequestContainer<'a> remains a compatibility alias for the owned RequestScope.

Startup rejects missing required registrations, duplicate providers/modules, cycles, private module dependencies, and singleton-to-request dependencies even through transient providers. Optional providers may be absent, but failures constructing a registered optional provider propagate. Factories must declare all dependencies; undeclared resolutions fail instead of risking recursive cache deadlocks. Custom definitions can mark a declared dependency optional with .optional_dependency::<T>().

Concurrent resolutions initialize each singleton/request provider once. Factory errors are cached for that scope; recover external connectivity inside a shared client instead of expecting factory retries. container.initialize() eagerly constructs singletons and is called before generated applications listen. Factories are synchronous: initialize asynchronous SDK/database clients at startup and register their handles as values. A transient injected into a singleton is created when that singleton is built, then retained by it.

Testing modules and HTTP assertions

Enable the runtime's optional test helpers only for development:

[dev-dependencies]
xecute = { version = "0.1.7", features = ["testing"] }

Generated manifests already include this entry. TestingModule compiles isolated containers, applies overrides before initialization, and validates the final dependency graph. Unknown or repeated overrides are errors, preventing a silently unused mock. Values replace the same registered Rust type; for trait-based mocks, use a concrete adapter containing Arc<dyn YourTrait> and replace that adapter. Production containers remain unchanged.

use std::sync::Arc;
use xecute::testing::{TestApp, TestingModule};

let mut module = TestingModule::new();
for definition in crate::app_module::AppModule::definitions() {
    module = module.module(definition);
}
// Example: module = module.override_value(DatabaseGateway(Arc::new(FakeDatabase)));
let container = Arc::new(module.compile()?);
let routes = crate::app_module::AppModule::router_with_container(container)?;
let app = TestApp::new(crate::server::router(routes, &crate::configs::Config::default()));

let response = app.post("/example")
    .json(&serde_json::json!({"name": "Example"}))
    .send().await?
    .assert_status(axum::http::StatusCode::CREATED);
let body: serde_json::Value = response.json()?;

Run these async helpers inside a Tokio runtime, such as #[tokio::test]. The client runs the actual Router and middleware without a socket. It supports arbitrary HTTP methods through .request, common method helpers, raw bodies, headers, JSON payloads, and .peer(SocketAddr) for limiter tests. Loopback peer information is supplied by default. Responses expose status, headers, bounded bytes, typed JSON, and chainable .assert_status/.assert_json methods. Invalid requests return test errors rather than panicking. Request and body collection have a five-second timeout and a 1 MiB response limit; adjust with TestApp::timeout and response_limit. This tests HTTP behavior in-process; network/TLS/deployment behavior still belongs in deployment smoke tests.

The generated src/tests/application.rs demonstrates isolated container startup and safe mapped errors. Resource tests demonstrate JSON validation and storage through the same test client. The runtime test suite also covers trait adapters, mock isolation, concurrent initialization, nested request scopes, and cleanup.

Multipart file uploads

Generated projects include src/modules/uploads/ with a controller and async startup module. Enable private writes explicitly in AppConfig.toml:

[uploads]
enabled = true
storage = "local"
directory = "storage/uploads"
max_files = 4
max_file_bytes = 524288
max_total_bytes = 524288
allowed_types = ["image/png", "image/jpeg", "application/pdf"]

The endpoint accepts repeated file parts:

curl -F 'file=@report.pdf;type=application/pdf' http://127.0.0.1:3000/uploads
curl -F 'file=@photo.png;type=image/png' -F 'file=@report.pdf;type=application/pdf' \
  http://127.0.0.1:3000/v1/uploads

A successful request returns 201 with an array of metadata containing key, original_name, content_type, size, and sha256. Generated UUID keys never use client filenames. Local objects and staging files stay outside public/; there is no public download route. Persist returned metadata in your own database and implement authorized retrieval/deletion according to your application rules. Attach authentication/permissions using the existing controller/route middleware before enabling upload writes in a deployed application.

The runtime streams each part to a temporary file and keeps only an 8 KiB sniff sample plus hashing state in memory. It checks actual per-file and aggregate bytes, file count, nonempty content, safe display filenames, and an exact MIME allowlist. Declared MIME must match an infer-recognized file signature; unknown formats and mismatches are rejected. Signature recognition is not a full decoder, malware scan, or content moderation system. Add those checks before publishing files when your application needs them. Text form fields are not part of this example contract; only repeated file fields are accepted.

server.body_limit_bytes also bounds multipart framing and headers. When uploads are enabled, startup requires it to cover uploads.max_total_bytes + 65536 bytes. To accept larger files, increase both limits explicitly. HTTP deadlines and global rate/concurrency policies still apply. The low-level UploadService expects its caller to apply an HTTP body limit as well; payload limits alone do not bound multipart headers or framing.

All files validate before any storage commit. Invalid batches remove staging files without writing final objects. Local storage publishes complete files atomically without replacing an existing key. Handled storage failures trigger best-effort deletion of previously committed batch objects. A process crash, cancelled request, or uncertain S3 response can leave staging/committed objects; use application reconciliation, disk quotas, and retention/cleanup appropriate to your deployment. Stored objects do not expire automatically. Keep upload storage and staging directories private and unavailable for untrusted filesystem writes.

S3 storage

S3 is an optional Cargo feature; local uploads do not compile the AWS SDK. Ordinary backend settings stay in AppConfig.toml:

[uploads]
enabled = true
storage = "s3"
directory = "storage/uploads" # private streaming staging directory
max_files = 4
max_file_bytes = 524288
max_total_bytes = 524288
allowed_types = ["image/png", "image/jpeg", "application/pdf"]

[uploads.s3]
bucket = "my-private-bucket"
region = "us-east-1"
endpoint = "" # AWS default; set an HTTPS URL for an S3-compatible service
prefix = "uploads"
force_path_style = false
allow_http = false

Use workload credentials or the standard AWS credential provider chain. For local static credentials, put only AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, and an optional AWS_SESSION_TOKEN in .env; never put them in TOML. Compile/run with:

xecute run dev --features s3
cargo run --features s3
# Container image with the optional SDK:
docker build --build-arg CARGO_FEATURES=s3 -t my-app .

For local MinIO, configure endpoint, force_path_style = true, and explicitly set allow_http = true only if the development endpoint uses HTTP. Embedded credentials, query strings, and endpoint paths are rejected. The adapter uses the official AWS SDK, streams retryable file bodies, supplies MIME/checksum metadata, and uses conditional If-None-Match: * writes. It never creates buckets, changes ACLs, or makes objects public. Provision a bucket and scoped PutObject/DeleteObject permissions, plus KMS permissions if required by its encryption policy. Bucket versioning, lifecycle, encryption, and application metadata retention remain operator/application choices.

Runtime users enable xecute/upload for UploadPolicy, UploadService, LocalStorage, and the UploadStorage adapter trait; upload-s3 adds S3Storage. S3Storage::new accepts an application-configured AWS client; from_environment uses the standard credential chain. #[multipart] inside a #[routes] method produces the matching multipart OpenAPI schema and cannot be combined with JSON body metadata. The example Swagger page can submit repeated file fields.

Tests cover invalid batches, count/size limits, request framing limits, generated keys, private storage, temporary-file cleanup, and handled-failure rollback. A local mock S3 endpoint verifies signed conditional PUT, streamed content, metadata, and DELETE; no live cloud bucket or real credentials are used by the tests.

API version groups and separate OpenAPI documents

Generated applications explicitly register version groups in src/server/versions.rs:

/docs/ and /docs/openapi.json continue to describe the unversioned aliases. Each version has its own routes, operation IDs, and schema components; v2 does not automatically inherit v1 resources. Add v2-specific modules/controllers to its router as the contract evolves. Use a separate DI container when a version needs independently constructed provider instances.

use xecute::{ApiVersion, ApiVersions};

let versions = ApiVersions::new()
    .with(ApiVersion::new("v1", v1_router, V1Controller::api_operations())?)?
    .with(ApiVersion::new("v2", v2_router, V2Controller::api_operations())?)?;
let router = versions.mount(axum::Router::new());
let documents = versions.documents("My API")?;

Supply controller paths relative to the group; the router and documented paths receive the same prefix. Canonical labels are v1, v2, etc, with positive u32 version numbers. Invalid labels, duplicate groups, and conflicting contracts fail before serving. The same operation ID/schema name may appear in different version documents. Global application policies wrap all groups.

[api]
versioning_enabled = true

[docs]
enabled = true

Set api.versioning_enabled = false to keep only unversioned aliases. Set docs.enabled = false to hide all Swagger/OpenAPI routes while keeping API routes active. Startup logs include each enabled version's Swagger and OpenAPI URLs. The registration pattern is explicit URL versioning; header-based versioning and automatic deprecation/sunset behavior are not implied.