How to author custom commands for the test-x-fern-global-parameters-extension CLI using the co-generated SDK.
test-x-fern-global-parameters-extensionThe test-x-fern-global-parameters-extension CLI supports user-authored custom commands that are
compiled into the binary alongside the auto-generated API commands.
Custom commands get a fully-wired SDK client that inherits the CLI's
auth, retries, TLS, base URL, and global headers — zero configuration required.
cli/test-x-fern-global-parameters-extension/custom.rs ← Your command handlers (protected by .fernignore)
cli/test-x-fern-global-parameters-extension/sdk.rs ← Generated bridge: client() + block_on()
cli/test-x-fern-global-parameters-extension/main.rs ← Generated entrypoint (calls custom::register)
test-x-fern-global-parameters-extension-sdk/ ← Co-generated typed SDK crate
test-x-fern-global-parameters-extension-types/ ← Co-generated typed model cratecli/test-x-fern-global-parameters-extension/custom.rsThis file is protected by .fernignore — fern generate will never
overwrite it. Register commands in the register() function:
use test_x_fern_global_parameters_extension_sdk::api::*;
pub fn register(app: CliApp) -> CliApp {
let app = app.command(
clap::Command::new("get")
.about("Run products get")
.arg(clap::Arg::new("regionId").required(true))
.arg(clap::Arg::new("productId").required(true))
,
|matches, ctx| {
let region_id = matches.get_one::<String>("regionId").unwrap();
let product_id = matches.get_one::<String>("productId").unwrap();
let client = super::sdk::client(ctx);
let result = super::sdk::block_on(
client.products.get(region_id, product_id),
)?;
println!("{}", serde_json::to_string_pretty(&result).unwrap());
Ok(())
},
);
app
}Then build and test:
cargo build
test-x-fern-global-parameters-extension get <regionId> <productId>The super::sdk::client(ctx) call returns a test_x_fern_global_parameters_extension_sdk::api::Client
with the following sub-clients:
| Field | Type | Description |
|---|---|---|
client.products | test_x_fern_global_parameters_extension_sdk::api::ProductsClient | products operations |
Get the SDK client (execution-sharing, fully authenticated):
let client = super::sdk::client(ctx);Run an async SDK call from a sync handler:
let result = super::sdk::block_on(
client.some_resource.some_method(args),
)?;Use typed models for request/response serialization:
use test_x_fern_global_parameters_extension_sdk::api::*;| File | Regenerated? | Notes |
|---|---|---|
cli/test-x-fern-global-parameters-extension/custom.rs | No | Protected by .fernignore |
cli/test-x-fern-global-parameters-extension/sdk.rs | Yes | Bridges AppContext → SDK client |
cli/test-x-fern-global-parameters-extension/main.rs | Yes | Calls custom::register(app) |
test-x-fern-global-parameters-extension-sdk/ | Yes | Co-generated typed SDK crate |
test-x-fern-global-parameters-extension-types/ | Yes | Co-generated typed models |
After running fern generate, your custom.rs is preserved. All
generated code (SDK, types, glue, main.rs) is updated to match the
latest API spec. If the SDK surface changes (renamed methods, new
sub-clients), update your custom.rs to match.
# Build the CLI (includes custom commands)
cargo build
# Run your custom command
test-x-fern-global-parameters-extension <your-command> [args]
# Run with verbose output for debugging
RUST_LOG=debug test-x-fern-global-parameters-extension <your-command> [args]37dc173
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