flemming-it
cd4457310b
The old 'F∆I Platform' product name and platform@flemming.ai contact survived in docs/NOTICE/descriptions/help text; the product is Ch∆In and the contact is chain@flemming.ai. Generic 'cross-platform/platform-native' left untouched. Signed-off-by: flemming-it <sf@flemming.it>
2.1 KiB
fai-module-sdk
Stable, ergonomic Rust surface for writing Ch∆In modules.
A module written against this crate looks like:
use fai_module_sdk::prelude::*;
#[fai_module]
fn invoke(_ctx: Context, inputs: Inputs) -> Result<Outputs, ModuleError> {
let text = inputs.require_text("input")?;
Ok(Outputs::new().with_text("output", format!("echo: {text}")))
}
That single function — plus a Cargo.toml listing
fai-module-sdk as a dependency — is the entire module. The
#[fai_module] macro generates the wit_bindgen invocation, the
Guest implementation, the type conversions, and the
wit_bindgen::export! glue behind the scenes.
What the SDK gives you
| You get | Instead of |
|---|---|
Inputs::require_text("name") |
manual match payload { Payload::Text(s) => ..., _ => ... } |
Outputs::new().with_json(...)? |
building Vec<(String, Payload)> by hand |
ModuleError::invalid_input("...") |
constructing WIT invocation-error variants |
#[fai_module] |
wit_bindgen::generate! + Guest impl + export! + #![allow(unsafe_op_in_unsafe_fn)] |
Stability
The SDK insulates module code from the underlying WIT contract
(chain:platform, frozen at v1.0 in the platform repo). The
WIT may evolve in additive minor versions or, eventually, a
coordinated v2.0; the SDK absorbs that change so existing
module code keeps compiling.
The SDK ships its own copy of wit/world.wit so that the
proc-macro can embed the contract via include_str! at compile
time. A snapshot test (crates/fai-module-sdk/tests/wit_freeze.rs)
asserts the SHA-256 matches the platform's frozen hash — if the
two ever drift, CI fails.
Versioning
| Track | Stability |
|---|---|
WIT contract (chain:platform) |
Frozen at v1.0 in the platform repo |
fai-module-sdk Rust API |
Semver; v0.x while ergonomics evolve |
| Per-module versions | Each module repo's own concern |
License
Apache-2.0. See LICENSE.
Author: Dr. Stefan Flemming, Flemming.AI chain@flemming.ai Repository: https://git.flemming.ai/fai/module-sdk-rust