feat(sdk): rename attribute to #[chain_module], keep #[fai_module] alias

The public macro name was the last product-scoped 'fai' identifier
in the SDK surface. #[chain_module] is now the primary attribute
(README + examples updated); #[fai_module] stays as a delegating
alias so modules written before the rename keep compiling. 0.2.1.

Signed-off-by: flemming-it <sf@flemming.it>

Cargo.lock

@@ -43,7 +43,7 @@ checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
 [[package]]
 name = "chain-module-sdk"
-version = "0.2.0"
+version = "0.2.1"
 dependencies = [
  "chain-module-sdk-macros",
  "serde",
@@ -55,7 +55,7 @@ dependencies = [
 
 [[package]]
 name = "chain-module-sdk-macros"
-version = "0.2.0"
+version = "0.2.1"
 dependencies = [
  "proc-macro2",
  "quote",

Cargo.toml

@@ -6,7 +6,7 @@ members = [
 ]
 
 [workspace.package]
-version = "0.2.0"
+version = "0.2.1"
 edition = "2024"
 authors = ["Dr. Stefan Flemming <chain@flemming.ai>"]
 license = "Apache-2.0"

README.md

@@ -7,7 +7,7 @@ A module written against this crate looks like:
 ```rust
 use chain_module_sdk::prelude::*;
 
-#[fai_module]
+#[chain_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}")))
@@ -16,7 +16,7 @@ fn invoke(_ctx: Context, inputs: Inputs) -> Result<Outputs, ModuleError> {
 
 That single function — plus a `Cargo.toml` listing
 `chain-module-sdk` as a dependency — is the entire module. The
-`#[fai_module]` macro generates the `wit_bindgen` invocation, the
+`#[chain_module]` macro generates the `wit_bindgen` invocation, the
 `Guest` implementation, the type conversions, and the
 `wit_bindgen::export!` glue behind the scenes.
 
@@ -28,7 +28,7 @@ That single function — plus a `Cargo.toml` listing
 | `Outputs::new().with_json(...)?` | building `Vec<(String, Payload)>` by hand |
 | `ModuleError::invalid_input("...")` | constructing WIT `invocation-error` variants |
 | `ctx.emit("progress", ...)` | hand-rolling the `host.emit-event` import (WIT 1.1) |
-| `#[fai_module]` | `wit_bindgen::generate!` + `Guest` impl + `export!` + `#![allow(unsafe_op_in_unsafe_fn)]` |
+| `#[chain_module]` | `wit_bindgen::generate!` + `Guest` impl + `export!` + `#![allow(unsafe_op_in_unsafe_fn)]` |
 
 ## Stability
 

crates/chain-module-sdk-macros/src/lib.rs

@@ -1,6 +1,7 @@
 //! Procedural macros powering `chain-module-sdk`.
 //!
-//! This crate exists only to host the `#[fai_module]` attribute.
+//! This crate exists only to host the `#[chain_module]` attribute
+//! (and its legacy alias `#[fai_module]`).
 //! Module authors should depend on `chain-module-sdk` (which
 //! re-exports the macro), not on this crate directly.
 
@@ -26,7 +27,19 @@ const WIT_INLINE: &str = include_str!("../../../wit/world.wit");
 /// the `wit_bindgen::export!` call. The function can be named
 /// anything — only its signature matters.
 #[proc_macro_attribute]
+pub fn chain_module(_attrs: TokenStream, input: TokenStream) -> TokenStream {
+    expand_module(input)
+}
+
+/// Legacy alias for [`chain_module`], kept so modules written
+/// before the product rename keep compiling. New code uses
+/// `#[chain_module]`.
+#[proc_macro_attribute]
 pub fn fai_module(_attrs: TokenStream, input: TokenStream) -> TokenStream {
+    expand_module(input)
+}
+
+fn expand_module(input: TokenStream) -> TokenStream {
     let user_fn = parse_macro_input!(input as ItemFn);
     let user_fn_name = user_fn.sig.ident.clone();
     let wit_literal = WIT_INLINE;

crates/chain-module-sdk/src/lib.rs

@@ -5,7 +5,7 @@
 //! ```ignore
 //! use chain_module_sdk::prelude::*;
 //!
-//! #[fai_module]
+//! #[chain_module]
 //! fn invoke(_ctx: Context, inputs: Inputs) -> Result<Outputs, ModuleError> {
 //!     let text = inputs.require_text("input")?;
 //!     Ok(Outputs::new().with_text("output", format!("got: {text}")))
@@ -36,9 +36,9 @@ pub use inputs::Inputs;
 pub use outputs::Outputs;
 pub use payload::{BytesValue, FileRef, Payload};
 
-pub use chain_module_sdk_macros::fai_module;
+pub use chain_module_sdk_macros::{chain_module, fai_module};
 
-// Emit-hook plumbing used by the `#[fai_module]` expansion (wasm32)
+// Emit-hook plumbing used by the `#[chain_module]` expansion (wasm32)
 // so `Context::emit` reaches the WIT `emit-event` host import.
 #[doc(hidden)]
 pub use host::__set_emit_hook;
@@ -48,11 +48,12 @@ pub(crate) use host::emit;
 /// every type a typical module needs into scope.
 pub mod prelude {
     pub use super::{
-        BytesValue, Context, FileRef, Inputs, ModuleError, Outputs, Payload, fai_module,
+        BytesValue, Context, FileRef, Inputs, ModuleError, Outputs, Payload, chain_module,
+        fai_module,
     };
 }
 
-/// Internal re-exports the `#[fai_module]` macro expansion depends on.
+/// Internal re-exports the `#[chain_module]` macro expansion depends on.
 ///
 /// Not part of the public API. Anything in this module may change
 /// between SDK patch releases.

examples/echo/Cargo.lock

@@ -34,7 +34,7 @@ checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
 [[package]]
 name = "chain-module-sdk"
-version = "0.1.2"
+version = "0.2.0"
 dependencies = [
  "chain-module-sdk-macros",
  "serde",
@@ -45,7 +45,7 @@ dependencies = [
 
 [[package]]
 name = "chain-module-sdk-macros"
-version = "0.1.2"
+version = "0.2.0"
 dependencies = [
  "proc-macro2",
  "quote",

examples/echo/src/lib.rs

@@ -1,13 +1,13 @@
 //! Minimum-viable F∆I module — echoes the first text input.
 //!
 //! Demonstrates the entire authoring surface: a single function
-//! decorated with `#[fai_module]`. No `wit_bindgen`, no
+//! decorated with `#[chain_module]`. No `wit_bindgen`, no
 //! `unsafe_op_in_unsafe_fn` allow, no `export!` call, no manual
 //! Payload-variant matching.
 
 use chain_module_sdk::prelude::*;
 
-#[fai_module]
+#[chain_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}")))

examples/progress/Cargo.lock

@@ -34,7 +34,7 @@ checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
 [[package]]
 name = "chain-module-sdk"
-version = "0.1.2"
+version = "0.2.0"
 dependencies = [
  "chain-module-sdk-macros",
  "serde",
@@ -45,7 +45,7 @@ dependencies = [
 
 [[package]]
 name = "chain-module-sdk-macros"
-version = "0.1.2"
+version = "0.2.0"
 dependencies = [
  "proc-macro2",
  "quote",

examples/progress/src/lib.rs

@@ -6,7 +6,7 @@
 
 use chain_module_sdk::prelude::*;
 
-#[fai_module]
+#[chain_module]
 fn invoke(ctx: Context, inputs: Inputs) -> Result<Outputs, ModuleError> {
     let text = inputs.require_text("input")?;