cw-component-template

Starter template for building WAVS components for CosmWasm chains.

It ships a working pair:

• contract/ — a minimal CosmWasm contract (event-trigger-contract) that pushes messages via an AddMessage execute and emits a new-message event keyed by an auto-incrementing trigger id.
• component/ — a Rust WASI component (component-example) that listens for that event, echoes the payload back as a bincode-encoded MessageWithId { trigger_id, message }, and demonstrates the host bridge (config-var, log).

Fork it, rename the crates, and replace the body of inner() in component/src/lib.rs with your service logic.

Status

Versions are pinned to match cw-middleware v0.3.0:

	Version
cosmwasm-std	=3.0.2 (cosmwasm_1_2)
cw-storage-plus / cw2	3.0.1 / 3.0.0
wavs-types	=2.0.0-rc.8 (cosmwasm feature)
wit-bindgen / wit-bindgen-rt	0.47.0 / 0.44.0
wstd / wasip2	0.5.3 / 1.0.1
bincode	2.0.1 (serde feature)

The WIT world is vendored at wit/ from Lay3rLabs/wavs-wasi's wavs:operator@2.4.0 world. Refresh with task wit:fetch.

This template builds against the canonical cw-wavs-trigger-simple event shape but ships its own bespoke trigger contract so you can mutate the storage / event keys / execute API freely. If you want to consume the audited cw-middleware trigger contract directly instead of forking it, depend on cw-wavs-trigger-api from cw-middleware and parse PushMessageEvent instead of NewMessageEvent.

Layout

.
├── Cargo.toml              # workspace root; pins versions used by both crates
├── Taskfile.yml            # build / check / fmt / lint / wit:fetch entry points
├── component/              # WAVS WASI component (cdylib, target wasm32-wasip2)
│   ├── Cargo.toml
│   └── src/
│       └── lib.rs          # wit_bindgen::generate! + Guest impl
├── contract/               # CosmWasm contract (cdylib + rlib, target wasm32-unknown-unknown)
│   ├── Cargo.toml
│   └── src/
│       ├── contract.rs     # entry_point instantiate/execute/query/migrate
│       ├── event.rs        # NewMessageEvent + parser (shared with component)
│       ├── msg.rs          # InstantiateMsg / ExecuteMsg / QueryMsg / MigrateMsg
│       └── state.rs        # MESSAGES Map<u64, Message>
└── wit/                    # vendored WAVS operator world (wavs:operator@2.4.0)
    ├── operator.wit
    └── deps/               # wasi-* + wavs-types dependency wits

Prerequisites

• Rust toolchain ≥ 1.88 with the wasm32-wasip2 and wasm32-unknown-unknown targets

  rustup target add wasm32-wasip2 wasm32-unknown-unknown

• Task (optional but the recipes assume it)

Build

task build           # contract + component
task build:contract  # contract only (artifacts/event_trigger_contract.wasm)
task build:component # component only (artifacts/component_example.wasm)

Both artifacts land under artifacts/.

Develop

task check           # cargo check --workspace
task fmt             # cargo fmt --all
task lint            # fmt check + clippy -D warnings
task test            # cargo test --workspace

Wiring this template into a WAVS service

1. Deploy event_trigger_contract.wasm to your target Cosmos chain.
2. Upload component_example.wasm to your WAVS node (e.g. wavs-cli component upload).
3. Configure a service workflow whose trigger is a cosmos-contract-event matching the new-message event type emitted by the contract, and whose component is the uploaded artifact.
4. To exercise it: call AddMessage { data } on the contract; the WAVS node will fire Guest::run, the component echoes back, and the response flows into the configured submission handler (typically one of the ECDSA / BLS / Mirror service-handler contracts from cw-middleware).

The bincode envelope produced by the component (MessageWithId { trigger_id, message }) is byte-compatible with cw-middleware's reference echo-with-id component, so any submission plumbing wired for that flow will decode this template's responses unchanged.

Layout decisions

• Vendored WIT (rather than a submodule or git dep) keeps the template buildable in environments without network access during compile. Refresh with task wit:fetch.
• Bespoke contract is shipped for ergonomics — the goal of this template is "fork and customize," not "consume an audited primitive." For the audited path, see cw-middleware's cw-wavs-trigger-simple.
• No SDK dep on cw-wavs-sdk — the component decodes its own event locally via event_trigger_contract::event::NewMessageEvent, keeping the dep graph minimal and avoiding a tight coupling to cw-middleware's release cycle.