cosmoswasm - SKILL.md Agent Skill

name: cosmoswasm description: >- Build a CosmWasm sovereign rollup on ev-node with Celestia DA, exposed through one Go SDK. Use when building or extending the cosmoswasm SDK, the executor, the Cosmos app, or the HTTP server.

cosmoswasm — what I want to build

The goal

I want to build a sovereign rollup on ev-node that runs CosmWasm smart contracts, with Celestia as the data availability layer, and wrap the whole thing behind one Go SDK so a developer only has to:

import cosmoswasm ".../apps/cosmos-exec/sdk/cosmoswasm"

…and then call simple methods (SubmitBlob, CommitRoot, QuerySmart, BuildStoreTx / BuildInstantiateTx / BuildExecuteTx) instead of hand-wiring Cosmos SDK modules, the Wasm VM, DA plumbing, Merkle proofs, and protobuf encoding themselves.

How the pieces fit

User app (Go)      →  import cosmoswasm SDK
   │ HTTP
cosmos-exec-grpc   →  HTTP API server (cmd/)
   │
executor           →  Wasm runtime + blob store + state (executor/)
   │
Cosmos SDK app     →  modules: auth, bank, wasm, IBC, params (app/)
   │
ev-node (evcosmos) →  sequencer, P2P, block production, DA sync
   │
Celestia DA        →  off-chain blob storage

The SDK is the product; the executor, server, and app exist to make that one import work. CosmWasm gives us smart contracts; ev-node gives us the rollup node; Celestia keeps big data off-chain and cheap.

Run it locally

go run -tags run_cosmos_wasm ./scripts/run-cosmos-wasm-nodes.go \
  --clean-on-start=true --block-time=2s
# wait for "Cosmos/WASM stack is running"; SDK targets http://127.0.0.1:50051

A few rules to keep

One import: users only ever touch the top-level cosmoswasm package.
Keep real logic in internal/; public files stay thin wrappers over it.
Errors are SDKError{Op, Cause, Hint} — the hint tells the user what to do.
Tests use the mocks (NewMockClient, NewMockDAClient) — no live chain.

TODO

Cosmos app — wire modules (auth, bank, wasm, IBC, params) in app/
Executor — Wasm runtime + blob store + persistent state in executor/
HTTP server — cmd/cosmos-exec-grpc/ with Swagger + auth/CORS/rate-limit
SDK client — NewClientFromConfig, SubmitBlob, QuerySmart
Tx builders — BuildStoreTx, BuildInstantiateTx, BuildExecuteTx
DA layer — namespace, blob submit/retrieve, DABridge to Celestia
Data integrity — Merkle proof (GetProof/VerifyMerkleProof), chunk, compress
Blob-first commit — SubmitBatch → Merkle root → CommitRoot on-chain
Cost estimation — EstimateCost: direct on-chain vs blob-first
Mocks + tests — mock executor/DA, unit tests with no running chain
Examples — quickstart, deploy-contract, dapp-chain
Docs — README, getting-started, architecture, api-reference
Demo apps — frontend, faucet, block/tx explorer (proof, not core)