Migrate to nexum:runtime@0.2.0 (unified error model, identity, capabilities)

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -24,7 +24,7 @@ body:
     id: scope
     attributes:
       label: Scope
-      description: Universal `web3:runtime` change, domain extension (e.g. `shepherd:cow`), runtime-only, or SDK-only?
+      description: Universal `nexum:host` change, domain extension (e.g. `shepherd:cow`), runtime-only, or SDK-only?
   - type: textarea
     id: extra
     attributes:

Cargo.toml

@@ -1,6 +1,6 @@
 [workspace]
 members = [
-    "crates/nxm-engine",
+    "crates/nexum-engine",
     "modules/example",
 ]
 resolver = "2"

README.md

@@ -5,7 +5,9 @@
 
 Shepherd is the [CoW Protocol](https://cow.fi) distribution of **Nexum**, a WebAssembly Component Model runtime for secure, sandboxed execution of capability-scoped modules.
 
-A module compiled against the universal `web3:runtime/headless-module` world runs on any Nexum-compatible host. A module compiled against `shepherd:cow/shepherd-module` additionally gains access to CoW Protocol APIs and order submission — and requires a Shepherd host.
+A module compiled against the universal `nexum:host/event-module` world runs on any Nexum-compatible host. A module compiled against `shepherd:cow/shepherd` additionally gains access to CoW Protocol APIs and order submission — and requires a Shepherd host.
+
+> **Upgrading from 0.1?** See the [Migration Guide](docs/migration/0.1-to-0.2.md) for the full rename table, the new `host-error` model, and the manifest-driven capability negotiation introduced in 0.2.
 
 ## Why
 
@@ -20,12 +22,14 @@ A module compiled against the universal `web3:runtime/headless-module` world run
 
 | Path | Purpose |
 | --- | --- |
-| `crates/nxm-engine/` | Host runtime — wasmtime-based component loader and host implementations. |
+| `crates/nexum-engine/` | The **engine** — a wasmtime-based host *implementation* of the `nexum:host` contract. The reference server runtime. |
+| `wit/nexum-host/` | The **`nexum:host` WIT package** — the host/guest *contract* (interfaces, types, worlds) that every engine implements and every module imports. |
+| `wit/shepherd-cow/` | `shepherd:cow` WIT package — CoW Protocol-specific extensions on top of `nexum:host`. |
 | `modules/example/` | Reference guest module demonstrating the module ABI. |
-| `wit/web3-runtime/` | Universal `web3:runtime` WIT package (csn, identity, local-store, remote-store, msg, logging). |
-| `wit/shepherd-cow/` | `shepherd:cow` WIT package — CoW Protocol-specific extensions. |
 | `docs/` | Architecture, design notes, and the universal primitive taxonomy. Start with [`docs/00-overview.md`](docs/00-overview.md). |
 
+> **Engine vs. host.** "Engine" is a concrete implementation that runs WASM components (today: `nexum-engine`, a wasmtime-based daemon). The `nexum:host` WIT package is the *contract* — the host-imports surface a guest sees. Other engines (mobile, browser) can implement the same `nexum:host` contract; modules built against the contract run on any compliant engine.
+
 ## Building
 
 Shepherd uses [Nix](https://nixos.org/) flakes to pin the toolchain and [just](https://github.com/casey/just) as a task runner.
@@ -51,14 +55,15 @@ Without Nix, you need: Rust (edition 2024, see `rust-toolchain.toml` if present)
 The `docs/` directory contains the design corpus:
 
 - [`00-overview.md`](docs/00-overview.md) — architecture, primitives, WIT worlds
-- [`01-runtime-environment.md`](docs/01-runtime-environment.md) — host runtime
+- [`01-runtime-environment.md`](docs/01-runtime-environment.md) — engine internals (wasmtime, fuel, epoch, ResourceLimiter)
 - [`02-modules-events-packaging.md`](docs/02-modules-events-packaging.md) — module ABI, events, packaging
 - [`03-module-discovery.md`](docs/03-module-discovery.md) — static / ENS / on-chain registry
 - [`04-state-store.md`](docs/04-state-store.md) — local + remote state
 - [`05-sdk-design.md`](docs/05-sdk-design.md) — guest SDK
 - [`06-production-hardening.md`](docs/06-production-hardening.md) — operational concerns
-- [`07-rpc-namespace-design.md`](docs/07-rpc-namespace-design.md) — `csn` namespace
+- [`07-rpc-namespace-design.md`](docs/07-rpc-namespace-design.md) — `chain` namespace
 - [`08-platform-generalisation.md`](docs/08-platform-generalisation.md) — beyond CoW
+- [`migration/0.1-to-0.2.md`](docs/migration/0.1-to-0.2.md) — upgrading from Nexum 0.1
 
 ## Contributing
 

crates/nxm-engine/Cargo.toml → crates/nexum-engine/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
-name = "nxm-engine"
-version = "0.1.0"
+name = "nexum-engine"
+version = "0.2.0"
 edition.workspace = true
 license.workspace = true
 repository.workspace = true
@@ -10,3 +10,6 @@ wasmtime = { version = "45", features = ["component-model"] }
 wasmtime-wasi = "45"
 anyhow = "1"
 tokio = { version = "1", features = ["full"] }
+getrandom = "0.4"
+serde = { version = "1", features = ["derive"] }
+toml = "1"