microsoft/wassette v0.7.1

v0.7.1

Repository: microsoft/wassette

Tag: v0.7.1

Published: 2026-09-12T03:57:30Z

Prerelease: no

Release notes:

Highlights

A patch release. It updates the WebAssembly runtime to pick up two Wasmtime security fixes, and makes wassette tool invoke able to call the tools a component exports.

Security

Wasmtime moves from 47.0.3 to 47.0.4, picking up fixes for two advisories published on 2026-08-20 (#799). Wassette 0.6.0 and 0.7.0 both shipped 47.0.3, which is affected by both:

• RUSTSEC-2026-0269 (GHSA-vqjp-4c8c-hfgg) — filesystem sandbox escape when paths or symlinks contain trailing slashes. This one is worth a look if you grant components filesystem access through a policy.
• RUSTSEC-2026-0268 (GHSA-x84v-gj2h-g759) — guest controlled-size host heap allocation through WASIp3 streams.

Hyper moves from 1.11.0 to 1.11.1 in the same change.

wassette tool invoke

• wassette tool invoke can now call the tools a component exports (#794). Tool-name resolution ran through the in-memory registry, which only the server's background restore populates, so in a one-shot CLI process every component tool looked absent — even though tool list and tool read could describe it, because those already fall back to the metadata cached on disk. tool invoke now hydrates the registry from that same validated metadata, so resolution is an ordinary in-memory lookup rather than a second lookup path. Hydration is scoped to tool invoke and skipped when the named tool is a built-in.
• Registering a component from metadata compiles nothing, so the tool-call path now ensures the component is loaded once its id is known. That also closes a server-side gap: during a restore the registry holds tool schemas before instances exist, so a tools/call in that window could resolve a tool and then fail to execute it (#794).

Component load concurrency

Putting an on-demand load on the tool-call path makes a pre-existing race reachable from ordinary tool calls, so this release also hardens component loading (#794):

• A per-component load guard is held across every path that compiles or removes a component's files: explicit loads (across staging as well as compilation, since staging replaces the .wasm, the metadata and the precompiled cache), unloads (across artifact removal and registry cleanup), on-demand loads, the background restore, and startup restoration. Different components still load in parallel; racing loads of one component compile it once.
• Registry hydration is published in a single atomic write, so a reader sees either the pre-hydration or the fully hydrated registry — never a half-registered state in which a tool name exported by two components resolves to whichever happened to be registered first.

Dependencies

Dependency bumps are excluded from the generated list below, so for the record: this release also refreshes rmcp 3.1.4 → 3.2.0, tokio-rustls 0.26.4 → 0.26.5, wasmparser 0.257.1 → 0.258.0, wat 1.256.0 → 1.258.0, rcgen 0.14.9 → 0.14.10, four GitHub Actions, and the mcp-inspector harness dependencies (#795, #796, #797, #801, #802, #803, #804, #805, #806).

Build and test

• The nightly coverage job compiles again, after raising the recursion limit (#794).
• The stateless MCP peer fixture declares its protocol revision in request _meta rather than through the initialize handshake, the way a real stateless client does, and asserts that _meta takes precedence over the peer's negotiated state (#807).

No breaking changes. Upgrading from 0.7.0 needs no configuration changes.

What's Changed

• chore: update winget and homebrew for v0.7.0 by @asw101 in https://github.com/microsoft/wassette/pull/792
• fix(cli): hydrate the registry from cached metadata so tool invoke works by @asw101 in https://github.com/microsoft/wassette/pull/794
• Update Wasmtime to address security advisories by @asw101 with @Copilot in https://github.com/microsoft/wassette/pull/799
• test(mcp): use request metadata for the stateless peer fixture by @asw101 in https://github.com/microsoft/wassette/pull/807
• chore(release): bump version to 0.7.1 by @asw101 in https://github.com/microsoft/wassette/pull/808

Full Changelog: https://github.com/microsoft/wassette/compare/v0.7.0...v0.7.1

Downloads

Linux

• AMD64 (tar.gz)
• ARM64 (tar.gz)

macOS (Darwin)

• AMD64/Intel (tar.gz)
• ARM64/Apple Silicon (tar.gz)

Windows

• AMD64 (zip)
• ARM64 (zip)

Install

All Platforms (Shell Script)

curl -fsSL https://raw.githubusercontent.com/microsoft/wassette/main/scripts/install.sh | WASSETTE_GITHUB_REPO=microsoft/wassette bash

This will detect your platform and install the latest wassette binary to your $PATH.

Usage

# Local MCP client integration (stdio)
wassette run

# Remote MCP server (Streamable HTTP)
wassette serve