HandoffProbe v0.2.0

HandoffProbe v0.2.0 is a release-quality and product-coherence release for defensive A2A 1.0 → MCP 2026-07-28 handoff-security testing.

Highlights

• Exactly 22 stable attacks: 12 P0 and 10 P1
• Stable CLI: test, list, explain, --version, --help
• Report schema remains 1
• Deterministic exit semantics remain 0 / 1 / 2 / 3
• Reusable source-backed GitHub Action remains supported
• Narrower npm package boundary for the stable release build
• Phase 9 crossing-corpus work remains research/conformance tooling and is not a new public CLI/API surface
• Node.js requirement remains >=24 <25

Install

npm install --save-dev --save-exact handoffprobe@0.2.0

One-shot execution:

npm exec --yes --package=handoffprobe@0.2.0 -- handoffprobe --version
npm exec --yes --package=handoffprobe@0.2.0 -- handoffprobe test --target secure

Publication verification

• npm package: handoffprobe@0.2.0
• Package files: 287
• npm shasum: dcc638b0b8542306f112fe1c4375df632eb12db5
• npm integrity: sha512-7Yt9XEfsR+hPY4nCfvc3WH7tHkLE/7p6+HSMmo9cg7mxY6Q2JZWSPUXVJ2hOQ9peADFORmBBvSiOqAYlNzqA7w==
• SHA-256: 1d6e438182a4ecbf3c0dae00df7ad92ead40ad8fca8c6a99e7374048c04391d4
• Immutable release commit: b0fc2a8abe1df36e526536d714418a9842be2f77

Clean external installation and execution were verified after publication, including all 22 stable attacks against the bundled secure target.

Full technical release notes are available in docs/V0_2_0_RELEASE_NOTES.md.

Commercial support

HandoffProbe remains free and open source under Apache-2.0.

Teams applying HandoffProbe to real agent systems can work with Heaviside Solutions on authorized Handoff Security Assessments, custom adapters and integrations, private organization-specific test packs, and technical onboarding or enterprise support.

Need help testing a real agent handoff? https://heaviside-solutions.com/kontakt

HandoffProbe v0.1.1

HandoffProbe v0.1.1

Security maintenance release for the supported HandoffProbe 0.1.x line.

Security maintenance

• updates the transitive qs dependency from 6.15.3 to patched 6.16.0
• preserves the existing HandoffProbe behavior and public contracts
• no new attack IDs, adapters, schemas or CLI features
• no Phase 8 or Phase 9 implementation work included

Stable scope

• A2A 1.0 → MCP 2026-07-28 baseline
• exactly 22 stable attacks
• bundled secure and intentionally vulnerable fixtures
• terminal, JSON and Markdown reporters
• deterministic exit codes 0, 1, 2 and 3
• report schema version 1
• reusable GitHub Action
• local-first execution

Install and run

npx --yes --package=handoffprobe@0.1.1 handoffprobe --version
npx --yes --package=handoffprobe@0.1.1 handoffprobe test

Expected secure result: 22 PASS / 0 FAIL / 0 ERROR.

Composition-security demonstration:

npx --yes --package=handoffprobe@0.1.1 handoffprobe test --target vulnerable --test HP-AUTH-001

The vulnerable demonstration reports the HIGH finding and exits with security code 1.

Release integrity

• Release commit: 8e58c2f6553c735bec3857945ca5afde8c8a3177
• npm package: handoffprobe@0.1.1
• npm shasum: fa26c211b93edeada7503ded85cc4a2286b0845a
• SHA-256: 06b18a038f471189c0a03c36f394672edf4849b83b0952f2233dbd6465f73a31
• npm integrity: sha512-l2k8re073RqSXYUOqTVMirGaZq2f65F8B9WDh2HQKXQ89NofIG6dsmrC9+bopSNZ/w6ClLC0pjFJP4j4r2eg8g==
• package files: 295

The GitHub release asset is the exact tarball that was tested locally and published to npm.

Safety boundary

Use HandoffProbe only with bundled synthetic fixtures, systems you own, controlled test environments, or targets for which you have explicit authorization.

HandoffProbe v0.1.0

HandoffProbe v0.1.0

First public release of HandoffProbe, an open-source defensive security testing CLI for checking whether security properties survive AI-agent protocol handoffs.

v0.1.0 scope

• A2A 1.0 → MCP 2026-07-28 baseline
• exactly 22 stable attacks: 12 P0 and 10 P1
• bundled secure and intentionally vulnerable fixtures
• terminal, JSON and Markdown reporters
• deterministic exit codes 0, 1, 2 and 3
• report schema version 1
• reusable GitHub Action with redacted evidence
• local-first execution with no paid AI API or hosted service required

Install and run

npx --yes --package=handoffprobe@0.1.0 handoffprobe --version
npx --yes --package=handoffprobe@0.1.0 handoffprobe test

Expected secure result: 22 PASS / 0 FAIL / 0 ERROR.

Primary composition-security demonstration:

npx --yes --package=handoffprobe@0.1.0 handoffprobe test --target vulnerable --test HP-AUTH-001

Expected result: HP-AUTH-001 reports a HIGH finding and exits with code 1.

The demonstration concerns a composition invariant failure at the handoff boundary; it does not claim that A2A or MCP is inherently insecure.

Release integrity

• Release commit: 90fdd691b390c420e3288383ad7efa7e0fb69e6f
• npm package: handoffprobe@0.1.0
• npm shasum: 2aa56211d7559cac2cf2052275af45331fba6663
• SHA-256: 3ea4936980893f893e072bf6a378234da8777b1becf494493ff3ffaf4755163a
• npm integrity: sha512-fdDa8/KHmxjfwxcoQMsiLdKjSokFn70nXJhq9mL8ZpBph+trV0uwTU4wCchTW1YahmG16+eDD4PjpcJj7bJjkQ==
• package files: 295

Safety boundary

Use HandoffProbe only with bundled synthetic fixtures, systems you own, controlled test environments, or targets for which you have explicit authorization.