What's Changed
v4.0.0 is a major release with breaking changes. See docs/MIGRATION-v4.md for a full migration guide. This release includes a large number of changes. The items below are the most significant. For the complete list, see the full changelog at the end of this document.
Monorepo split & package rename
The single hedera-agent-kit package has been split into a family of @hashgraph-scoped packages. Framework integrations are now distributed as dedicated toolkits, each bundling only the dependencies it needs:
@hashgraph/hedera-agent-kit- core APIs, types, and plugin system@hashgraph/hedera-agent-kit-langchain@hashgraph/hedera-agent-kit-ai-sdk@hashgraph/hedera-agent-kit-elizaos@hashgraph/hedera-agent-kit-mcp
Plugins have moved to the /plugins subpath and must now be passed explicitly - an empty plugins array results in zero tools. Deprecated aliases (coreHTSPlugin, coreSCSPlugin, coreQueriesPlugin) have been removed.
New Google ADK toolkit
Added a first-class integration with the Google Agent Development Kit, including runnable examples.
Universal Hooks and Policy System
Introduced a cross-framework hooks and policy engine that lets you audit, gate, and transform tool calls - enabling use cases like audit trails, allow/deny lists, and policy enforcement across all supported agent frameworks.
Docs & ecosystem
- New migration guide (MIGRATION-v4.md)
- New Hooks and Policies guide (HOOKS_AND_POLICIES.md)
- ADR for the package split (adr/005-package-split-monorepo.md)
- Hedera T3N plugin added to the plugin listing (#640)
New Contributors
Full Changelog: v3.8.2...v4.0.0
