# @modelcontextprotocol/hono@2.0.0

Category: agent-infrastructure
Published: 2026-07-27T23:55:26Z
Source: [MCP TypeScript SDK releases](https://github.com/modelcontextprotocol/typescript-sdk/releases/tag/%40modelcontextprotocol%2Fhono%402.0.0)
Agent usefulness: 82/100
Confidence: 0.96
Content mode: release-watch
Verified: 2026-09-23T10:17:23.833Z
Tags: mcp, sdk, typescript

## Human Summary
Release 2.0.0 of @modelcontextprotocol/hono introduces initial SDK v2 beta support for the 2026-07-28 specification revision, dual ESM/CJS builds, and stricter Content-Type validation returning 415 for non-JSON POST requests.

## Agent Summary
@modelcontextprotocol/hono@2.0.0 released with MCP 2026-07-28 spec support, dual ESM/CJS exports via tsdown, and stricter Content-Type parsing rejecting non-application/json POSTs with 415 Unsupported Media Type. Exports isJsonContentType helper.

## Body
@modelcontextprotocol/hono@2.0.0 marks the first beta release of SDK v2 with support for the MCP 2026-07-28 specification revision. The release ships CommonJS builds (.cjs/.d.cts) alongside ESM (.mjs/.d.mts) with package exports configured for require() support. Additionally, Content-Type validation for POST requests has been updated to parse the media type rather than relying on substring matching; requests lacking an application/json media type now return 415 Unsupported Media Type. A new helper, isJsonContentType(header), is exported for custom transport and adapter authors. Dependency @modelcontextprotocol/server was updated to 2.0.0.

## Recommended actions
- Consult the v1-to-v2 upgrade guide (docs/migration/upgrade-to-v2.md) and the 2026-07-28 specification adoption guide (docs/migration/support-2026-07-28.md).
- Ensure client POST requests include a valid Content-Type header matching application/json to avoid 415 Unsupported Media Type responses.
- Adopt the exported isJsonContentType(header) helper if authoring custom framework adapters or transports using classifyInboundRequest or PerRequestHTTPServerTransport.

## Sponsors
No sponsor placement attached.

## Agent-readable Sponsor Surface
Sponsor inventory is available at /api/sponsors.json with useCases, pricing, API/docs URLs, targetAgents, constraints, CTA URL, commercial disclosure fields, sourceOfTruthUrl, constraintsLastVerifiedAt, constraintsRefreshCadence, driftHandlingPolicy, and constraintPolicy.