hono/mcp v0.2

[MathurAditya724]

Resolves #1259

• Updated the StreamableHTTPTransport class with tests
• Auth Support

[changeset-bot]

🦋 Changeset detected

Latest commit: 1c773d3

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@hono/mcp	Minor

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[himorishige]

Thank you for this amazing middleware contribution!

I've been using your implementation and found I needed the streamableHTTPTransport functionality for a project. Based on your excellent Draft PR, I've extracted and enhanced just the streamableHTTPTransport portion.

I've created a separate PR that focuses solely on the Transport implementation from #1318. If you find it useful, please feel free to incorporate these changes back into #1318.

As a suggestion, since the auth implementation appears to be ongoing, would it make sense to split the streamableHTTPTransport into a separate PR #1392 to move forward incrementally?
This might help get the transport functionality merged sooner while auth work continues.

Thank you again for laying the groundwork with your original implementation!

[MathurAditya724]

Thanks @himorishige, I just completed the auth changes. Need to write the tests but rest all seems good. (Thanks you for pushing me to complete it)

Are there any extra changes you have done in your PR? If yes then kindly create the PR for this branch instead of hono and I can review and merge it.

[himorishige]

Hi @MathurAditya724

As requested, I’ve opened a dedicated PR against your branch: MathurAditya724/hono‑middleware #3. This PR extracts and enhances the StreamableHTTPTransport implementation from your draft PR #1318.

It adds MCP HTTP streaming transport support along with queue management, message size limits, backpressure handling and other improvements, while keeping your original architecture and test suite.

All tests are passing, so if you find these changes useful, please feel free to merge or cherry‑pick them into your auth PR when convenient.

If I’ve misunderstood the correct target or opened the PR in the wrong place, please let me know and I’ll fix it — apologies in advance.

Thank you again for your excellent groundwork on the transport and auth implementation.

[codecov]

Codecov Report

❌ Patch coverage is 81.54860% with 112 lines in your changes missing coverage. Please review.
✅ Project coverage is 49.81%. Comparing base (bd6aad3) to head (eeedb67).
⚠️ Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
packages/mcp/src/sse.ts	0.00%	53 Missing and 14 partials ⚠️
packages/mcp/src/streamable-http.ts	90.43%	21 Missing and 1 partial ⚠️
packages/mcp/src/auth/helpers/authorize.ts	89.47%	6 Missing ⚠️
packages/mcp/src/auth/providers/proxy-provider.ts	93.05%	5 Missing ⚠️
packages/mcp/src/auth/helpers/revoke.ts	80.00%	4 Missing ⚠️
packages/mcp/src/auth/helpers/register.ts	90.32%	3 Missing ⚠️
packages/mcp/src/auth/helpers/token.ts	93.33%	3 Missing ⚠️
packages/mcp/src/auth/middleware/client-auth.ts	96.29%	1 Missing ⚠️
packages/mcp/src/auth/router.ts	97.56%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1318      +/-   ##
==========================================
+ Coverage   48.52%   49.81%   +1.29%     
==========================================
  Files         103      113      +10     
  Lines        3386     3792     +406     
  Branches      867      996     +129     
==========================================
+ Hits         1643     1889     +246     
- Misses       1413     1553     +140     
- Partials      330      350      +20     

Flag	Coverage Δ
firebase-auth	?
mcp	13.60% <81.54%> (+7.67%)	⬆️
trpc-server	?

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[yusukebe]

@MathurAditya724

Can you update the README to describe the new feature and add a changeset?

[MathurAditya724]

I am thinking of updating the docs with more examples and also add things like config for different auth providers, making it easy to integrate them with @hono/mcp auth.

[MathurAditya724]

@yusukebe should we merge this and I'll add the examples later, or do you want me to add the examples first?

[yusukebe]

Hi @MathurAditya724 !

I think merging this first and adding the examples later is good. I'll review this later!

[pkg-pr-new]

@hono/ajv-validator

npm i https://pkg.pr.new/@hono/ajv-validator@1318

@hono/arktype-validator

npm i https://pkg.pr.new/@hono/arktype-validator@1318

@hono/auth-js

npm i https://pkg.pr.new/@hono/auth-js@1318

@hono/bun-compress

npm i https://pkg.pr.new/@hono/bun-compress@1318

@hono/bun-transpiler

npm i https://pkg.pr.new/@hono/bun-transpiler@1318

@hono/casbin

npm i https://pkg.pr.new/@hono/casbin@1318

@hono/class-validator

npm i https://pkg.pr.new/@hono/class-validator@1318

@hono/clerk-auth

npm i https://pkg.pr.new/@hono/clerk-auth@1318

@hono/cloudflare-access

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@hono/conform-validator

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@hono/effect-validator

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@hono/esbuild-transpiler

npm i https://pkg.pr.new/@hono/esbuild-transpiler@1318

@hono/eslint-config

npm i https://pkg.pr.new/@hono/eslint-config@1318

@hono/event-emitter

npm i https://pkg.pr.new/@hono/event-emitter@1318

@hono/firebase-auth

npm i https://pkg.pr.new/@hono/firebase-auth@1318

@hono/graphql-server

npm i https://pkg.pr.new/@hono/graphql-server@1318

@hono/hello

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@hono/mcp

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@hono/medley-router

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@hono/node-ws

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@hono/oauth-providers

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@hono/oidc-auth

npm i https://pkg.pr.new/@hono/oidc-auth@1318

@hono/otel

npm i https://pkg.pr.new/@hono/otel@1318

@hono/prometheus

npm i https://pkg.pr.new/@hono/prometheus@1318

@hono/qwik-city

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@hono/react-compat

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@hono/react-renderer

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@hono/sentry

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@hono/session

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@hono/ssg-plugins-essential

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@hono/standard-validator

npm i https://pkg.pr.new/@hono/standard-validator@1318

@hono/stytch-auth

npm i https://pkg.pr.new/@hono/stytch-auth@1318

@hono/swagger-editor

npm i https://pkg.pr.new/@hono/swagger-editor@1318

@hono/swagger-ui

npm i https://pkg.pr.new/@hono/swagger-ui@1318

@hono/trpc-server

npm i https://pkg.pr.new/@hono/trpc-server@1318

@hono/tsyringe

npm i https://pkg.pr.new/@hono/tsyringe@1318

@hono/typebox-validator

npm i https://pkg.pr.new/@hono/typebox-validator@1318

@hono/typia-validator

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@hono/ua-blocker

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@hono/valibot-validator

npm i https://pkg.pr.new/@hono/valibot-validator@1318

@hono/zod-openapi

npm i https://pkg.pr.new/@hono/zod-openapi@1318

@hono/zod-validator

npm i https://pkg.pr.new/@hono/zod-validator@1318

commit: eeedb67

[yusukebe]

Hi @MathurAditya724

I told you you didn't have to add examples first, but can you add them now? Sorry! I've tried the SSE feature of this branch, but it does not work as I expected. So, I would like to know an example.

[MathurAditya724]

Yup already working on them, will ping you once completed

[yusukebe]

@MathurAditya724 Hi Aditya!

How is working on creating examples?

[MathurAditya724]

Sorry for the delay on this, got busy with work. Will finish this by tomorrow

[yusukebe]

@MathurAditya724 No problem!

[yusukebe]

Hey @MathurAditya724 !

Sorry for the delay on this, got busy with work. Will finish this by tomorrow

What's going on with this?