[PR #299] feat: header metadata support #245

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opened 2026-10-18 21:12:58 +00:00 by bsakaguchi · 0 comments

bsakaguchi commented

2026-10-18 21:12:58 +00:00

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📋 Pull Request Information

Original PR: https://github.com/open-webui/mcpo/pull/299
Author: @Hsienz
Created: 6/17/2026
Status: 🔄 Open

Base: dev ← Head: streamable-http-metadata-support

📝 Commits (6)

788ff92 Merge pull request #287 from open-webui/dev
410e672 chore: udpate mcp 1.17.0 to 1.28.0
bf2bc62 feat: send metadata when enable client-header-forwarding
9938344 feat: add client-header-forwarding to cli
bdb0a48 refactor: change server name placeholder
7e99ed1 feat: metadata support

📊 Changes

5 files changed (+90 additions, -27 deletions)

View changed files

📝 src/mcpo/__init__.py (+5 -1)
📝 src/mcpo/main.py (+11 -0)
📝 src/mcpo/utils/headers.py (+1 -2)
📝 src/mcpo/utils/main.py (+4 -4)
📝 uv.lock (+69 -20)

📄 Description

Pull Request Checklist

Before submitting, make sure you've checked the following:

Target branch: Please verify that the pull request targets the dev branch.
Description: Provide a concise description of the changes made in this pull request.
Changelog: Ensure a changelog entry following the format of Keep a Changelog is added at the bottom of the PR description.
Dependencies: Are there any new dependencies? Have you updated the dependency versions in the documentation?
Testing: Have you written and run sufficient tests to validate the changes?
Code review: Have you performed a self-review of your code, addressing any coding standard issues and ensuring adherence to the project's coding standards?
Prefix: To clearly categorize this pull request, prefix the pull request title using one of the following:
- BREAKING CHANGE: Significant changes that may affect compatibility
- build: Changes that affect the build system or external dependencies
- ci: Changes to our continuous integration processes or workflows
- chore: Refactor, cleanup, or other non-functional code changes
- docs: Documentation update or addition
- feat: Introduces a new feature or enhancement to the codebase
- fix: Bug fix or error correction
- i18n: Internationalization or localization changes
- perf: Performance improvement
- refactor: Code restructuring for better maintainability, readability, or scalability
- style: Changes that do not affect the meaning of the code (white space, formatting, missing semi-colons, etc.)
- test: Adding missing tests or correcting existing tests
- WIP: Work in progress, a temporary label for incomplete or ongoing work

Changelog Entry

Description

Update mcp package so that ClientSession.tool_call() function support meta parameter.

So we can pass unused meta to tool call from exist client-header-forwarding functionality.

Also, implementing the client-header-forwarding to cli command ONLY for streamable-http because I rarely use other type and not able to testing

Added

Send unused meta from client-header-forwarding functionality to tool_call

Add client-header-forwarding to cli command for streamable-http type

usage:

mcpo --port 8001 --type streamable-http --client-header-forwarding '{"enabled":true,"whitelist":["*"]}' -- http://localhost:8000/mcp

mcpo --port 8001 --config config.json

See here for format of config.json

Changed

Update mcp package from 0.17.0 to 0.28.0 for meta suporting

Additional Information

You need to add something like middleware to get meta field
e.g.

// in Programs.cs
builder
    .Services.AddMcpServer()
    .WithHttpTransport(options =>
    {
        options.Stateless = true;
    })
    .WithToolsFromAssembly();

builder.Services.AddHttpContextAccessor();

var app = builder.Build();
app.Use(
    async (ctx, next) =>
    {
        ctx.Request.EnableBuffering();

        using var reader = new StreamReader(ctx.Request.Body, leaveOpen: true);

        var body = await reader.ReadToEndAsync();
        var bodyObject = JObject.Parse(body);

        var auth = bodyObject?["params"]?["_meta"]?["headers"]?["authorization"]?.ToString();
        if (auth != null)
        {
            Console.WriteLine(body);
            ctx.Request.Headers.TryAdd("Authorization", auth);
        }

        ctx.Request.Body.Position = 0;

        await next();
    }
);
app.MapMcp("/mcp");

// in Tool.cs
[McpServerToolType]
internal class HeaderTest
{
    [McpServerTool, Description("this function is use for test, if header is sent to server")]
    public static async Task<string> HeaderTesting(IHttpContextAccessor accessor)
    {
        var request = accessor.HttpContext?.Request;


        foreach (var header in accessor.HttpContext!.Request.Headers)
        {
            Console.WriteLine($"{header.Key}: {header.Value}");
        }
        return "OK";
    }
}

Screenshots or Videos

Left panel is mcpo log
Right panel is MCP server log
You can see Authorization appear in the MCP server log

_{🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.}

## 📋 Pull Request Information **Original PR:** https://github.com/open-webui/mcpo/pull/299 **Author:** [@Hsienz](https://github.com/Hsienz) **Created:** 6/17/2026 **Status:** 🔄 Open **Base:** `dev` ← **Head:** `streamable-http-metadata-support` --- ### 📝 Commits (6) - [`788ff92`](https://github.com/open-webui/mcpo/commit/788ff92e5288a899a743a252edd5748f4ad4ab1f) Merge pull request #287 from open-webui/dev - [`410e672`](https://github.com/open-webui/mcpo/commit/410e672cbe0d8b00fc86cb46003d6b836e63de04) chore: udpate mcp 1.17.0 to 1.28.0 - [`bf2bc62`](https://github.com/open-webui/mcpo/commit/bf2bc6220d324becfc98daa3ada0b6acd0bddb70) feat: send metadata when enable client-header-forwarding - [`9938344`](https://github.com/open-webui/mcpo/commit/99383447b0aa6f1ea091cb1a94c3fa18b6139b99) feat: add client-header-forwarding to cli - [`bdb0a48`](https://github.com/open-webui/mcpo/commit/bdb0a48a291b80e72a08fe01d9b0dec4ad42be11) refactor: change server name placeholder - [`7e99ed1`](https://github.com/open-webui/mcpo/commit/7e99ed1dfca444a5568ff38ffcc596b58eee5d87) feat: metadata support ### 📊 Changes **5 files changed** (+90 additions, -27 deletions) <details> <summary>View changed files</summary> 📝 `src/mcpo/__init__.py` (+5 -1) 📝 `src/mcpo/main.py` (+11 -0) 📝 `src/mcpo/utils/headers.py` (+1 -2) 📝 `src/mcpo/utils/main.py` (+4 -4) 📝 `uv.lock` (+69 -20) </details> ### 📄 Description # Pull Request Checklist **Before submitting, make sure you've checked the following:** - [x] **Target branch:** Please verify that the pull request targets the `dev` branch. - [x] **Description:** Provide a concise description of the changes made in this pull request. - [x] **Changelog:** Ensure a changelog entry following the format of [Keep a Changelog](https://keepachangelog.com/) is added at the bottom of the PR description. - [ ] **Dependencies:** Are there any new dependencies? Have you updated the dependency versions in the documentation? - [x] **Testing:** Have you written and run sufficient tests to validate the changes? - [x] **Code review:** Have you performed a self-review of your code, addressing any coding standard issues and ensuring adherence to the project's coding standards? - [x] **Prefix:** To clearly categorize this pull request, prefix the pull request title using one of the following: - **BREAKING CHANGE**: Significant changes that may affect compatibility - **build**: Changes that affect the build system or external dependencies - **ci**: Changes to our continuous integration processes or workflows - **chore**: Refactor, cleanup, or other non-functional code changes - **docs**: Documentation update or addition - **feat**: Introduces a new feature or enhancement to the codebase - **fix**: Bug fix or error correction - **i18n**: Internationalization or localization changes - **perf**: Performance improvement - **refactor**: Code restructuring for better maintainability, readability, or scalability - **style**: Changes that do not affect the meaning of the code (white space, formatting, missing semi-colons, etc.) - **test**: Adding missing tests or correcting existing tests - **WIP**: Work in progress, a temporary label for incomplete or ongoing work # Changelog Entry ### Description Update mcp package so that ClientSession.tool_call() function support meta parameter. So we can pass unused meta to tool call from exist client-header-forwarding functionality. Also, implementing the client-header-forwarding to cli command ONLY for streamable-http because I rarely use other type and not able to testing ### Added - Send unused meta from client-header-forwarding functionality to tool_call - Add client-header-forwarding to cli command for streamable-http type usage: ```sh mcpo --port 8001 --type streamable-http --client-header-forwarding '{"enabled":true,"whitelist":["*"]}' -- http://localhost:8000/mcp ``` ```sh mcpo --port 8001 --config config.json ``` See [here](https://github.com/open-webui/mcpo/pull/251/changes#diff-4e26a9bda74f3a6533df6aef91c81f92b0757e82278daafa22c7c8e4f3483dbd) for format of config.json ### Changed - Update mcp package from 0.17.0 to 0.28.0 for meta suporting --- ### Additional Information You need to add something like middleware to get meta field e.g. ```cs // in Programs.cs builder .Services.AddMcpServer() .WithHttpTransport(options => { options.Stateless = true; }) .WithToolsFromAssembly(); builder.Services.AddHttpContextAccessor(); var app = builder.Build(); app.Use( async (ctx, next) => { ctx.Request.EnableBuffering(); using var reader = new StreamReader(ctx.Request.Body, leaveOpen: true); var body = await reader.ReadToEndAsync(); var bodyObject = JObject.Parse(body); var auth = bodyObject?["params"]?["_meta"]?["headers"]?["authorization"]?.ToString(); if (auth != null) { Console.WriteLine(body); ctx.Request.Headers.TryAdd("Authorization", auth); } ctx.Request.Body.Position = 0; await next(); } ); app.MapMcp("/mcp"); ``` ```cs // in Tool.cs [McpServerToolType] internal class HeaderTest { [McpServerTool, Description("this function is use for test, if header is sent to server")] public static async Task<string> HeaderTesting(IHttpContextAccessor accessor) { var request = accessor.HttpContext?.Request; foreach (var header in accessor.HttpContext!.Request.Headers) { Console.WriteLine($"{header.Key}: {header.Value}"); } return "OK"; } } ``` ### Screenshots or Videos Left panel is mcpo log Right panel is MCP server log You can see Authorization appear in the MCP server log <img width="1918" height="1077" alt="image" src="https://github.com/user-attachments/assets/6c9a56bf-1565-4b03-aa85-9c27f241b956" /> --- <sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>

bsakaguchi added the

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2026-10-18 21:12:58 +00:00