How to integrate Hjarni MCP with Codex

Codex is one of the most popular coding harnesses out there. And MCP makes the experience even better. With Hjarni MCP integration, you can draft, triage, summarise emails, and much more, all without leaving the terminal or the app, whichever you prefer.

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Api Key

Hjarni is a personal knowledge management platform for notes, containers, tags, and linked ideas. It helps you keep knowledge organized, searchable, and easier to maintain.

15 Tools

Introduction

Codex is one of the most popular coding harnesses out there. And MCP makes the experience even better. With Hjarni MCP integration, you can draft, triage, summarise emails, and much more, all without leaving the terminal or the app, whichever you prefer.

Also integrate Hjarni with

Why use Composio?

Apart from a managed and hosted MCP server, you will get:

  • CodeAct: A dedicated workbench that allows GPT to write its code to handle complex tool chaining. Reduces to-and-fro with LLMs for frequent tool calling.
  • Large tool responses: Handle them to minimise context rot.
  • Dynamic just-in-time access to 20,000 tools across 1000+ other Apps for cross-app workflows. It loads the tools you need, so GPTs aren't overwhelmed by tools you don't need.

How to install Hjarni MCP in Codex

Run the setup command

Run this command in your terminal to add the Composio MCP server to Codex.

Terminal

It will initiate the authentication in a browser window, authorize Codex to access your Composio account.

Composio authentication page

(Optional) Authenticate with OAuth

To authenticate manually, run the login command to open a browser window and authorize Codex to access your Composio account.

bash
codex mcp login composio

Verify the connection

Run codex mcp list to confirm Composio appears as a registered MCP server.

bash
codex mcp list

Codex App

Codex App follows the same approach as VS Code.

  1. Click ⚙️ on the bottom left → MCP Servers → + Add servers → Streamable HTTP:
  2. Fill the header and Key fields with { "x-consumer-api-key" = "ck_*******" }.
  3. The Key is the Composio API key, that you can find on dashboard.composio.dev
  4. Click on Authenticate and authorize Codex to your Composio account and you're all set.
Codex App MCP setup
  1. Restart and verify if it's there in .codex/config.toml
bash
[mcp_servers.composio]
url = "https://connect.composio.dev/mcp"
http_headers = { "x-consumer-api-key" = "ck_*******" }

What is the Hjarni MCP server, and what's possible with it?

The Hjarni MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Hjarni account. It provides structured and secure access to your notes, containers, and tags, so your agent can create, find, organize, update, and recover knowledge on your behalf.

  • Note creation and editing: Have your agent create one or many Markdown notes, update their content and metadata, and place them in your inbox or chosen containers.
  • Knowledge search and review: Instruct your agent to list and filter active, archived, favorited, or inbox notes, then retrieve a note with its content, tags, attachments, and links.
  • Container organization: Let the agent create root or nested containers and update their names, descriptions, placement, ordering, or AI instructions.
  • Tag management: Direct your agent to create and rename tags, list available tags, and review how many notes use each one.
  • Trash and account oversight: Have your agent move notes to recoverable Trash, review trashed notes and purge dates, restore notes, or check account usage and quotas.

Conclusion

You've successfully integrated Hjarni with Codex using Composio's MCP server. Now you can interact with Hjarni directly from your terminal, VS Code, or the Codex App using natural language commands.

Key benefits of this setup:

  • Seamless integration across CLI, VS Code, and standalone app
  • Natural language commands for Hjarni operations
  • Managed authentication through Composio
  • Access to 20,000+ tools across 1000+ apps for cross-app workflows
  • CodeAct workbench for complex tool chaining

Next steps:

  • Try asking Codex to perform various Hjarni operations
  • Explore cross-app workflows by connecting more toolkits
  • Build automation scripts that leverage Codex's AI capabilities
TOOLS

Supported Tools

Every Hjarni action and event your agent gets out of the box.

Create Container

Create a root or nested Hjarni container for organizing notes.

Create Note

Create a Markdown note in the inbox or a container.

Create Notes

Create 1-25 Markdown notes in order and return one result per input.

Create Tag

Create a Hjarni tag for organizing notes.

Get Account Status

Return the connected Hjarni identity, token scope, plan, teams, and current resource usage and quotas.

Get Note

Get one Hjarni note by ID with its Markdown body, tags, container, attachments, links, and optimistic-lock version.

List Containers

List Hjarni containers as active roots, archived roots, or all active containers in a flat view.

List Notes

List and filter personal Hjarni notes, including active, inbox, archived, or favorited notes.

List Tags

List all Hjarni tags and their note counts.

List Trashed Notes

List recoverable trashed Hjarni notes with their deletion and scheduled purge times.

Rename Tag

Rename an existing Hjarni tag without changing its note associations.

Restore Note

Restore a note from Trash before its scheduled purge and return the active note.

Move Note to Trash

Move a note to recoverable Trash.

Update Container

Update a Hjarni container's name, description, parent, position, or container-specific AI instructions.

Update Note

Update note metadata, placement, tags, or body.

FAQ

Frequently asked questions

With a standalone Hjarni MCP server, the agents and LLMs can only access a fixed set of Hjarni tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Hjarni and many other apps based on the task at hand, all through a single MCP endpoint.

Yes, you can. Codex fully supports MCP integration. You get structured tool calling, message history handling, and model orchestration while Tool Router takes care of discovering and serving the right Hjarni tools.

Yes, absolutely. You can configure which Hjarni scopes and actions are allowed when connecting your account to Composio. You can also bring your own OAuth credentials or API configuration so you keep full control over what the agent can do.

All sensitive data such as tokens, keys, and configuration is fully encrypted at rest and in transit. Composio is SOC 2 Type 2 compliant and follows strict security practices so your Hjarni data and credentials are handled as safely as possible.

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