The AI-native knowledge base for ChatGPT

ChatGPT forgets between chats. Hjarni gives it the notes, decisions, and project history it needs to actually help.

Free to start. No credit card required.

What this unlocks

Workflows that actually use your context

Skip the re-onboarding paragraph

Stop pasting 'I run a startup that does X, our stack is Y, our customer is Z' into every new conversation. Save it as one note in Hjarni and ChatGPT reads it on demand.

Draft Monday's plan from last week's notes

Ask ChatGPT to search your Hjarni inbox for the last seven days and draft a weekly plan grouped by project. It uses what you actually wrote, not what it imagines you did.

Save research without breaking flow

Paste an article URL or a quote into the chat. Tell ChatGPT to save it as a Hjarni note, tagged 'research', placed in the right folder, with a one-line summary on top.

Brief a new collaborator from scratch

Tell ChatGPT to summarize a Hjarni folder for someone joining the project. It pulls the active notes, skips the archive, and produces an onboarding brief in the voice you set in folder instructions.

Replace a Custom GPT's knowledge files

If you built a Custom GPT and keep re-uploading the source files when notes change, drop the uploads. Point the GPT at Hjarni instead and it reads the live notes on every conversation.

Setup

Connect ChatGPT in about two minutes

1
Sign up for Hjarni and write a few notes you would want ChatGPT to read.
2
In ChatGPT, open Settings then Apps. Or go straight to the ChatGPT Apps Directory and search for Hjarni.
3
Click Connect on the Hjarni app, or in developer mode create a new app pointing at https://hjarni.com/mcp with OAuth.
4
Sign in to Hjarni when redirected. ChatGPT stores the OAuth token, not your password.
5
In a chat, click the plus icon, enable the Hjarni connector, and ask it to list your recent notes.

Form values for ChatGPT (Apps Directory or developer mode, no JSON file)

Name:                hjarni
MCP Server URL:      https://hjarni.com/mcp
Authentication:      OAuth

The Hjarni MCP endpoint is https://hjarni.com/mcp. The connection uses OAuth, so you sign in with your Hjarni account when prompted. No API key files to manage.

Why Hjarni instead of Custom GPTs or ChatGPT memory

Custom GPTs with knowledge files were the old workaround. They snapshot a moment in time and go stale the second you edit a note. Hjarni keeps the notes live, so ChatGPT reads the current version on every question, including the edit you made five minutes ago.

ChatGPT's built-in memory is good for short, personal facts that the model decides to remember. Hjarni is for the larger surface: actual notes, decisions, and source material that you write deliberately, organize into folders, and edit when reality changes. The two are complementary, not competing.

ChatGPT Projects scope a thread to a workspace. Hjarni works across projects: the same knowledge base shows up in a Projects thread, a regular chat, and Claude or Cursor over MCP. You write notes once and every interface reads them.

Common questions

Questions before you connect ChatGPT

Does Hjarni store my notes inside ChatGPT?

No. Notes live in Hjarni. ChatGPT only reads them through MCP during a conversation, and only after you authorize the connection. Revoking it is a one-click action in ChatGPT settings.

Which ChatGPT plans support the Hjarni connector?

Custom MCP connectors require a paid ChatGPT plan. OpenAI updates the plan-by-plan availability frequently, so check ChatGPT's current connector docs for the latest matrix. Free ChatGPT does not include custom MCP connectors at time of writing.

What can ChatGPT do that it cannot do with file uploads?

Uploaded files go stale the moment you change them. Hjarni gives ChatGPT a live connection to your notes, so updates show up in the next conversation without re-uploading anything.

Does ChatGPT have to search every time?

Yes. ChatGPT does not have a private cache of your notes. Every relevant note is fetched through MCP search at the moment it is needed. That is why the notes are always the source of truth.

Can ChatGPT write to Hjarni, not just read?

Yes. ChatGPT can create notes, update existing ones, add tags, and place notes into folders. You can constrain that behavior with folder-level AI instructions.

Give ChatGPT a memory

Write notes once. ChatGPT reads them across every conversation.

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More integrations

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Write once. You both remember.

Free to start. No credit card required.

Give your AI a memory

Works with Claude and ChatGPT today. Gemini coming soon.