# ToolDurus

> ToolDurus is a platform that gives any large language model real tools over the Model Context Protocol (MCP). Think of it as an app store, but with tools for AI. It offers a growing catalog of tools, a shared file storage that both the user and the model work in, and a built-in chat. Users connect it to Claude, ChatGPT, Le Chat, Grok or their own agents with a personal MCP URL. Made in the EU (Czech Republic). Live at https://app.tooldurus.com

## Mission

- Help build European AI sovereignty: tools built and run by a European company, usable with any model (including European and local ones), keeping users' tools, files and settings independent of any single AI provider.

## Pricing

- Free during early access: payments are not switched on yet, no credit card needed. All tools, the chat, storage and organizations are included. Fair-use limits apply to the built-in chat. Paid plans may come later.

## How it works

1. Sign up with just an email (password can be set later) and verify the email.
2. Switch on the tools you need; dependencies are added automatically. Tools that need credentials (Seznam.cz mailbox, ČÚZK API key) store them encrypted.
3. Get a personal MCP URL: https://tools.tooldurus.com/mcp/<token> (treat it like a password; it can be regenerated).
4. Use the tools in ToolDurus Chat, or add the URL as a custom connector in any MCP client.

## Tool families (current selection; the catalog keeps growing)

- Storage: request_file_upload, store_files (upload widget helper), list_storage, search_storage, manage_storage (rename, move, copy, trash, versions), create_file, request_file_download_link (one-time, 2 h).
- Word: docx_create (blocks, Markdown, templates, mail merge), docx_view (incl. Czech typography check), docx_edit, docx_review (tracked changes and comments), docx_structure, docx_export.
- Excel: xlsx_create, xlsx_view (query, pivot), xlsx_edit, xlsx_structure (join like VLOOKUP), xlsx_export.
- PowerPoint: pptx_create, pptx_view (layout QA), pptx_edit, pptx_structure, pptx_export.
- PDF: pdf_create, pdf_view (forms, QR payments), pdf_edit (true redaction, forms, protect), pdf_structure (merge, split, interleave scans), pdf_export.
- PDF/A: convert_pdf_to_pdfa (1b/2b/3b), verify_pdfa (veraPDF, offline).
- CAD: dxf_create, dxf_view (quantity take-offs), dxf_edit, dxf_structure, dxf_export (PDF to scale, DWG, GeoJSON, STL/OBJ), dwg_dxf_convert, dgn_dxf_convert (MicroStation DGN V8).
- GIS: geo_vector — GDAL-based vector and raster analysis (reproject, buffer, overlay, spatial join, hillshade, contours, viewshed, NDVI, zonal stats, IDW, maps).
- Images: image_view (EXIF, QR/barcodes), image_edit, image_create (QR Platba CZ, SEPA, Wi-Fi, vCard, barcodes, icons), image_convert (incl. HEIC, AVIF).
- Audio and video: audio_view (LUFS), audio_edit, audio_convert, video_edit (trim, 9:16, subtitles, compress, join).
- Email · Seznam.cz: seznam_cz_send_email, seznam_cz_list_emails, seznam_cz_get_email, seznam_cz_reply_forward_email, seznam_cz_move_email, seznam_cz_check_signature.
- Czech cadastre · ČÚZK: cuzk_katastr_lookup (parcels, buildings, units, proceedings; owners are never returned), cuzk_katastr_reference. Requires the user's own ČÚZK API key.
- Other: chart_create, manage_archive (ZIP/TAR with password), search_vector_index (semantic search in file content), get_current_time.

## Storage

- One storage shared by the web file manager, ToolDurus Chat and every connected MCP client.
- 500 MB per account (including versions); up to 50 MB per file in web and chat; 10 MB per batch via the in-chat upload widget in MCP Apps clients.
- 5 previous versions per file with block-level deduplication; deleted files go to a trash only the user can empty.
- Read-only folder (llm_read_only) the model can read but never modify.
- Optional per-chat isolation: each conversation sees only its own files plus the read-only folder.
- Semantic search runs on ToolDurus's own embedding model (multilingual-e5-small), not a third-party API.

## ToolDurus Chat

- Models: Gemini 2.5 Flash (default), Gemini 2.5 Pro (1M-token context), and the user's own local model via Ollama (a script sets up Ollama and a secure tunnel). More providers are planned.
- Fair-use limit in a rolling 12-hour window; up to 8 rounds of tool calls per reply; local models are not counted.

## For developers

- Transport: Streamable HTTP, stateless JSON-RPC; batches up to 50 messages. Protocol version 2025-11-25.
- Endpoint: POST https://tools.tooldurus.com/mcp with `Authorization: Bearer <token>`, or POST https://tools.tooldurus.com/mcp/<token>.
- Results include text and structuredContent. Server card at /.well-known/mcp/server-card. MCP Apps upload widget at ui://files/upload.
- Compact mode exposes two meta tools, tooldurus_tools and tooldurus_call, reducing tool definitions from about 355 tokens per tool to about 4. Large tool families also offer action="help" for detailed docs on demand.
- Versionable tools accept save_as_version_of to overwrite a file as a new version.

## Organizations

- Lockable policies: email sign-in codes (MFA), per-chat isolation, direct attachment access, compact mode.
- Allowlists for tools and chat models; central tool configuration; one local model for all members.
- Shared organization drive with a read-only folder; option to restrict writes to admins.
- Switch external MCP access on or off for members; invitations by email (7 days); multiple admins; remote sign-out of member devices.

## Security and privacy

- Passwords hashed with scrypt; optional email sign-in codes; device list with instant revocation across console and chat.
- External credentials encrypted at rest and never shown again.
- Tool-call logs record only the shape of arguments, never values; tokens are masked in logs; MCP request bodies are not logged.
- Files stored under random paths; zip-bomb and malicious-filename protection.

## FAQ

- **Is it really free?** Yes. We haven’t turned on any payments yet, so the whole platform costs nothing and you don’t need a card to sign up. Paid plans may come later, so this is the best time to jump in. Only the built-in chat has a fair-use limit.
- **What is MCP?** The Model Context Protocol is an open standard for connecting AI apps to tools and data. ToolDurus is an MCP server: any app that supports custom MCP connectors can use its tools.
- **Which AI apps can I connect?** Any MCP-capable client. We have step-by-step guides for Claude, ChatGPT, Le Chat and Grok, and it also works with interfaces like LibreChat and your own agents.
- **Which models run in ToolDurus Chat?** Gemini 2.5 Flash and Gemini 2.5 Pro (with a 1M-token context), plus any local model you pair through Ollama. More providers are on the way. Organizations can limit which models members may pick.
- **How do I run my own local model?** Download a small script from your profile. It starts Ollama, pulls a model (qwen2.5:3b by default), opens a secure tunnel and prints a pairing link you paste back into ToolDurus. Your local model doesn't count towards chat usage limits.
- **How much can I store, and how big can files be?** 500 MB per account, including older versions. Up to 50 MB per file in the web and in the chat. The upload widget inside external AI apps takes up to 10 MB per batch; for larger files the model gives you an upload link.
- **Is there a limit on chat usage?** Yes, a fair-use limit in a rolling 12-hour window, measured in model tokens. A single reply can run up to 8 rounds of tool calls. Local models are not counted.
- **Is my email password safe?** It is encrypted before it is stored and never shown again in the interface. Sending email is rate-limited and repeated failed sign-ins are blocked. We recommend an app-specific password from Seznam.cz.
- **What do I need for the cadastre tools?** Your own key to the ČÚZK “REST API for remote access to cadastral data”. ToolDurus queries parcels, buildings, units and proceedings and converts coordinates between WGS84 and S-JTSK. Owner information is never returned.
- **Can the AI damage my files?** Results are saved as new files by default. When a tool overwrites a file, the previous content becomes a version you can restore, and deletions go to a trash only you can empty. Folders marked read-only can never be changed by a model.
- **What happens if I delete my account?** Your files, versions, conversations and settings are deleted. Technical logs are kept only in anonymised form.

## Guides

- Overview of all guides: https://tooldurus.com/knowledge-base/
- Claude: https://tooldurus.com/knowledge-base/connect-claude-mcp/
- ChatGPT: https://tooldurus.com/knowledge-base/connect-chatgpt-mcp/
- Mistral Le Chat: https://tooldurus.com/knowledge-base/connect-mistral-mcp/
- Grok: https://tooldurus.com/knowledge-base/connect-grok-mcp/
- Full text of all guides for LLMs: https://tooldurus.com/llms-full.txt

## Contact

- info@tooldurus.com (ToolDurus s.r.o.)

## Company and data protection

- Operated by ToolDurus s.r.o., Company ID (IČO) 301 63 234, Větrná 1467/72a, 370 05 České Budějovice, Czech Republic. Registered in the Commercial Register kept by the Regional Court in České Budějovice, Section C, File 37093.
- EU-based company; personal data processed in line with the GDPR. Data minimisation (sign-up with email only, tool-call logs without argument values), right to erasure via account deletion, encrypted credentials, versioned consent to terms and privacy policy.

# Guide contents (full text)

## How to Connect ToolDurus to Claude via MCP (Step by Step)
Source: https://tooldurus.com/knowledge-base/connect-claude-mcp/

Add ToolDurus to Claude as a custom MCP connector, set tool permissions, upload files and convert them right in the chat. Illustrated guide in English and Czech.

### 1. Open Customize in Claude
In Claude, select Customize in the left sidebar.

### 2. Switch to Connectors
Select the Connectors tab at the top of the Customize page.

### 3. Add a custom connector
Click Add in the upper-right corner, then choose Add custom connector.

### 4. Enter your ToolDurus MCP URL
Enter ToolDurus as the connector name and paste your own personal ToolDurus MCP server URL into the URL field. Do not copy the URL shown in the screenshot. Click Continue.
Security warning: Never share your token Your personal ToolDurus MCP URL may contain an access token. Treat the entire URL like a password. Never share it, publish it in screenshots, public chats or repositories. If exposed, revoke or rotate the token in ToolDurus.

### 5. Choose the authentication mode
Claude detects No sign-in for this connector. Keep No sign-in selected, review the warning that anyone with the server URL can use the connector, then click Add. The personal URL must remain private.

### 6. Connect ToolDurus
On the ToolDurus connector page, click Connect.

### 7. Review tool permissions
Once connected, Claude displays ToolDurus tools and their permissions. Review each permission and choose the level of access you are comfortable granting. The screenshot shows Always allow; you do not have to enable it for every tool.

### 8. Upload a file in Claude
Start a new chat and ask Claude to let you upload a file to ToolDurus. Use the upload widget to select or drop your file.

### 9. Run a conversion and download the result
Tell Claude which format you need. In this example, Claude converts a DGN file to DXF and DWG and provides temporary download links. Review any conversion warnings and check the output in your CAD software.

### 10. Start a new conversation
ToolDurus is now available to Claude. Open a new chat and describe the task you want to perform.
Open ToolDurus →

## How to Connect ToolDurus to ChatGPT via MCP (Step by Step)
Source: https://tooldurus.com/knowledge-base/connect-chatgpt-mcp/

Add your ToolDurus MCP URL to ChatGPT as a custom MCP server, confirm access and run a real PDF/A conversion. Illustrated guide in English and Czech.

### 1. Open ChatGPT Plugins
In ChatGPT, open Plugins from the sidebar. Click Add in the upper-right corner and choose Add custom MCP server.

### 2. Configure the MCP server
Fill in the server details. Use your own ToolDurus MCP endpoint, not an endpoint copied from a screenshot or another user.
- Name: ToolDurus
- Description: Platform connecting LLMs with external tools and resources
- Connection: Server URL — paste your personal ToolDurus MCP URL
- Authentication: No authentication
Select No authentication as shown, review the custom MCP server risk warning, tick I understand and want to continue, then click Create as a plugin. Use only your own trusted ToolDurus MCP URL.
Security warning: Never share your token Your personal ToolDurus MCP URL may contain an access token. Treat the entire URL like a password: never share it with anyone, publish it in screenshots, paste it into public chats, or commit it to a repository. Use only your own URL. If it has been exposed, revoke or rotate the token in ToolDurus before using it again. Selecting ‘No authentication’ in ChatGPT does not make the token in the URL public or safe to share.

### 3. Confirm the ToolDurus connection
ChatGPT may show a connection confirmation. Review the data-sharing notice and click Connect ToolDurus to proceed. The server configuration shown above uses No authentication, not OAuth. Only connect servers you trust.

### 4. Check that the plugin is connected
Once the connection succeeds, ChatGPT shows a confirmation and ToolDurus appears under Installed. You can now use its available tools from the chat.

### 5. Try a real workflow: PDF/A validation
For example, ask ChatGPT to open ToolDurus and provide a file-upload interface. Upload a PDF, then request a PDF/A compliance check, conversion if needed and a second validation.
Example prompt Check the PDF/A compliance of my uploaded file. If it fails, convert it to PDF/A and validate the converted file again.

### 6. Retrieve the output file
Ask ChatGPT to generate a download link for the converted file. If the integration supports it, ToolDurus can provide a temporary download URL. Check the expiry time and whether the link is single-use.
Ready to connect your tools?
Open ToolDurus →

## How to Connect ToolDurus to Mistral Le Chat via MCP
Source: https://tooldurus.com/knowledge-base/connect-mistral-mcp/

Set up ToolDurus as a custom connector in Mistral Le Chat, review connector permissions and try an email workflow. Illustrated guide in English and Czech.

### 1. Open Mistral Le Chat
Open Mistral Le Chat in your browser. In the left sidebar, find Context → Connectors.

### 2. Open Connectors
Select Connectors in the sidebar. The page shows your connectors and a New connector button.

### 3. Open the marketplace
Click Browse marketplace to open the connector marketplace.

### 4. Add a custom connector
On the Marketplace page, select New custom connector in the upper-right corner.

### 5. Enter your ToolDurus MCP details
Enter ToolDurus as the connector name. Paste your own personal ToolDurus MCP URL into Server. You can add a description such as “Platform connecting LLMs with external tools and resources”. Choose No Authentication if that is how your personal MCP endpoint is configured, then click Add connector. Never copy the URL from the screenshot.
Security warning: Never share your MCP token Your personal MCP URL may contain an access token. Treat the entire URL like a password. Never publish it in screenshots, public chats, repositories, or share it with anyone. If exposed, revoke or rotate the token in ToolDurus.

### 6. Review available tools and permissions
After adding the connector, review the available ToolDurus tools. Set permissions to match what you want Mistral to be able to do. The screenshot shows Allow; grant access only to tools you trust.

### 7. Try an email task
Start a chat and ask Mistral to send an email using ToolDurus. In this example, the assistant uses the Seznam.cz email tool to send a message asking about MCP server functions. Always review the recipient and message before authorizing actions.

### 8. Find and read the sent email
Ask Mistral to find the sent email and show its full content. In the example, ToolDurus uses email listing and retrieval tools to return the message details.
Open ToolDurus →

## How to Connect ToolDurus to Grok via MCP (Step by Step)
Source: https://tooldurus.com/knowledge-base/connect-grok-mcp/

Add ToolDurus to Grok as a custom connector, then use it for email, ZIP inspection and video editing. Seven illustrated steps in English and Czech.

### 1. Open Grok
Open Grok and locate Plugins in the left sidebar.

### 2. Open the connector catalog
Open Plugins to view available connectors. Choose New Connector.

### 3. Choose a custom connector
In the New Connector dialog, select Custom to add your own MCP server.

### 4. Confirm ToolDurus is connected
Complete the connector setup using your personal ToolDurus MCP server URL from your ToolDurus account. Confirm that ToolDurus appears under Connected with the Added status.

### 5. Test the connector with email
Ask Grok to check the latest received email. In this example, Grok retrieves message metadata and reports a ZIP attachment.

### 6. Inspect a ZIP attachment
Ask what is inside the ZIP. Grok uses ToolDurus tools to inspect the archive and list the contained files.

### 7. Edit a video using ToolDurus
Ask Grok to overlay the image in the upper-right corner of the original video and speed up the video 4×. The example returns an edited MP4 file.
Security note: Use your own ToolDurus MCP URL and review connector permissions before granting access to emails or files.

### Ready to try it?
Open ToolDurus to get your personal MCP endpoint, then connect it in Grok.
Open ToolDurus