
Razi Dev Utilities
Developer utilities over MCP: Base64 encode and decode, decode JWTs, format JSON, do percentages.
What it can do
What data it sees
Do you need an account
An API key from the service settings is required
Developer utilities over MCP: Base64 encode and decode, decode JWTs, format JSON, do percentages.
How to connect
How to connect Razi Dev Utilities to Claude
The server address to paste into Claude settings:
https://www.razi.pro/api/mcp/dev
- Open Claude (claude.ai or the desktop app).
- Go to Settings → Connectors.
- Click Add custom connector.
- Paste the server address copied below into Remote MCP server URL and click Add.
- In a chat, click + → Connectors and switch the new connector on.
Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.
Authorization
After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.
How to connect Razi Dev Utilities to ChatGPT
The server address to paste into ChatGPT settings:
https://www.razi.pro/api/mcp/dev
- Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
- Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
- Open Settings → Connectors and click Create.
- Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
- Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
- In a new chat open + → Apps/Connectors and enable the connector.
OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.
Authorization
On first use ChatGPT opens the service's sign-in window. Sign in and approve access.
How to connect Razi Dev Utilities to Cursor
The server address to paste into Cursor settings:
https://www.razi.pro/api/mcp/dev
Fastest: click Open in Cursor below and confirm the prompt.
Manually:
- In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
- Paste the JSON copied below into
~/.cursor/mcp.json(per project:.cursor/mcp.jsonin the repo root). - Save the file. The server appears in the MCP list; authorize it there if asked.
Authorization
If the service needs sign-in, an authorize button appears next to the server in the MCP list.
Server tool list (5)
Raw names from tools/list. Only developers need these.
| encode_base64 | Encode UTF-8 text as standard Base64 (padded, A-Z a-z 0-9 + /), for embedding binary-unsafe content in JSON, data URIs, HTTP headers or Basic auth. Returns JSON { encoded }. The output uses the standard alphabet, so it is NOT URL-safe: '+' and '/' must still be percent-escaped before they go in a query string or path segment, and this tool does not do that. It is an encoding, not encryption — anyone can reverse it with decode_base64. Runs locally, no size limit beyond the request body. |
| decode_base64 | Decode a Base64 string back to UTF-8 text. Returns JSON { decoded }. Input is verified by re-encoding, so anything that is not genuine Base64 is rejected with an error instead of returning plausible garbage; binary payloads that are not valid UTF-8 will also fail. It handles Base64 and nothing else: a string of %20-style percent escapes is not Base64 and will be rejected rather than unescaped. For a JWT use decode_jwt, which splits the three segments and handles their base64url padding for you. |
| decode_jwt | Decode a JWT's header and payload for inspection. Returns JSON { header, payload, signatureVerified, note, expiresAt, isExpired } — structured objects, not a rendered table. The signature is NEVER verified: that needs the issuer's key, which this service does not have, so signatureVerified is always false and the claims must be treated as untrusted, attacker-controllable input. Expiry is computed from the `exp` claim and is null when the token has none. Use decode_base64 for a bare Base64 string; this tool additionally splits the three segments and handles base64url padding. |
| format_json | Validate and re-print a JSON string. Returns JSON { valid, formatted, minified } — the indented form and the whitespace-free form as plain strings, with no syntax highlighting or colour. Invalid JSON is rejected with the parser's own error message rather than returned as valid:false, so a successful call is proof the input parses. Round-tripping through the parser normalises the document: key order is kept but comments, trailing commas and duplicate keys are lost, and large integers lose precision. |
| calculate_percentage | Run one of four percentage calculations on two numbers. Returns JSON { operation, result } (plus unit: 'percent' for the 'change' operation). The meaning of value1 and value2 depends on the operation, so read their descriptions before calling. Exact arithmetic, no model involved, no rounding applied. Ratios and general expressions are not supported. |