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JWT Tools

Decode JWTs without verifying, flag risky algorithms and claims, verify HS256 or RS256 with a key.

Connector by basitalisandhu · GitHub account verified by the MCP Registry

IndexedMITLocal (stdio)★ 1
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Works with Claude Code, Codex, VS Code, Cursor, Windsurf, Claude Desktop. Read the repository before you give any tool access to your data.

npx agentmarket install connector/basitalisandhu-mcp-jwt-tools

Asks which of your tools to add it to (Claude Code, Codex, Cursor, VS Code, Windsurf, Gemini CLI, Claude Desktop) and shows the change first. See https://agentmart.dev/cli.

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About

Decode JWTs without verifying, flag risky algorithms and claims, verify HS256 or RS256 with a key.

Reviews

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Permissions

What this server can do and what it asks for, from its tool list, install config and code. Checked Oct 26, 2026.

Tools
3 read · 0 write · 0 deleteRead-only
Secrets
None asked for
Install scripts
None found
Runs as
Docker image

Tools by what they do 3

Read from the source code; the running server may list different tools.

Read 3 · Look things up without changing anything.

  • decode_jwt
  • sign_test_jwt
  • verify_jwt

Network hosts it talks to 2

  • basitalisandhu.github.io · found in code
  • github.com · found in code

Tools (3)

Read from the source code; the running server may differ. Descriptions are the server’s own words; hidden characters are shown as [U+…].

  • decode_jwtDecode a JWT without verifying itread-only

    Base64url-decode the header and payload of a JWS compact token and report findings. The signature is NOT verified; the output says so and the claims must be treated as unverified. Findings cover: alg none or missing, empty signature, jku/x5u/jwk in the header, expired, not yet valid, missing exp/iat/aud/iss/sub/jti, lifetime above max_ttl_hours (default 24), timestamps given in milliseconds, and claims whose names suggest secrets. Timestamps are also returned as ISO 8601. JWE (encrypted, five-part) tokens are rejected.

  • sign_test_jwtSign a JWT for test fixturesread-only

    Create a signed JWS compact token from a claims object for use in tests and local development. iat is set to now unless the payload supplies one; exp is set from expires_in_seconds when given. HS* algorithms use key as the shared secret; RS* algorithms need a PEM private key. Returns the token and the final header and claims.

  • verify_jwtVerify a JWT signature and claimsread-only

    Verify the signature of a JWS compact token with the supplied key for exactly the given algorithm, then check exp (required), nbf, and optionally aud and iss. HS256/HS384/HS512 take the shared secret as key; RS256/RS384/RS512 take a PEM public key, certificate or private key. A token whose header alg differs from algorithm fails without any cryptographic check, which blocks algorithm-confusion attacks. Returns valid (both signature and claims), signature_valid, claims_valid and the reasons.

Signals

Stars
1
Forks
3
Open issues
5
Last commit (this folder)
Oct 18, 2026 (10 days ago)
Last release
Oct 18, 2026 (10 days ago)

From GitHub (fetched Oct 24, 2026).

Details

Registry name
io.github.basitalisandhu/mcp-jwt-tools
Version
0.2.2
Auth
No auth
Packages
oci ghcr.io/basitalisandhu/mcp-jwt-tools:0.2.2
License
MIT
Repository
github.com/basitalisandhu/dev-mcp-servers
Website
basitalisandhu.github.io/dev-mcp-servers/
First seen
Oct 24, 2026
Last checked
Oct 25, 2026
Source
Official MCP Registrygithub-graphql

More from basitalisandhu

Cite this page

JWT Tools MCP server. Agent Mart. https://agentmart.dev/connectors/basitalisandhu-mcp-jwt-tools (last updated 2026-10-25)