JWT Tools
OCI · GHCR.IO/BASITALISANDHU/MCP-JWT-TOOLS
Decode JWTs without verifying, flag risky algorithms and claims, verify HS256 or RS256 with a key.
Available components
Last scanned (20 hours ago)
Scores higher than 74% of OCI servers
Category Security
How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. How we score → Why this is hard to score →
Supply Chain Security0
- No malware scan is available for this kind of package: the supply-chain vendors we use do not cover it. This is a permanent gap in our coverage, not a finding about the package.Unverified
- Known CVEs could not be checked: this artifact ships no SBOM or dependency manifest, so there is no dependency list to read.Unverified
- Install-script risk not yet assessed.Unverified
- Dependency health could not be checked: this artifact ships no SBOM or dependency manifest, so there is no dependency list to read.Unverified
Provenance & Transparency100
- Source repository is publicly reachable at the declared URL. View diagnostics → Pass
- Cryptographically verified build provenance (signed, bound to basitalisandhu/dev-mcp-servers). View diagnostics → Pass
- Clear OSI-approved license (MIT).Pass
- Actively maintained (last published 2 days ago).Pass
- Publishes a security disclosure policy (SECURITY.md).Pass
Schema Quality & AI Usability65
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 709 tokens (~236/item across 3 items; 3 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management0
- Stability not yet verified: not enough scan history yet (needs a 30-day window).Unverified
Tool Coverage93
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 80% of tool parameters carry a description.Partial
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 3 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 4 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
Unverified: 2 categories
Categories scored 0 because we could not verify them: a data source with nothing on this package, evidence we could not reach, or a check we could not run. We only credit what we can confirm.
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 14 Oct 26 +29
- Injection markers: unverified → pass ▲ security
- First check of Judged manipulation: pass security
- Stability: Stability not yet verified: not enough scan history yet (needs a 30-day window). security
- Tool coverage: unverified → 100 ▲ functional
- MCP protocol: unverified → pass ▲ functional
- First check of Schema quality: fail functional
- First check of Schema quality: excellent functional
- First check of Destructive annotations: pass functional
- First check of Schema quality: fail functional
- First check of Tool coverage: 80 functional
- 13 Oct 26 0
- Package version: 0.2.0 → 0.2.1 functional
- 12 Oct 26 0
- Package version: 0.1.1 → 0.2.0 functional
- 7 Oct 26 20
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 16 Oct 2026 · Analysed oci/ghcr.io/basitalisandhu/mcp-jwt-tools@0.2.1
Provenance Verified
A signed build attestation was found and verified, binding this exact artifact to the source repository it claims to come from.
| Result | Verified |
|---|---|
| Ecosystem | oci |
| Reason | Verified |
| Discovered via | OCI referrers API |
| Source repo | basitalisandhu/dev-mcp-servers |
| Certificate issuer | https://token.actions.githubusercontent.com |
| Certificate SAN | https://github.com/basitalisandhu/dev-mcp-servers/.github/workflows/publish-github-packages.yml@refs/tags/v0.2.1 |
| Rekor log index | 3244679324 |
| Predicate type | SLSA build provenance https://slsa.dev/provenance/v1 |
| Subject digest | sha256:84e3057ceb6a126f458bc014ce5e9b1c5035a731666adbf629955a5b5fbd0c81 |
Background: How many MCP packages publish verified provenance →
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
decode_jwt Decode a JWT without verifying it ~203
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.
| Name | Type | Req | Description |
|---|---|---|---|
| max_ttl_hours | number | – | Lifetime threshold for the long-ttl finding, in hours. Default 24. |
| now | integer | – | Unix seconds to evaluate exp and nbf against. Default: current time. |
| token | string | yes | Compact JWS token (header.payload.signature). A leading 'Bearer ' is ignored. |
No output schema declared.
No examples provided.
sign_test_jwt Sign a JWT for test fixtures ~147
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.
| Name | Type | Req | Description |
|---|---|---|---|
| algorithm | string | yes | – |
| expires_in_seconds | integer | – | – |
| key | string | yes | – |
| now | integer | – | Unix seconds used for iat and exp. Default: current time. |
| payload | object | yes | Claims to sign, for example {"sub":"user-1","aud":"api"}. |
No output schema declared.
No examples provided.
verify_jwt Verify a JWT signature and claims ~242
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.
| Name | Type | Req | Description |
|---|---|---|---|
| algorithm | string | yes | The one algorithm the verifier accepts. |
| audience | string | – | Required aud value (matches a string aud or one element of an array aud). |
| clock_tolerance_seconds | integer | – | Leeway for exp and nbf. Default 0. |
| issuer | string | – | Required iss value. |
| key | string | yes | Shared secret (HS*) or PEM-encoded key (RS*). |
| now | integer | – | Unix seconds for time checks. Default: current time. |
| token | string | yes | Compact JWS token (header.payload.signature). A leading 'Bearer ' is ignored. |
No output schema declared.
No examples provided.
How do I install the JWT Tools MCP server?
JWT Tools runs locally as a container image, launched with docker run --rm -i ghcr.io/basitalisandhu/mcp-jwt-tools:0.2.1. Ready-made configuration for Claude, Cursor, VS Code, Codex and 3 more is on this page, copied from each client's own documentation.
oci · ghcr.io/basitalisandhu/mcp-jwt-tools
claude mcp add basitalisandhu-mcp-jwt-tools -- docker run --rm -i ghcr.io/basitalisandhu/mcp-jwt-tools:0.2.1
What is the JWT Tools MCP server?
JWT Tools is an MCP server listed in the public MCP registry as io.github.basitalisandhu/mcp-jwt-tools. Decode JWTs without verifying, flag risky algorithms and claims, verify HS256 or RS256 with a key. This page covers its container image (ghcr.io/basitalisandhu/mcp-jwt-tools).
Is the JWT Tools MCP server safe to use?
JWT Tools scores 49 out of 100 on VerifyMCP. Its build provenance is signed and verified. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the JWT Tools MCP server expose?
JWT Tools exposes 3 tools: decode_jwt, verify_jwt, sign_test_jwt. Their descriptions and schemas cost roughly 592 tokens of context every time the server is loaded.
Is the JWT Tools MCP server still maintained?
JWT Tools is still listed as active in the MCP registry. We last reached this channel on 16 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.
What licence is the JWT Tools MCP server under?
JWT Tools declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.