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Filename Latest commit message Latest commit date
Radoslav Dimitrov 7a6d1bc30a
 fix(cargo): harden README fetch, clarify status handling, strengthen tests (#1330) 
Follow-up to #1207, addressing items from the cargo validator review.
**Scoped to cargo + shared helpers — no behavior change for existing
npm/pypi/nuget/oci/mcpb publishers.** Safe to merge and promote.

### Changes
**SSRF hardening of the two-call README retrieval**
- Pin the step-2 README URL to an allowed host (`static.crates.io` in
prod; the base host under test) *before* fetching, so a metadata
response can't steer the validator at an internal/attacker host.
- `CheckRedirect` policy pins every redirect hop to the same allowlist
(the initial URL being pinned isn't enough if an upstream 3xx is
followed).
- Cap the README body with `io.LimitReader` (5 MiB).

> Not publisher-exploitable today (the URL comes from crates.io), so
this is defense-in-depth — but it makes the "host is pinned" guarantee
hold in code rather than rely on crates.io's behavior.

**Clearer status handling** (previously any non-5xx/non-200 collapsed to
"not found")
- **429** → reported as transient/retryable, at both the metadata and
README steps.
- **403** → disambiguated via the crate-version endpoint:
genuinely-missing stays "not found"; *exists-but-no-README* gets an
actionable "add a README with `mcp-name` and republish" message (mirrors
the NuGet validator). This continues the 5xx-vs-403 diagnostic split
@P4ST4S started in the #1207 review — thanks!

**Shared `containsMCPNameToken` helper**
Boundary-anchored ownership-token match (prevents prefix confusion, e.g.
a README declaring `io.github.acme/widget-pro` satisfying a claim for
`io.github.acme/widget`), used here **by the cargo validator only**.
Adopting it in PyPI/NuGet is a separate follow-up because it's a
behavior change for those already-live registries.

**Tests & docs**
Hermetic positive `ServerNameFormats`; combined fixture gains a
version-existence endpoint + cases for 403-missing vs 403-no-README,
429, and prefix-confusion rejection; new foreign-README-host (SSRF)
test; internal test for the helper. Docs: list `crates.io` in the
registry-requirements list + the `Package` model doc.

### Testing
`go build`, `go vet`, full `./internal/validators/...` suite (incl. live
cargo positive), `make check-schema`, `validate-examples` all pass. No
new `golangci-lint` findings.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-04 17:34:54 -04:00
..
administration Add registry maintainer onboarding documentation (#820) 2025-12-08 13:43:37 +00:00
contributing update schema url point to the actual location (#884) 2026-02-10 13:32:58 -08:00
design update schema url point to the actual location (#884) 2026-02-10 13:32:58 -08:00
modelcontextprotocol-io feat: add cargo (crates.io) as a package registry type (#1207) 2026-06-03 10:56:43 -04:00
reference fix(cargo): harden README fetch, clarify status handling, strengthen tests (#1330) 2026-06-04 17:34:54 -04:00
community-projects.md docs: add ToolHive Registry Server to community projects (#1261) 2026-05-07 10:36:03 -04:00
README.md docs: fix broken links in Documentation Index (#822) 2025-12-08 13:43:16 +00:00

README.md

MCP Registry Documentation

The MCP registry provides MCP clients with a list of MCP servers, like an app store for MCP servers.

I want to...

Documentation Index