mcpp-index is the default package index for mcpp: one pkgs/<initial>/<name>.lua descriptor per package. Browse it online at https://mcpplibs.github.io/mcpp-index/.

Two kinds of packages live there:

• Native mcpp module libraries (mcpplibs.*, nlohmann.json, imgui, opencv, …) — the upstream repository carries its own mcpp.toml, so the descriptor (Form A) declares only metadata and a download address. A library built from this template is Form A.
• Third-party C/C++ libraries under the compat namespace — upstream has no mcpp support, so the descriptor (Form B) inlines the build information.

mcpp search <keyword>          # search the index (also refreshes it)
mcpp add <pkg>[@<version>]     # write the dependency into mcpp.toml
mcpp build                     # fetch and build; dependencies propagate along the chain
mcpp index list|add|remove|update   # manage registries

Package identity is a pair: namespace is a dotted hierarchical path, name is a single atomic segment (compat + zlib, mcpplibs.capi + lua — never mcpplibs + capi.lua).

A bare dependency name resolves in exactly three places, in order:

1. mcpplibs — the default namespace
2. compat — third-party C/C++ wrappers
3. packages that declare no namespace at all

Anything else must be spelled out — there is no index-wide fuzzy search by short name:

[dependencies]
"chriskohlhoff.asio" = "1.38.1"     # dotted selector

[dependencies.chriskohlhoff]        # or a namespace sub-table
asio = "1.38.1"

When resolution fails: read the error (it lists the namespaces searched), then check the spelling against the online index, and run xlings update — a release tarball bundles an index snapshot frozen at build time, which is the usual reason a fresh version "does not exist".

Mirrors: mcpp self config --mirror CN switches to the GitCode mirror; GLOBAL (upstream) is the default.

mcpp publish --dry-run      # package a tarball, hash it, print the descriptor, upload nothing
mcpp emit xpkg -o mylib.lua # descriptor only, no packaging

--dry-run prints the remaining steps with the project's real URLs filled in:

1. Tag and push — git tag -a v<version> -m "v<version>" && git push --tags
2. Attach target/dist/<name>-<version>.tar.gz to that GitHub Release
3. Open a PR to mcpp-index adding pkgs/<initial>/<name>.lua

Before opening the PR, confirm [package] in mcpp.toml carries an accurate namespace, name, version, description, license and repo — the descriptor is generated from those fields, and a repo still pointing at the template is the classic mistake.

The index's CI (validate.yml) lints every descriptor, checks the GLOBAL/CN mirror tables, and builds a small test project per package on three platforms. Reproduce the lint locally with mcpp xpkg parse pkgs/<initial>/<name>.lua.

For anything beyond a generated Form A descriptor — a compat wrapper, features, a CN mirror, multiple majors in one package — follow the index's own end-to-end procedure rather than improvising:

• Skill: add-mcpp-index-package
• docs/package-types.md — descriptor templates for the four library shapes
• docs/repository-and-schema.md — layout, schema cheat-sheet, [indices] redirection, CI behavior
• docs/cn-mirror.md — the GitCode CN mirror loop and its fallback
• Chinese versions of all three live under docs/zh/

Upstream mcpp is authoritative for the descriptor field specification; the index docs are authoritative for repository conventions and the contribution flow.