MCLI Client Compatibility Notes

mcli is Silo’s build of the MinIO Client (mc). This page records where the two are interchangeable and where they differ.

pgsty/mc forked from the upstream minio/mc at its final commit, 77f82e18 (2025-11-06). The upstream repository was archived in July 2026 without ever cutting a release that contains that commit — so every mcli release is strictly newer than any official mc binary ever published. Fork releases to date: 20260313, 20260321, 20260417, 20260804, and 20260806.

Principles

The fork follows one rule: the shipped artifact and its channels are renamed; the tool you use is not.

• Renamed / replaced — the artifact name on disk (mcli), the product identity in --version and --help, the distribution channels (GitHub pgsty/mc, the Pigsty repository, docker.io/pgsty/mc), and the signing keys. Not the command syntax, and — depending on how you install it — not even the name you type.
• Unchanged — every command, subcommand, and flag; S3 and admin API behavior, request signing, and protocol headers (x-minio-*); JSON output schemas; exit codes of normal operations; the configuration file format and alias semantics; MC_* environment variables (including MC_HOST_<alias>); the .part.minio resume suffix; and the Go module path github.com/minio/mc.
• Severed — every connection to MinIO-operated services: the release/update feed, the SUBNET support and licensing portal, telemetry, and the pre-seeded play demo alias. Affected commands remain in the CLI for script compatibility and fail with a stable error rather than disappearing.
• Preserved — upstream copyright and the AGPL-3.0 license. Runtime output credits both MinIO, Inc. and PGSTY.

A configuration written by upstream mc is readable by mcli unchanged, and vice versa; both clients can talk to MinIO servers, Silo servers, and any other S3-compatible endpoint.

What changed

Ordered by how likely each change is to affect you, most likely first.

1. The name — what you type, and where the config lives

For many users nothing changes here: the container image keeps mc as its entrypoint, and a binary installed under the name mc behaves identically to upstream. What changed is what we ship — archives and Linux packages install the binary as /usr/local/bin/mcli (package name mcli).

Neither name is hardcoded anywhere. Since 2016 the upstream client has derived its runtime identity from the name it is invoked as, and mcli is the exact rename upstream’s own CONFLICT.md recommended (issue #873) for the Midnight Commander clash — this fork merely promoted that suggestion to the official shipping name, with zero code changes. What that mechanism means in practice:

The one real trap: run mcli for the first time and your existing mc aliases are not there — it starts from an empty ~/.mcli. Either keep invoking it as mc (a symlink suffices — argv[0] is what counts), or copy the state once with cp -a ~/.mc ~/.mcli. For automation and configuration templates, set MC_CONFIG_DIR explicitly: the environment prefix does not follow the name, so one template serves both. Details in Migration.

Get it from GitHub Releases (SHA-256 mcli_<version>_checksums.txt), the Pigsty repository (RPMs GPG-signed, key fingerprint 9592A7BC7A682E7333376E09E7935D8DB9BD8B20), or docker.io/pgsty/mc. Upstream’s minisign key does not sign these artifacts, and dl.min.io is never contacted. Release tags (RELEASE.YYYY-MM-DDTHH-MM-SSZ) and package versions (YYYYMMDDHHMMSS.0.0) keep their upstream schemes.

2. mcli update always fails — on purpose

Self-update is removed. mcli update never contacts the network and never replaces its binary; it prints an explicit notice and always exits 1. Upstream mc update exited 0 when already current, so any cron job or script that calls it and treats a non-zero exit as failure will start failing — drop the call and upgrade through your package manager or GitHub Releases instead. The per-invocation version probe against upstream release feeds is also gone, and MC_UPDATE / MINIO_UPDATE are no longer consulted.

(mcli admin update ALIAS — updating the server — still exists, but Silo servers reject in-place updates server-side.)

3. SUBNET, licensing, and telemetry commands

Everything that reached MinIO SUBNET is disabled at build time. Affected commands keep their names and flags, print a stable notice — “MinIO SUBNET services (registration, licensing, uploads) are disabled in this Silo build of mc; diagnostics remain available locally.” — and exit 1:

The diagnostics themselves stay: mcli support diag / perf / profile / inspect always run in local (airgap) mode — results are written to local files, nothing is uploaded, and SUBNET registration is no longer a prerequisite. Two related hardening changes: inspect no longer falls back to encrypting output with an embedded MinIO public key (your archives stay decryptable by you), and since 20260804 --debug output redacts SUBNET credentials — if you ever shared debug logs from older builds, rotate the keys in them. mcli license info and unregister work locally.

4. The play demo alias is no longer pre-seeded

Fresh configurations seed local, s3, and gcs — not play. Tutorials and smoke scripts that assume the demo alias need it added explicitly: mcli alias set play https://play.min.io <access-key> <secret-key> restores the old behavior, since nothing blocks deliberate access to any S3 endpoint. Existing configuration files are never modified.

5. Output text carries the Silo identity

mcli --version keeps its machine-readable first line and adds an identity line plus dual copyright; --help says “Silo client” and examples use mysilo. Command syntax is untouched — only scripts that grep for upstream identity strings (e.g. “MinIO Client”) need adjusting.

6. For developers

The module path stays github.com/minio/mc, so imports compile unchanged — but go install github.com/minio/mc@latest installs the archived upstream, not this fork. Build from source (git clone https://github.com/pgsty/mc && cd mc && make) or consume it via a replace directive. Contributions need no CLA but require a DCO sign-off (git commit -s). Upstream being archived also means inherited defects are only ever fixed here — most notably minio/mc#5139 (mirror --remove --watch on versioned buckets).

Migration

Moving from an official mc binary to mcli:

1. Install mcli from one of the fork’s channels (see §1 for verification): GitHub Releases archive, yum install mcli / apt install mcli from the Pigsty repository, or docker pull pgsty/mc.
2. Decide what to call it — this determines which configuration it reads:
   • Keep the mc name (least friction): after confirming no upstream binary remains (command -v mc), install it as mc — e.g. ln -s /usr/local/bin/mcli /usr/local/bin/mc. Invoked as mc, it reads your existing ~/.mc untouched; nothing else to migrate.
   • Adopt the mcli name: carry your state over once with cp -a ~/.mc ~/.mcli, or set MC_CONFIG_DIR=~/.mc. Both clients can also coexist side by side, each with its own directory.
3. Clean up automation:
   • remove mc update calls — they now always exit 1;
   • remove license register, support upload, support callhome enable, and support proxy set — same stable failure;
   • support diag / perf / profile / inspect keep working and write local files; drop any step that expected a SUBNET upload;
   • review anything that greps --version output beyond the first line.
4. Re-check play usage in tutorials and smoke scripts (§4).
5. Verify: mcli --version, mcli alias ls, then mcli ls <alias> and mcli ping <alias> against your servers.
6. Rollback stays trivial: the configuration format is identical in both directions, so keeping the old mc binary around lets you switch back at any time.

See also

• Silo vs. MinIO — how the silo server compares to minio