marketplace/cli/internal/cmd/AGENTS.md

# AGENTS.md — internal/cmd

**The command tree: flags, receipts, exit codes.** The only package that may import
every layer below it, and the only one that prints.

`cmd/kettle` is four lines around `cmd.Main(os.Args[1:])` — everything a `main`
usually accumulates lives here instead, because a `main` package cannot be imported
and therefore cannot be tested.

## Commands are values

Each command is one `register(&Command{…})` in an `init()`, carrying the metadata a
human needs — `Short`, `Long`, `Examples`, `Args`, `Group` — **in the same struct
that carries the code**. That is what lets the plugin's SKILL.md files be generated
from this list: a command whose flags changed cannot ship with documentation that
says otherwise.

```go
func init() {
	register(&Command{
		Name:  "tree",
		Group: GroupIssue,
		Args:  "[<id>…]",
		Short: "draw the dependency graph of the local store",
		Long:  `…`,
		Examples: []Example{{"kettle tree", "every root (nothing depends on it)"}},
		Setup: func(fs *flag.FlagSet) func([]string) error {
			out := storeFlag(fs)
			depth := fs.Int("depth", 6, "maximum depth")
			return func(args []string) error { … }
		},
	})
}
```

**`Setup` registers flags and returns the runner**, closing over them. Splitting it
that way is what lets `Command.Flags()` walk a command's flags without running
anything — which is how the doc generator reads them.

**The tree is flat.** `kettle new`, not `kettle issue new`: an agent pays for every
token of every invocation, and the grouping that matters for reading is carried in
`Group` and only shows up in the docs. Three groups, in presentation order:
`project`, `issue`, `sync`.

| file | what is in it |
|---|---|
| `command.go` | `Command`, the registry, `Main`, help rendering, `SilentError`, `Fail`, and `permute` |
| `flags.go` | `storeFlag`/`storeRoot`, `wasSet`, the repeatable `stringList` |
| `sync.go` | `syncStart`/`syncStartExisting`, `commentsSidecarPath` — the shared opening of every tracker command |
| `gen.go` | `kettle gen skills`: the generated region in the plugin's SKILL.md files |
| `init.go` `auth.go` `config.go` `version.go` | group `project`. `version.go` also holds `Version`, the string a release build stamps in with `-ldflags -X` |
| `new.go` `check.go` `ac.go` `tree.go` `index.go` `evict.go` | group `issue` — no network in any of them |
| `pull.go` `push.go` `remote.go` `comment.go` `close.go` `labels.go` `evict_sync.go` | group `sync` |
| `cli_test.go` | builds the binary in `TestMain`, runs it as a subprocess |
| `sync_pull_test.go` `sync_write_test.go` | the tracker halves, against fake servers |
| `gen_test.go` | the generator: determinism, the region splice, the missing-marker refusal |

## Three conventions every command follows

**Flags may come after positionals.** The standard `flag` package stops parsing at
the first non-flag argument, so `kettle ac <id> --check 3` would hand `--check` to
the command as a positional and tick nothing. `permute` moves flags forward, using
the `FlagSet` to know whether a flag swallows the next argument; `--` ends the
permutation. Every other CLI an operator uses interleaves the two, and a tool that
silently ignores a flag because of where it was typed is worse than one that rejects
it.

**Exit codes are three.** `0` fine, `2` for a usage problem (unknown command,
unparseable flags), `1` for an ordinary failure — printed as `kettle <name>: <err>`
by `Main`, which is why no command prefixes its own errors. `SilentError{Code: 1}`
is for a command that has already said everything it has to say: `check` and
`gen --check` use it, because findings went to stdout and a second copy on stderr
would be noise.

**The store is resolved before a socket is opened.** `syncStart` does that in one
place: a command that dialled first would report a network problem for a project
that was never initialized, and an operator would go looking at the wrong thing.
`syncStartExisting` adds `RequireStore` for the commands that read the store rather
than create it — `push`, `comment`, `close`, `sync-evict` — because a missing store
is a mistake to report, not a directory to conjure.

**There is no `--login` and no `--repo`** on any sync command bar `labels`. Which
login a project runs under is a fact about the project, stated once by
`kettle init`. That the two could disagree is what the Python version needed a
`PreToolUse` hook to police.

`--out` is the one flag almost every command has, and an explicit one is used
**exactly as typed**: a relative `--out` stays relative to the working directory,
because that is what the operator asked for.

## Usage

```bash
kettle help                     # the tree, grouped
kettle help push                # one command in full: flags, defaults, examples

kettle init --login noodles --repo owner/name
kettle new --type task --title "Wire sqlc into the appclick repo layer"
kettle ac wire-sqlc-appclick --check 3
kettle check --strict           # exit 1 on any error; --strict counts warnings too

kettle pull 42                  # the issue and everything blocking it, any state
kettle push --update wire-sqlc-appclick
kettle sync-evict --dry-run
```

Every command's own `Long` text is the reference — it is what
`kettle help <name>` prints and what the generator writes into the plugin. **Do not
restate a flag table here**; it would be a third copy of something already in two
places, one of them mechanically checked.

## push and pull, the two halves of one rule

The rule is that **the store holds what has not left this machine.** Both halves are
worth reading in full before either file is touched.

`push` (`push.go`) deletes `<id>.md` and every sidecar under that slug — on create
and on `--update` alike, one rule with no exception, because a `PATCH` is a push and
two rules would put back exactly the question this removes ("is my copy the fresh
one?"). The deletion is the **last** thing that happens, and only after all three of:

1. the call came back without an error and with a 2xx,
2. the answer carries a plausible number — on `--update`, the very number that was
   `PATCH`ed,
3. the number → slug ledger has been written.

Network down, non-2xx, an answer that does not confirm the write: the file stays and
the run stops. Get the ordering wrong and a slug is lost at exactly the moment the
local copy stops being the record, which is why the ledger is written *before*
anything is deleted. A never-pushed `origin: local` issue is never touched by any of
it.

Dependencies go first, in topological order, so a blocker has its number before the
issue that names it. An `--update` can take one extra request with it, because
Gitea's edit endpoint carries no labels — when the answer's label set and the
issue's disagree the whole set goes up in a `PUT`, and a warning on stderr says
which names moved.

`pull` (`pull.go`) is how a pushed issue comes back. Three sources answer "what is
this issue called here", in this order: the ledger (the only one that knows what is
on disk *right now*, so it wins), the `<!-- kettle:id … -->` marker in the
tracker-side body, then the slugified title. A marker is taken at its word only when
the slug is free; a name already in use is a collision, not an identity, and is
uniquified.

Two ways to name what to pull, and they are **not the same operation**: a key is an
*address* and fetches an issue in any state, while a filter is a *query* and leaves
closed issues out. `--limit` is on the **write**, not the selection — it counts what
lands in the store, which is why a filtered pull can enumerate far more than it
keeps and says so. Blockers come down too, recursively to `--depth`, and are outside
the limit: a blocker is followed because a stored issue named it. A pull **overwrites
the body** — it is a fetch, not a merge — with checkbox state the one exception.

## The generator

`gen.go` writes the plugin's SKILL.md command reference from this registry.

**It owns a region, not a file.** Everything between `<!-- kettle:gen -->` and
`<!-- /kettle:gen -->` is replaced on every run; every byte outside comes back
exactly as it was, which matters most for `description:`, the prose that decides
whether an agent loads the skill at all and the one thing here no generator can
write. A file with **no** markers is reported and left alone, never overwritten —
clobbering somebody's prose because they forgot a marker is the failure this design
exists to prevent.

The output is deterministic to the byte — no timestamps, no map iteration — so
regenerating something unchanged produces no diff. `--check` is that property made
useful: it writes nothing and exits 1 when anything on disk differs, which is what a
pre-commit hook or a CI step calls, and it wins over `--dry-run`.

One file per **group**, so adding a group here adds a skill directory over there;
name one only when it is a subject somebody would load on its own. A command with no
`Group` is in no skill and the run says so. A `Long` or `Example` that spells a
region marker out in full is a hard error — the generated block would end inside
itself.

## Keeping this file true

- **Scope:** the shape of the command tree — the registry, the shared helpers, the
  three conventions, the round trip, the generator. The file table names every
  source file in this directory.
- **Update it when** a command file is added or removed, a group is added, a shared
  helper in `flags.go`/`sync.go` changes, an exit code gains a meaning, or the
  push/pull ordering guarantees change.
- **Do not** copy a flag list or a command's `Long` text here. `kettle help <name>`
  and the generated SKILL.md blocks are the two places that exist for it, and a
  third would be the one that drifts.