> For the complete documentation index, see [llms.txt](https://agent-marketplace-kit.gitbook.io/agkit-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://agent-marketplace-kit.gitbook.io/agkit-docs/command-reference/build.md).

# agkit build

Generate the committed registries that **tier-2** agents (OpenAI Codex, Cursor) install from, derived from the canonical catalog. Native agents (Claude Code, GitHub Copilot) need no build.

```bash
agkit build [options]
```

## Options

| Option            | Description                                                                                     |
| ----------------- | ----------------------------------------------------------------------------------------------- |
| `--target <list>` | Comma-separated tier-2 targets to build. Default: the tier-2 targets in `metadata.targets`.     |
| `--check`         | Verify generated artifacts are up to date; **non-zero exit on drift** (for CI). Writes nothing. |

Buildable targets: `codex`, `cursor`. Other ids are ignored with a warning.

## What it generates

**Codex** (`codex`):

```
.agents/plugins/marketplace.json                 # registry: object sources { source:"local", path }, policy, category
plugins/<name>/.codex-plugin/plugin.json         # per-plugin manifest mirror
```

**Cursor** (`cursor`):

```
.cursor-plugin/marketplace.json                  # registry: string sources, same shape as the Claude catalog
plugins/<name>/.cursor-plugin/plugin.json        # per-plugin manifest mirror
```

Both derive entirely from `.claude-plugin/marketplace.json` and each plugin's `.claude-plugin/plugin.json`. **Commit the generated files** so consumers can install.

## Behavior

* With no `--target`, builds the tier-2 targets recorded in `metadata.targets`. If there are none, it prints a hint and does nothing.
* Generation is **opt-in**: run `agkit build` once to enable a target. After the first build, [`agkit add`](/agkit-docs/command-reference/add.md), [`agkit bump`](/agkit-docs/command-reference/bump.md), and [`agkit sync`](/agkit-docs/command-reference/sync.md) refresh the already-built registries automatically, so they never drift.
* `--check` compares the on-disk files to what would be generated and reports `missing:` / `stale:` paths, exiting non-zero if any differ — the generated CI workflows run this.

## Examples

```bash
agkit build                          # build the targets in metadata.targets
agkit build --target codex,cursor    # build specific targets
agkit build --check                  # CI gate: fail if a committed registry is stale
```

## See also

* [Target agents](/agkit-docs/reference/target-agents.md) · [`agkit sync`](/agkit-docs/command-reference/sync.md) · [`agkit validate`](/agkit-docs/command-reference/validate.md)