Plugins

CodeAlta plugins are trusted source packages and built-in extensions that can extend the shell, prompt flow, agent runtime, timeline projections, and the in-session alta live tool.

Plugins are for local automation you choose to run. Building a source plugin can execute SDK/NuGet/MSBuild logic, and loading it executes .NET code inside the CodeAlta process.

Install and enable only plugins you trust. Source plugins are built on your machine and loaded into the CodeAlta process, so a plugin has the same practical risk profile as running local code.

Plugin APIs are preview surface area before CodeAlta 1.0. Interfaces, contribution points, service exposure, and behavior can change between 0.x releases; some CodeAlta capabilities may not be exposed yet, and some exposed capabilities may still be incomplete or incorrectly shaped.

Extensibility layers

Plugins are one part of CodeAlta extensibility, not the first tool for every workflow.

Need	Prefer
A repeatable session workflow or mode	Agent prompts
Agent coordination with sessions, asks, notes, reminders, prompts, providers, or skills	Advanced agent workflows
External tools from a standard protocol	MCP servers
Reusable context that does not execute code	Skills from the workspace skills dialog
Host UI, runtime, prompt, timeline, resource, or custom live-tool command extension	Trusted source plugins

Use plugins when you need trusted .NET code loaded into CodeAlta. If a workflow can be expressed as an agent prompt, MCP configuration, or skill package, that path is usually easier to inspect and review.

Built-in plugins

CodeAlta ships trusted built-in plugins through the same plugin runtime used for source plugins:

Plugin	What it adds
GitHub	`#` issue lookup in GitHub repositories and an optional `gh` agent tool when the GitHub CLI is installed.
MCP	Model Context Protocol server configuration, `alta mcp` commands, session-activated MCP agent tools, and the MCP Servers dialog.
Statistics	Transient per-turn/session statistics timeline cards and a `statistics estimate` live-tool command.

Manage plugins

Open plugin management with Ctrl+G Ctrl+N, /plugins, or /plugin.

CodeAlta plugin management dialog with plugin list, diagnostics, and selected plugin contributions — Plugin management keeps discovered plugins, diagnostics, source actions, and contribution summaries visible in one dialog.

The dialog shows:

plugin scope and state;
diagnostics from discovery, config, build, load, activation, contributions, callbacks, source changes, and unload;
contribution summaries;
unknown config entries;
source and README open actions when available.

You can also use a headless status summary:

alta --plugins-status

Source plugins

Dynamic source plugins are discovered from:

~/.alta/plugins/<package-id>/plugin.cs for global plugins;
<project>/.alta/plugins/<package-id>/plugin.cs for project-scoped plugins.

Project-scoped plugins apply only to the matching project. Global plugins apply across workspaces. For source-plugin layout, examples, contribution points, resource roots, prompt editor attachments, alta command integration, and safe authoring guidance, see Plugin development.

Disable or bypass plugins

Source plugins and built-in plugins are enabled by default when discovered. Disable a plugin in TOML when you do not want it built or loaded:

[plugins.HelloWorld]
enabled = false

Built-in plugin IDs are lowercase, for example:

[plugins.github]
enabled = false

[plugins.mcp]
enabled = false

[plugins.statistics]
enabled = false

When a plugin is broken, start CodeAlta with a bypass:

alta --no-plugins
alta --plugin-safe-mode

Or set:

CODEALTA_DISABLE_PLUGINS=1

These bypasses are recognized before plugin-contributed command-line options.