abscissa 0.1.0

A safety-aware MCP server for Linear

Abscissa

Abscissa is a Python stdio MCP server for Linear. It turns Linear's GraphQL API into 35 tools for an MCP client: issues, projects, cycles, dependencies, comments, labels, workflow states, teams, and users.

The design priority is deliberate control over project data. Read operations return cursor-paginated results; get_user_issues() resolves the authenticated Linear user; archive and delete tools require an explicit confirm=true before they make a destructive API call. The server stores no credentials and reads LINEAR_API_KEY from its process environment.

Abscissa uses the stdio transport from the Model Context Protocol. Any client that supports stdio MCP can launch it as a local tool process.

Run it

You need Python 3.10+ and a Linear personal API key.

git clone https://github.com/KazKozDev/abscissa.git
cd abscissa
python3 -m venv .venv
.venv/bin/pip install -e '.[dev]'
export LINEAR_API_KEY='lin_api_…'
.venv/bin/abscissa

After the first release, installation will also be available directly from PyPI:

pip install abscissa

The final command starts the MCP server on standard input and output. Register .venv/bin/abscissa as a stdio command in your MCP client, and pass LINEAR_API_KEY through that client's environment or secret manager.

The key remains outside the repository. The .gitignore excludes common local environment files, including .env and .venv.

What the client can call

Area	Tools
Identity	get_current_user
Issues	create_issue, update_issue, search_issues, get_user_issues, get_issue, assign_issue, add_comment, set_issue_estimate
Issue lifecycle	archive_issue, delete_issue
Dependencies	list_issue_dependencies, add_issue_dependency, remove_issue_dependency
Labels and workflow	list_workflow_states, list_issue_labels, create_label, add_issue_label, remove_issue_label
Teams and people	list_teams, get_team, list_users
Projects	create_project, get_project, list_projects, list_project_issues, set_issue_project, remove_issue_from_project, update_project, archive_project
Cycles	create_cycle, update_cycle, archive_cycle, list_cycles, list_cycle_issues

Search and list tools accept limit and cursor. Their responses keep the same shape:

{
  "items": [],
  "next_cursor": null
}

Pass a non-null next_cursor back as cursor to request the next page.

list_issue_dependencies returns separate blocks and blocked_by lists. Each item includes its relation_id; use it to remove that dependency. Its next_cursors object has separate cursors for each direction.

Destructive actions

archive_issue, archive_project, and delete_issue are marked with MCP's destructiveHint. They refuse to call Linear until the client invokes them with confirm=true.

Deletion requires explicit confirmation: set confirm=true

This prevents an accidental tool call from deleting or archiving data. It does not replace Linear's own access controls: the API key still determines which resources the server may read or change.

Verify the checkout

.venv/bin/ruff check .
.venv/bin/python -m pytest

The current checkout produces:

All checks passed!
..........                                                               [100%]
10 passed

The tests cover pagination bounds and response shape, authenticated-user issue resolution, project membership, cycle queries, dependency direction, confirmation guards, cycle lifecycle operations, and MCP tool registration. GitHub Actions runs the same lint and test commands on Python 3.10, 3.11, 3.12, and 3.13.

Limitations

Abscissa is a local stdio server, not an HTTP service. It needs a running MCP-capable client and a valid Linear API key. The automated suite avoids mutating a real Linear workspace; create, update, archive, and delete behavior is therefore protected by unit tests rather than a live write test.

License

MIT