Build coverage report

Review overall and changed code coverage for a build.

The build coverage page at /builds/{id}/coverage shows the code coverage report generated or imported for one build record.

An Xcode build has no coverage page until you generate the report. Open the build details page and choose Generate coverage report first — until then this page tells you the report was not found. An imported report gets its own build record and opens here as soon as the import succeeds.

View changes with coverage opens the Changes page on the worktree this build measured, with this report already selected — the numbers below become a green-and-red strip against the actual diff.

Headline numbers

Metric	What it measures
Overall coverage	Coverage across the whole project
Changed coverage	Coverage restricted to the lines this branch changed
Covered lines	Executable lines the tests exercised
Executable lines	Lines that could be covered
Uncovered lines	Executable lines the tests never reached

Changed coverage is the number worth reviewing on a pull request. Overall coverage moves slowly and mostly reflects the age of the codebase; changed coverage tells you whether the work in front of you is tested.

Coverage of changed files

Files this branch touched, with their coverage and a Change marker describing how the file was modified. Search by changed file or path.

This table is empty when the branch has no changed source files — which is the expected state for a build made straight off the base branch.

All coverage files

Every file in the report, grouped by target. Search across targets, files, and paths, sort by any column, and Expand all or Collapse all to move through targets quickly.

Column	Notes
Target	The build target the file belongs to
File	File name
Coverage	Percentage of executable lines covered

Importing coverage from other test runners

You can import line coverage without running an Xcode build. The control agent accepts LCOV files such as coverage/lcov.info and Istanbul JSON such as coverage/coverage-final.json.

In a workflow, run the test suite with a Terminal run step, then add Import coverage report from the Builds group. Configure these fields:

Field	What to enter
Worktree	The checkout where the test command wrote the report
Coverage file	A path inside that worktree; coverage/lcov.info is the default
Coverage format	AUTO to detect the file, or explicitly LCOV or ISTANBUL

The import waits for the agent and creates a HOST build record because no simulator or device build ran. It writes build.id and build.coverageSummary to workflow session data. Add Read code coverage afterward when later steps need the per-file and changed-file lists.

The built-in import_coverage_report MCP tool provides the same operation with worktreeId, reportPath, format, and a caller-supplied requestId. You can run it from the Tools page or an MCP client.

The coverage file must stay inside the worktree, must describe at least one file, and cannot exceed 64 MiB. Import requires an online agent that supports coverage imports.

Changed-line coverage is measured against the worktree’s base branch. If the branch or its remote reference cannot be resolved, the import still keeps whole-file coverage, but the changed-file breakdown and line overlay are unavailable.

Related pages

Build details

Where an Xcode coverage report is generated, alongside logs, artifacts, and test results.

Changes

The same report, overlaid line by line on the branch’s diff.

Worktree details

Worktree coverage reports, which measure the lines changed in a branch and its working tree.