sem MCP Server by Ataraxy Labs: Setup for Claude, Cursor and Other Apps

• Finds where a function or class is defined

  Looks up an entity by name, or by a free-text description if you do not know the name. Modes also list its callers, its references, or a compact context with its source and callers and callees.

  Try: “Where is submitOrder defined, and who calls it?”

  Read · sem_find

• Searches code for exact text

  Finds an exact string such as an error message or config key, and reports the function or class it sits in rather than just the line.

  Try: “Where does the text "retry limit" appear?”

  Read · sem_grep

• Shows what a change would touch

  Lists what depends on an entity, what it depends on, and which tests are affected, following dependents a few steps out.

  Try: “What breaks if I change submitOrder?”

  Read · sem_impact

• Runs the project's checks and gives a verdict

  Runs the project's compiler, type checker, linter and tests, and any commands from its .sem/check.json, then returns pass, fail or could not decide. It only rechecks what a change can affect when that is provably the same result.

  Try: “Check that my change is correct.”

  Runs code · sem_check

• Summarizes what a human should review

  Builds a review summary for a commit range: touched entities, signature changes, callers left behind and affected tests.

  Try: “What should I review in main..HEAD?”

  Read · sem_certify

• Shows which entities changed between two versions

  Compares two refs, or the working tree, and lists the functions and classes that changed, optionally with before and after source.

  Try: “Which functions changed since main?”

  Read · sem_diff

• Shows how code connects

  Returns a graph of entities and their calls, JS/TS modules, data flow, or the system as a whole.

  Try: “Show the module graph of this package.”

  Read · sem_graph

• Shows how an entity changed over time

  Traces the history of one function or class, or gives repo-wide hotspots and files that change together. It can also give blame for a file.

  Try: “How has submitOrder changed over time?”

  Read · sem_history

Watch out for

• The check tool runs your project's own commands

  It runs compilers, linters, tests and any commands listed in .sem/check.json, which can do anything those commands can. Use it only in repositories you trust. github.com

• Local usage counts, optional upload

  sem counts command names on your machine only, and uploads counts only if you turn telemetry on. DO_NOT_TRACK=1 turns it off. github.com

• Name clash with GNU Parallel

  On systems with GNU Parallel, the command sem may start a different program. Use the npx command or the full path. github.com

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