add git_show tool

Author: icholy

src/git/README.md

@@ -73,6 +73,12 @@ Please note that mcp-server-git is currently in early development. The functiona
      - `repo_path` (string): Path to Git repository
      - `branch_name` (string): Name of branch to checkout
    - Returns: Confirmation of branch switch
+9. `git_show`
+   - Shows the contents of a commit
+   - Inputs:
+     - `repo_path` (string): Path to Git repository
+     - `revision` (string): The revision (commit hash, branch name, tag) to show
+   - Returns: Contents of the specified commit
 
 ## Installation
 

src/git/src/mcp_server_git/server.py

@@ -52,6 +52,10 @@ class GitCheckout(BaseModel):
     repo_path: str
     branch_name: str
 
+class GitShow(BaseModel):
+    repo_path: str
+    revision: str
+
 class GitTools(str, Enum):
     STATUS = "git_status"
     DIFF_UNSTAGED = "git_diff_unstaged"
@@ -63,6 +67,7 @@ class GitTools(str, Enum):
     LOG = "git_log"
     CREATE_BRANCH = "git_create_branch"
     CHECKOUT = "git_checkout"
+    SHOW = "git_show"
 
 def git_status(repo: git.Repo) -> str:
     return repo.git.status()
@@ -113,6 +118,24 @@ def git_checkout(repo: git.Repo, branch_name: str) -> str:
     repo.git.checkout(branch_name)
     return f"Switched to branch '{branch_name}'"
 
+def git_show(repo: git.Repo, revision: str) -> str:
+    commit = repo.commit(revision)
+    output = [
+        f"Commit: {commit.hexsha}\n"
+        f"Author: {commit.author}\n"
+        f"Date: {commit.authored_datetime}\n"
+        f"Message: {commit.message}\n"
+    ]
+    if commit.parents:
+        parent = commit.parents[0]
+        diff = parent.diff(commit, create_patch=True)
+    else:
+        diff = commit.diff(git.NULL_TREE, create_patch=True)
+    for d in diff:
+        output.append(f"\n--- {d.a_path}\n+++ {d.b_path}\n")
+        output.append(d.diff.decode('utf-8'))
+    return "".join(output)
+
 async def serve(repository: Path | None) -> None:
     logger = logging.getLogger(__name__)
 
@@ -179,6 +202,11 @@ async def list_tools() -> list[Tool]:
                 description="Switches branches",
                 inputSchema=GitCheckout.schema(),
             ),
+            Tool(
+                name=GitTools.SHOW,
+                description="Shows the contents of a commit",
+                inputSchema=GitShow.schema(),
+            )
         ]
 
     async def list_repos() -> Sequence[str]:
@@ -290,6 +318,13 @@ async def call_tool(name: str, arguments: dict) -> list[TextContent]:
                     text=result
                 )]
 
+            case GitTools.SHOW:
+                result = git_show(repo, arguments["revision"])
+                return [TextContent(
+                    type="text",
+                    text=result
+                )]
+
             case _:
                 raise ValueError(f"Unknown tool: {name}")