Azure DevOps MCP Server

Instructions

Implementation Reference

• src/features/pull-requests/get-pull-request-changes/feature.ts:27-113 (handler)

  The main handler function that fetches the latest pull request iteration changes, policy evaluations, source/target refs, and generates unified diff patches for changed files using Azure DevOps APIs.

  export async function getPullRequestChanges(
    connection: WebApi,
    options: PullRequestChangesOptions,
  ): Promise<PullRequestChangesResponse> {
    try {
      const gitApi = await connection.getGitApi();
      const [pullRequest, iterations] = await Promise.all([
        gitApi.getPullRequest(
          options.repositoryId,
          options.pullRequestId,
          options.projectId,
        ),
        gitApi.getPullRequestIterations(
          options.repositoryId,
          options.pullRequestId,
          options.projectId,
        ),
      ]);
      if (!iterations || iterations.length === 0) {
        throw new AzureDevOpsError('No iterations found for pull request');
      }
      const latest = iterations[iterations.length - 1];
      const changes = await gitApi.getPullRequestIterationChanges(
        options.repositoryId,
        options.pullRequestId,
        latest.id!,
        options.projectId,
      );
  
      const policyApi = await connection.getPolicyApi();
      const artifactId = `vstfs:///CodeReview/CodeReviewId/${options.projectId}/${options.pullRequestId}`;
      const evaluations = await policyApi.getPolicyEvaluations(
        options.projectId,
        artifactId,
      );
  
      const changeEntries = changes.changeEntries ?? [];
  
      const getBlobText = async (objId?: string): Promise<string> => {
        if (!objId) return '';
        const stream = await gitApi.getBlobContent(
          options.repositoryId,
          objId,
          options.projectId,
        );
  
        const chunks: Uint8Array[] = [];
        return await new Promise<string>((resolve, reject) => {
          stream.on('data', (chunk) => chunks.push(Buffer.from(chunk)));
          stream.on('end', () => resolve(Buffer.concat(chunks).toString('utf8')));
          stream.on('error', reject);
        });
      };
  
      const files = await Promise.all(
        changeEntries.map(async (entry: GitChange) => {
          const path = entry.item?.path || entry.originalPath || '';
          const [oldContent, newContent] = await Promise.all([
            getBlobText(entry.item?.originalObjectId),
            getBlobText(entry.item?.objectId),
          ]);
          const patch = createTwoFilesPatch(
            entry.originalPath || path,
            path,
            oldContent,
            newContent,
          );
          return { path, patch };
        }),
      );
  
      return {
        changes,
        evaluations,
        files,
        sourceRefName: pullRequest?.sourceRefName,
        targetRefName: pullRequest?.targetRefName,
      };
    } catch (error) {
      if (error instanceof AzureDevOpsError) {
        throw error;
      }
      throw new Error(
        `Failed to get pull request changes: ${error instanceof Error ? error.message : String(error)}`,
      );
    }
  }

• src/features/pull-requests/schemas.ts:242-253 (schema)

  Input schema validation using Zod for the get_pull_request_changes tool parameters.

  export const GetPullRequestChangesSchema = z.object({
    projectId: z
      .string()
      .optional()
      .describe(`The ID or name of the project (Default: ${defaultProject})`),
    organizationId: z
      .string()
      .optional()
      .describe(`The ID or name of the organization (Default: ${defaultOrg})`),
    repositoryId: z.string().describe('The ID or name of the repository'),
    pullRequestId: z.number().describe('The ID of the pull request'),
  });

• src/features/pull-requests/schemas.ts:276-282 (schema)

  Response schema defining the structure of data returned by the get_pull_request_changes tool.

  export const GetPullRequestChangesResponseSchema = z.object({
    changes: z.any(),
    evaluations: z.array(z.any()),
    files: z.array(PullRequestFileChangeSchema),
    sourceRefName: z.string().optional(),
    targetRefName: z.string().optional(),
  });

• src/features/pull-requests/tool-definitions.ts:45-50 (registration)

  Tool registration definition including name, description, and JSON schema for inputs.

  {
    name: 'get_pull_request_changes',
    description:
      'Get the files changed in a pull request, their unified diffs, source/target branch names, and the status of policy evaluations',
    inputSchema: zodToJsonSchema(GetPullRequestChangesSchema),
  },

• src/features/pull-requests/index.ts:158-170 (handler)

  Request dispatcher case that parses inputs with schema and invokes the core getPullRequestChanges handler.

  case 'get_pull_request_changes': {
    const params = GetPullRequestChangesSchema.parse(
      request.params.arguments,
    );
    const result = await getPullRequestChanges(connection, {
      projectId: params.projectId ?? defaultProject,
      repositoryId: params.repositoryId,
      pullRequestId: params.pullRequestId,
    });
    return {
      content: [{ type: 'text', text: JSON.stringify(result, null, 2) }],
    };
  }