feat: add responseType parameter for JSON output in tools

packages/mcp-server/src/internal/formatting.ts

@@ -683,44 +683,72 @@ export function formatIssueOutput({
   event,
   apiService,
   autofixState,
+  responseType = "md",
 }: {
   organizationSlug: string;
   issue: Issue;
   event: Event;
   apiService: SentryApiService;
   autofixState?: AutofixRunState;
+  responseType?: "md" | "json";
 }) {
-  let output = `# Issue ${issue.shortId} in **${organizationSlug}**\n\n`;
-  output += `**Description**: ${issue.title}\n`;
-  output += `**Culprit**: ${issue.culprit}\n`;
-  output += `**First Seen**: ${new Date(issue.firstSeen).toISOString()}\n`;
-  output += `**Last Seen**: ${new Date(issue.lastSeen).toISOString()}\n`;
-  output += `**Occurrences**: ${issue.count}\n`;
-  output += `**Users Impacted**: ${issue.userCount}\n`;
-  output += `**Status**: ${issue.status}\n`;
-  output += `**Platform**: ${issue.platform}\n`;
-  output += `**Project**: ${issue.project.name}\n`;
-  output += `**URL**: ${apiService.getIssueUrl(organizationSlug, issue.shortId)}\n`;
-  output += "\n";
-  output += "## Event Details\n\n";
-  output += `**Event ID**: ${event.id}\n`;
+  let mdOutput = `# Issue ${issue.shortId} in **${organizationSlug}**\n\n`;
+  const issueUrl = apiService.getIssueUrl(organizationSlug, issue.shortId);
+  const firstSeen = new Date(issue.firstSeen).toISOString();
+  const lastSeen = new Date(issue.lastSeen).toISOString();
+  const jsonOutput: Record<string, unknown> = {
+    issue: {
+      ...issue,
+      firstSeen,
+      lastSeen,
+      url: issueUrl,
+    },
+    event: {
+      id: event.id,
+    },
+  };
+  mdOutput += `**Description**: ${issue.title}\n`;
+  mdOutput += `**Culprit**: ${issue.culprit}\n`;
+  mdOutput += `**First Seen**: ${firstSeen}\n`;
+  mdOutput += `**Last Seen**: ${lastSeen}\n`;
+  mdOutput += `**Occurrences**: ${issue.count}\n`;
+  mdOutput += `**Users Impacted**: ${issue.userCount}\n`;
+  mdOutput += `**Status**: ${issue.status}\n`;
+  mdOutput += `**Platform**: ${issue.platform}\n`;
+  mdOutput += `**Project**: ${issue.project.name}\n`;
+  mdOutput += `**URL**: ${issueUrl}\n`;
+  mdOutput += "\n";
+  mdOutput += "## Event Details\n\n";
+  mdOutput += `**Event ID**: ${event.id}\n`;
   if (event.type === "error") {
-    output += `**Occurred At**: ${new Date((event as z.infer<typeof ErrorEventSchema>).dateCreated).toISOString()}\n`;
+    const occurredAt = new Date(
+      (event as z.infer<typeof ErrorEventSchema>).dateCreated,
+    ).toISOString();
+    mdOutput += `**Occurred At**: ${occurredAt}\n`;
+    (jsonOutput.event as Record<string, unknown>).occurredAt = occurredAt;
   }
   if (event.message) {
-    output += `**Message**:\n${event.message}\n`;
+    mdOutput += `**Message**:\n${event.message}\n`;
+    (jsonOutput.event as Record<string, unknown>).message = event.message;
   }
-  output += "\n";
-  output += formatEventOutput(event);
+  mdOutput += "\n";
+  mdOutput += formatEventOutput(event);
 
   // Add Seer context if available
   if (autofixState) {
-    output += formatSeerContext(autofixState);
+    const formattedSeerContext = formatSeerContext(autofixState);
+    mdOutput += formattedSeerContext;
+    jsonOutput.autofixState = formattedSeerContext;
   }
 
-  output += "# Using this information\n\n";
-  output += `- You can reference the IssueID in commit messages (e.g. \`Fixes ${issue.shortId}\`) to automatically close the issue when the commit is merged.\n`;
-  output +=
+  mdOutput += "# Using this information\n\n";
+  mdOutput += `- You can reference the IssueID in commit messages (e.g. \`Fixes ${issue.shortId}\`) to automatically close the issue when the commit is merged.\n`;
+  mdOutput +=
     "- The stacktrace includes both first-party application code as well as third-party code, its important to triage to first-party code.\n";
-  return output;
+
+  if (responseType === "json") {
+    return jsonOutput;
+  }
+
+  return mdOutput;
 }

packages/mcp-server/src/schema.ts

@@ -121,3 +121,8 @@ export const ParamAttachmentId = z
   .string()
   .trim()
   .describe("The ID of the attachment to download.");
+
+export const ResponseType = z
+  .enum(["md", "json"])
+  .default("md")
+  .describe("The format of the tool's response. Defaults to markdown.");

packages/mcp-server/src/server.ts

@@ -408,6 +408,17 @@ export async function configureServer({
                       content: output,
                     };
                   }
+                  // if the tool returns a plain object, convert to JSON text
+                  if (typeof output === "object" && output !== null) {
+                    return {
+                      content: [
+                        {
+                          type: "text" as const,
+                          text: JSON.stringify(output),
+                        },
+                      ],
+                    };
+                  }
                   throw new Error(`Invalid tool output: ${output}`);
                 } catch (error) {
                   span.setStatus({

packages/mcp-server/src/tools/create-team.test.ts

@@ -27,4 +27,26 @@ describe("create_team", () => {
       "
     `);
   });
+  it("returns json", async () => {
+    const result = await createTeam.handler(
+      {
+        organizationSlug: "sentry-mcp-evals",
+        name: "the-goats",
+        responseType: "json",
+      },
+      {
+        accessToken: "access-token",
+        userId: "1",
+        organizationSlug: null,
+      },
+    );
+    expect(result).toMatchObject({
+      organizationSlug: "sentry-mcp-evals",
+      team: {
+        id: "4509109078196224",
+        slug: "the-goats",
+        name: "the-goats",
+      },
+    });
+  });
 });

packages/mcp-server/src/tools/create-team.ts

@@ -3,7 +3,7 @@ import { setTag } from "@sentry/core";
 import { defineTool } from "./utils/defineTool";
 import { apiServiceFromContext } from "./utils/api-utils";
 import type { ServerContext } from "../types";
-import { ParamOrganizationSlug, ParamRegionUrl } from "../schema";
+import { ParamOrganizationSlug, ParamRegionUrl, ResponseType } from "../schema";
 
 export default defineTool({
   name: "create_team",
@@ -32,6 +32,7 @@ export default defineTool({
     organizationSlug: ParamOrganizationSlug,
     regionUrl: ParamRegionUrl.optional(),
     name: z.string().trim().describe("The name of the team to create."),
+    responseType: ResponseType.optional(),
   },
   async handler(params, context: ServerContext) {
     const apiService = apiServiceFromContext(context, {
@@ -45,12 +46,20 @@ export default defineTool({
       organizationSlug,
       name: params.name,
     });
-    let output = `# New Team in **${organizationSlug}**\n\n`;
-    output += `**ID**: ${team.id}\n`;
-    output += `**Slug**: ${team.slug}\n`;
-    output += `**Name**: ${team.name}\n`;
-    output += "# Using this information\n\n";
-    output += `- You should always inform the user of the Team Slug value.\n`;
-    return output;
+    let mdOutput = `# New Team in **${organizationSlug}**\n\n`;
+    mdOutput += `**ID**: ${team.id}\n`;
+    mdOutput += `**Slug**: ${team.slug}\n`;
+    mdOutput += `**Name**: ${team.name}\n`;
+    mdOutput += "# Using this information\n\n";
+    mdOutput += `- You should always inform the user of the Team Slug value.\n`;
+
+    if (params.responseType === "json") {
+      return {
+        organizationSlug,
+        team,
+      };
+    }
+
+    return mdOutput;
   },
 });

packages/mcp-server/src/tools/get-issue-details.test.ts

@@ -294,4 +294,37 @@ describe("get_issue_details", () => {
     expect(result).toContain("## Seer AI Analysis");
     expect(result).toContain("Consolidate bottle and price data fetching");
   });
+
+  it("returns json", async () => {
+    const result = await getIssueDetails.handler(
+      {
+        responseType: "json",
+        organizationSlug: "sentry-mcp-evals",
+        issueId: "CLOUDFLARE-MCP-41",
+        eventId: undefined,
+        issueUrl: undefined,
+        regionUrl: undefined,
+      },
+      {
+        accessToken: "access-token",
+        userId: "1",
+        organizationSlug: null,
+      },
+    );
+    expect(result).toMatchObject({
+      autofixState: expect.any(String),
+      event: {
+        id: "7ca573c0f4814912aaa9bdc77d1a7d51",
+        occurredAt: "2025-04-08T21:15:04.000Z",
+      },
+      issue: {
+        count: "25",
+        culprit: "Object.fetch(index)",
+        firstSeen: "2025-04-03T22:51:19.403Z",
+        id: "6507376925",
+        lastSeen: "2025-04-12T11:34:11.000Z",
+        url: expect.any(String),
+      },
+    });
+  });
 });

packages/mcp-server/src/tools/get-issue-details.ts

@@ -10,6 +10,7 @@ import {
   ParamRegionUrl,
   ParamIssueShortId,
   ParamIssueUrl,
+  ResponseType,
 } from "../schema";
 
 export default defineTool({
@@ -55,6 +56,7 @@ export default defineTool({
     issueId: ParamIssueShortId.optional(),
     eventId: z.string().trim().describe("The ID of the event.").optional(),
     issueUrl: ParamIssueUrl.optional(),
+    responseType: ResponseType.optional(),
   },
   async handler(params, context: ServerContext) {
     const apiService = apiServiceFromContext(context, {
@@ -103,6 +105,7 @@ export default defineTool({
         event,
         apiService,
         autofixState,
+        responseType: params.responseType,
       });
     }
 
@@ -165,6 +168,7 @@ export default defineTool({
       event,
       apiService,
       autofixState,
+      responseType: params.responseType,
     });
   },
 });

packages/mcp-server/src/tools/types.ts

@@ -15,7 +15,11 @@ export interface ToolConfig<
   handler: (
     params: z.infer<z.ZodObject<TSchema>>,
     context: ServerContext,
-  ) => Promise<string | (TextContent | ImageContent | EmbeddedResource)[]>;
+  ) => Promise<
+    | string
+    | Record<string, unknown>
+    | (TextContent | ImageContent | EmbeddedResource)[]
+  >;
 }
 
 /**

packages/mcp-server/src/tools/update-project.test.ts

@@ -73,4 +73,31 @@ describe("update_project", () => {
       "
     `);
   });
+  it("returns json", async () => {
+    const result = await updateProject.handler(
+      {
+        organizationSlug: "sentry-mcp-evals",
+        projectSlug: "cloudflare-mcp",
+        name: undefined,
+        slug: undefined,
+        platform: undefined,
+        teamSlug: "backend-team",
+        regionUrl: undefined,
+        responseType: "json",
+      },
+      {
+        accessToken: "access-token",
+        userId: "1",
+        organizationSlug: null,
+      },
+    );
+    expect(result).toMatchObject({
+      organizationSlug: "sentry-mcp-evals",
+      project: {
+        id: "4509106749636608",
+        slug: "cloudflare-mcp",
+        name: "cloudflare-mcp",
+      },
+    });
+  });
 });

packages/mcp-server/src/tools/update-project.ts

@@ -12,6 +12,7 @@ import {
   ParamProjectSlug,
   ParamPlatform,
   ParamTeamSlug,
+  ResponseType,
 } from "../schema";
 
 export default defineTool({
@@ -69,6 +70,7 @@ export default defineTool({
     teamSlug: ParamTeamSlug.optional().describe(
       "The team to assign this project to. Note: this will replace the current team assignment.",
     ),
+    responseType: ResponseType.optional(),
   },
   async handler(params, context: ServerContext) {
     const apiService = apiServiceFromContext(context, {
@@ -124,12 +126,12 @@ export default defineTool({
       }
     }
 
-    let output = `# Updated Project in **${organizationSlug}**\n\n`;
-    output += `**ID**: ${project.id}\n`;
-    output += `**Slug**: ${project.slug}\n`;
-    output += `**Name**: ${project.name}\n`;
+    let mdOutput = `# Updated Project in **${organizationSlug}**\n\n`;
+    mdOutput += `**ID**: ${project.id}\n`;
+    mdOutput += `**Slug**: ${project.slug}\n`;
+    mdOutput += `**Name**: ${project.name}\n`;
     if (project.platform) {
-      output += `**Platform**: ${project.platform}\n`;
+      mdOutput += `**Platform**: ${project.platform}\n`;
     }
 
     // Display what was updated
@@ -141,16 +143,24 @@ export default defineTool({
       updates.push(`team assignment to "${params.teamSlug}"`);
 
     if (updates.length > 0) {
-      output += `\n## Updates Applied\n`;
-      output += updates.map((update) => `- Updated ${update}`).join("\n");
-      output += `\n`;
+      mdOutput += `\n## Updates Applied\n`;
+      mdOutput += updates.map((update) => `- Updated ${update}`).join("\n");
+      mdOutput += `\n`;
     }
 
-    output += "\n# Using this information\n\n";
-    output += `- The project is now accessible at slug: \`${project.slug}\`\n`;
+    mdOutput += "\n# Using this information\n\n";
+    mdOutput += `- The project is now accessible at slug: \`${project.slug}\`\n`;
     if (params.teamSlug) {
-      output += `- The project is now assigned to the \`${params.teamSlug}\` team\n`;
+      mdOutput += `- The project is now assigned to the \`${params.teamSlug}\` team\n`;
     }
-    return output;
+
+    if (params.responseType === "json") {
+      return {
+        organizationSlug,
+        project,
+      };
+    }
+
+    return mdOutput;
   },
 });

packages/mcp-server/src/tools/whoami.test.ts

@@ -19,4 +19,23 @@ describe("whoami", () => {
     `,
     );
   });
+  it("returns json", async () => {
+    const result = await whoami.handler(
+      { responseType: "json" },
+      {
+        accessToken: "access-token",
+        userId: "1",
+        organizationSlug: null,
+      },
+    );
+    expect(result).toMatchInlineSnapshot(`
+      {
+        "user": {
+          "email": "[email protected]",
+          "id": "1",
+          "name": "John Doe",
+        },
+      }
+    `);
+  });
 });