Add MCP server registry and support server references in tasks by sroussey · Pull Request #307 · workglow-dev/workglow

sroussey · 2026-03-13T22:14:03Z

Summary

This PR introduces a centralized MCP server registry system that allows MCP tasks to reference pre-configured servers by ID instead of requiring inline configuration. It includes a new repository pattern for managing MCP server configurations and updates all MCP-related tasks to support both registry-based and inline server configuration.

Key Changes

New MCP Server Registry System
- Added McpServerRepository base class for managing MCP server configurations with event emission (server_added, server_removed, server_updated)
- Added InMemoryMcpServerRepository for in-memory storage of server configurations
- Added McpServerRegistry with global service registration and input resolver integration
- Added McpServerSchema defining McpServerConfig and McpServerRecord types
Task Configuration Updates
- Updated McpToolCallTask, McpPromptGetTask, McpResourceReadTask, and McpListTask to support a server property with format "mcp-server"
- Made transport no longer required in task configs (can be provided via registry reference)
- Added getMcpServerConfig() helper method to merge registry-based and inline configurations, with inline values taking precedence
- Updated schema validation to allow either registry reference or inline transport configuration
Task Runner Enhancement
- Added schema-aware input resolution in TaskRunner to resolve format-annotated config properties (like mcp-server references) before task execution
- Added output schema resolution to handle format-annotated output properties
Input Resolver Integration
- Registered resolveMcpServerFromRegistry() as the handler for "mcp-server" format, enabling automatic resolution of server IDs to full configurations

Implementation Details

Server configurations can be provided either via the registry (using a server ID string) or inline in task config
Inline configuration values override registry values when both are present
The registry uses a tabular storage interface for flexibility in backend implementation
All MCP tasks now validate that a transport configuration is available from either source before execution
The system integrates with the existing input resolver framework for seamless schema-based resolution

https://claude.ai/code/session_01X1uCtkgCkeH2GJq1QAzUp1

Copilot

Pull request overview

This PR adds an MCP server registry to let MCP-related tasks reference pre-configured servers by ID, and updates task execution to resolve format-annotated config/inputs/outputs via the schema input resolver system.

Changes:

Introduces MCP server registry primitives (schema, repository, in-memory implementation, global registry + input resolver).
Updates MCP tasks to accept a server reference and merge registry-based config with inline overrides.
Enhances TaskRunner to resolve schema-annotated config properties and output properties before/after execution.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 13 comments.

Show a summary per file

File	Description
packages/tasks/src/task/mcp/McpToolCallTask.ts	Adds `server` reference support and merges resolved server config for tool calls + schema discovery.
packages/tasks/src/task/mcp/McpPromptGetTask.ts	Adds `server` reference support and merges resolved server config for prompt retrieval + schema discovery.
packages/tasks/src/task/mcp/McpResourceReadTask.ts	Adds `server` reference support and merges resolved server config for resource reads.
packages/tasks/src/task/mcp/McpListTask.ts	Adds `server` reference support and merges resolved server config for listing tools/resources/prompts.
packages/tasks/src/mcp-server/McpServerSchema.ts	Defines MCP server config/record JSON schemas and related TS types.
packages/tasks/src/mcp-server/McpServerRepository.ts	Implements a tabular-storage-backed repository with event emission for server records.
packages/tasks/src/mcp-server/InMemoryMcpServerRepository.ts	Provides an in-memory repository implementation.
packages/tasks/src/mcp-server/McpServerRegistry.ts	Registers a global MCP server repository service + input resolver for `mcp-server` references.
packages/tasks/src/common.ts	Re-exports the new MCP server registry APIs from the tasks package.
packages/task-graph/src/task/TaskRunner.ts	Resolves schema-annotated config and output properties via `resolveSchemaInputs()` during task runs.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

sroussey · 2026-03-13T22:40:49Z

packages/tasks/src/task/mcp/McpListTask.ts

+  private getMcpServerConfig(input: McpListTaskInput): McpServerConfig {
+    const server = (input as Record<string, unknown>).server as
+      | Record<string, unknown>
+      | string
+      | undefined;
+    const base = typeof server === "object" && server !== null ? server : {};
+    const merged = { ...base } as Record<string, unknown>;
+    for (const key of ["transport", "server_url", "command", "args", "env"] as const) {
+      const val = (input as Record<string, unknown>)[key];
+      if (val !== undefined) {
+        merged[key] = val;
+      }
+    }
+    if (!merged.transport) {
+      throw new Error("MCP server transport is required (provide inline or via server registry)");
+    }
+    return merged as unknown as McpServerConfig;
+  }


@copilot apply changes based on this feedback

packages/task-graph/src/task/TaskRunner.ts

+      // Resolve schema-annotated config properties (e.g., mcp-server references)
+      const configSchemaResult = (this.task.constructor as typeof Task).configSchema();
+      if (configSchemaResult) {
+        const resolvedConfig = await resolveSchemaInputs(
+          this.task.config as Record<string, unknown>,
+          configSchemaResult,
+          { registry: this.registry }
+        );
+        Object.assign(this.task.config, resolvedConfig);
+      }


packages/task-graph/src/task/TaskRunner.ts

+    // Resolve schema-annotated config properties (e.g., mcp-server references)
+    const configSchemaResult = (this.task.constructor as typeof Task).configSchema();
+    if (configSchemaResult) {
+      const resolvedConfig = await resolveSchemaInputs(
+        this.task.config as Record<string, unknown>,
+        configSchemaResult,
+        { registry: this.registry }
+      );
+      Object.assign(this.task.config, resolvedConfig);
+    }


sroussey · 2026-03-13T22:42:23Z

packages/tasks/src/mcp-server/McpServerSchema.ts

+ * A lightweight MCP server configuration suitable for task config/input schemas.
+ *
+ * When a string `server_id` is provided, the input resolver system resolves it
+ * to the full server record from the registry.
+ */


@copilot apply changes based on this feedback

sroussey · 2026-03-13T22:42:38Z

packages/tasks/src/task/mcp/McpToolCallTask.ts

+  required: ["tool_name"],
  if: { properties: { transport: { const: "stdio" } }, required: ["transport"] },
  then: { required: ["command"] },
-  else: { required: ["server_url"] },
+  else: {},


@copilot apply changes based on this feedback

packages/tasks/src/mcp-server/McpServerRepository.ts

+export type McpServerEventListeners = {
+  server_added: (server: McpServerRecord) => void;
+  server_removed: (server: McpServerRecord) => void;
+  server_updated: (server: McpServerRecord) => void;
+};


packages/tasks/src/mcp-server/McpServerRegistry.ts

+// Register the MCP server resolver for format: "mcp-server"
+registerInputResolver("mcp-server", resolveMcpServerFromRegistry);


packages/tasks/src/task/mcp/McpToolCallTask.ts

+  private getMcpServerConfig(): McpServerConfig | undefined {
+    const server = this.config.server as Record<string, unknown> | string | undefined;
+    const base = typeof server === "object" && server !== null ? server : {};
+    const merged = { ...base } as Record<string, unknown>;
+    // Inline fields override registry values
+    for (const key of ["transport", "server_url", "command", "args", "env"] as const) {
+      if (this.config[key] !== undefined) {
+        merged[key] = this.config[key];
+      }
+    }
+    if (!merged.transport) return undefined;
+    return merged as unknown as McpServerConfig;
+  }


packages/tasks/src/task/mcp/McpPromptGetTask.ts

+  required: ["prompt_name"],
  if: { properties: { transport: { const: "stdio" } }, required: ["transport"] },
  then: { required: ["command"] },
-  else: { required: ["server_url"] },
+  else: {},


packages/tasks/src/task/mcp/McpResourceReadTask.ts

+  required: ["resource_uri"],
  if: { properties: { transport: { const: "stdio" } }, required: ["transport"] },
  then: { required: ["command"] },
-  else: { required: ["server_url"] },
+  else: {},
  allOf: mcpServerConfigSchema.allOf,


Copilot · 2026-03-13T22:40:56Z

@sroussey I've opened a new pull request, #309, to work on those changes. Once the pull request is ready, I'll request review from you.

Copilot · 2026-03-13T22:42:29Z

@sroussey I've opened a new pull request, #310, to work on those changes. Once the pull request is ready, I'll request review from you.

Copilot · 2026-03-13T22:42:44Z

@sroussey I've opened a new pull request, #311, to work on those changes. Once the pull request is ready, I'll request review from you.

Copilot · 2026-03-13T22:44:52Z

@sroussey I've opened a new pull request, #312, to work on those changes. Once the pull request is ready, I'll request review from you.

…hemas - Create McpServerSchema, McpServerRepository, InMemoryMcpServerRepository, and McpServerRegistry following the ModelRegistry pattern - MCP servers can now be registered once and referenced by string ID (format: "mcp-server") in task configs and inputs - Extend TaskRunner to run resolveSchemaInputs on config and output schemas, not just input schemas, making the resolver system uniform - Add optional 'server' field to all MCP task configs (ToolCall, ResourceRead, PromptGet) and McpListTask input, with backward-compatible inline config - Inline config fields override registry values for per-task customization https://claude.ai/code/session_01X1uCtkgCkeH2GJq1QAzUp1

…us re-export The workglow meta-package re-exports both @workglow/util and @workglow/tasks, which both exported a type named McpServerConfig. Renamed the tasks version to McpServerTaskConfig to avoid the TS2308 ambiguity error. https://claude.ai/code/session_01X1uCtkgCkeH2GJq1QAzUp1

…ommands

Copilot

Pull request overview

This PR introduces an MCP server registry/repository so MCP-related tasks can reference preconfigured servers by ID (via format: "mcp-server") instead of requiring full inline server configuration, and updates task execution to resolve schema-annotated config/outputs before running.

Changes:

Added MCP server schema + repository + global registry integration (including an input resolver for "mcp-server").
Updated MCP tasks (tool call, prompt get, resource read, list) to accept a server reference and merge it with inline overrides.
Enhanced TaskRunner to resolve schema-annotated config properties and output properties via resolveSchemaInputs().

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 14 comments.

Show a summary per file

File	Description
packages/tasks/src/task/mcp/McpToolCallTask.ts	Adds `server` reference support and merges registry + inline MCP config for tool calls.
packages/tasks/src/task/mcp/McpPromptGetTask.ts	Adds `server` reference support and merges registry + inline MCP config for prompt retrieval.
packages/tasks/src/task/mcp/McpResourceReadTask.ts	Adds `server` reference support and merges registry + inline MCP config for resource reads.
packages/tasks/src/task/mcp/McpListTask.ts	Adds `server` reference support and merges registry + inline MCP config for listing tools/resources/prompts.
packages/tasks/src/mcp-server/McpServerSchema.ts	Introduces schemas/types for MCP server configs and persisted records.
packages/tasks/src/mcp-server/McpServerRepository.ts	Adds a repository abstraction with event emission for MCP server records.
packages/tasks/src/mcp-server/InMemoryMcpServerRepository.ts	Provides an in-memory repository implementation.
packages/tasks/src/mcp-server/McpServerRegistry.ts	Registers a global MCP server repository + input resolver for `"mcp-server"`.
packages/tasks/src/common.ts	Exports MCP server registry/repository/schema APIs from `@workglow/tasks`.
packages/task-graph/src/task/TaskRunner.ts	Resolves schema-annotated config and output properties before/after task execution.
examples/cli/src/storage.ts	Switches CLI MCP persistence to use `McpServerRepository` and shared schemas.
examples/cli/src/lib.ts	Renames exported CLI factory to `createMcpServerRepository`.
examples/cli/src/commands/mcp.ts	Updates CLI MCP commands to use the new repository + `server_id` schema.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

packages/tasks/src/task/mcp/McpPromptGetTask.ts

+    const merged = { ...base } as Record<string, unknown>;
+    for (const key of ["transport", "server_url", "command", "args", "env"] as const) {
+      if (this.config[key] !== undefined) {
+        merged[key] = this.config[key];
+      }
+    }
+    if (!merged.transport) return undefined;
+    return merged as unknown as McpServerConfig;


packages/tasks/src/task/mcp/McpPromptGetTask.ts

+        transport: cfg.transport,
+        server_url: cfg.server_url,
+        command: cfg.command,
+        args: cfg.args,
+        env: cfg.env,


packages/tasks/src/task/mcp/McpResourceReadTask.ts

+  required: ["resource_uri"],
  if: { properties: { transport: { const: "stdio" } }, required: ["transport"] },
  then: { required: ["command"] },
-  else: { required: ["server_url"] },
+  else: {},
  allOf: mcpServerConfigSchema.allOf,


packages/tasks/src/task/mcp/McpResourceReadTask.ts

+    for (const key of ["transport", "server_url", "command", "args", "env"] as const) {
+      if (this.config[key] !== undefined) {
+        merged[key] = this.config[key];
+      }
+    }
+    if (!merged.transport) {
+      throw new Error("MCP server transport is required (provide inline or via server registry)");
+    }


packages/tasks/src/mcp-server/McpServerSchema.ts

+ * When a string `server_id` is provided, the input resolver system resolves it
+ * to the full server record from the registry.


packages/tasks/src/task/mcp/McpToolCallTask.ts

+    // Inline fields override registry values
+    for (const key of ["transport", "server_url", "command", "args", "env"] as const) {
+      if (this.config[key] !== undefined) {
+        merged[key] = this.config[key];
+      }
+    }
+    if (!merged.transport) return undefined;


packages/tasks/src/task/mcp/McpPromptGetTask.ts

  then: { required: ["command"] },
-  else: { required: ["server_url"] },
+  else: {},
  allOf: mcpServerConfigSchema.allOf,


packages/tasks/src/task/mcp/McpToolCallTask.ts

+        transport: cfg.transport,
+        server_url: cfg.server_url,
+        command: cfg.command,
+        args: cfg.args,
+        env: cfg.env,


packages/tasks/src/task/mcp/McpListTask.ts

  },
-  required: ["transport", "list_type"],
+  required: ["list_type"],
  allOf: mcpServerConfigSchema.allOf,


packages/task-graph/src/task/TaskRunner.ts

+        const resolvedConfig = await resolveSchemaInputs(
+          this.task.config as Record<string, unknown>,


sroussey · 2026-03-19T07:35:21Z

@copilot open a new pull request to apply changes based on the comments in this thread

Copilot · 2026-03-19T07:35:29Z

@sroussey I've opened a new pull request, #321, to work on those changes. Once the pull request is ready, I'll request review from you.

sroussey self-assigned this Mar 13, 2026

sroussey requested a review from Copilot March 13, 2026 22:14

Copilot started reviewing on behalf of sroussey March 13, 2026 22:14 View session

Copilot AI reviewed Mar 13, 2026

View reviewed changes

Copilot AI mentioned this pull request Mar 13, 2026

Fix getMcpServerConfig to merge all MCP config keys and validate by transport type #309

Merged

This was referenced Mar 13, 2026

fix: correct JSDoc on McpServerConfigSchema to describe actual resolver mechanics #310

Merged

Fix MCP task config schemas to require server or transport config #311

Merged

Copilot AI mentioned this pull request Mar 13, 2026

Fix McpListTask input schema to require server or transport configuration #312

Merged

claude added 2 commits March 19, 2026 06:45

sroussey force-pushed the claude/add-mcp-task-registry-y9KGE branch from 8e182c2 to 0699590 Compare March 19, 2026 06:47

sroussey changed the base branch from main to rebuild-cli March 19, 2026 06:54

refactor(cli): use McpServerRepository from @workglow/tasks for MCP c…

12d239a

…ommands

sroussey requested a review from Copilot March 19, 2026 07:22

Copilot AI reviewed Mar 19, 2026

View reviewed changes

Copilot AI mentioned this pull request Mar 19, 2026

Fix MCP server registry: auth merging, schema enforcement, config immutability #321

Draft

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Add MCP server registry and support server references in tasks#307

Add MCP server registry and support server references in tasks#307
sroussey wants to merge 3 commits intorebuild-clifrom
claude/add-mcp-task-registry-y9KGE

sroussey commented Mar 13, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

sroussey Mar 13, 2026

Uh oh!

sroussey Mar 13, 2026

Uh oh!

sroussey Mar 13, 2026

Uh oh!

Copilot AI commented Mar 13, 2026

Uh oh!

Copilot AI commented Mar 13, 2026

Uh oh!

Copilot AI commented Mar 13, 2026

Uh oh!

Copilot AI commented Mar 13, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

sroussey commented Mar 19, 2026

Uh oh!

Copilot AI commented Mar 19, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

		// Register the MCP server resolver for format: "mcp-server"
		registerInputResolver("mcp-server", resolveMcpServerFromRegistry);

		* When a string `server_id` is provided, the input resolver system resolves it
		* to the full server record from the registry.

		const resolvedConfig = await resolveSchemaInputs(
		this.task.config as Record<string, unknown>,

Conversation

sroussey commented Mar 13, 2026

Summary

Key Changes

Implementation Details

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

sroussey Mar 13, 2026

Choose a reason for hiding this comment

Uh oh!

sroussey Mar 13, 2026

Choose a reason for hiding this comment

Uh oh!

sroussey Mar 13, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI commented Mar 13, 2026

Uh oh!

Copilot AI commented Mar 13, 2026

Uh oh!

Copilot AI commented Mar 13, 2026

Uh oh!

Copilot AI commented Mar 13, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

sroussey commented Mar 19, 2026

Uh oh!

Copilot AI commented Mar 19, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants