feat(skill): add MCP adapter for external tools #434

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aditya merged 6 commits from feature/m3-mcp-adapter into master 2026-02-27 07:28:15 +00:00

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aditya commented 2026-02-25 14:24:16 +00:00

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Summary

Implement MCP adapter runtime (issue #159) that connects to external MCP servers, enumerates their tools, and registers them in ToolRegistry with source=mcp.

Changes

Core Implementation (src/cleveragents/tool/mcp_adapter.py)

• McpAdapter: manages connection lifecycle (connect, disconnect, reconnect) for stdio, SSE, and streamable-http transports with configurable timeouts
• McpToolInstance: implements the four-stage ToolInstance protocol (discover, activate, execute, deactivate) for MCP-sourced tools
• McpToolDescriptor: intermediate mapping from MCP SDK Tool objects to internal schema, extracting capability flags from MCP ToolAnnotations (readOnlyHint → read_only, destructiveHint → writes, idempotentHint → idempotent)
• map_mcp_tool_to_spec: converts descriptors to ToolSpec with source="mcp" and populated source_metadata
• register_mcp_tools: end-to-end pipeline that discovers, filters (include/exclude), and registers tools
• Error hierarchy: McpAdapterError → McpConnectionError, McpToolNotFoundError, McpInvocationError, McpTimeoutError
• _AsyncBridge: background daemon thread for bridging async MCP SDK to sync ToolInstance protocol

Dependency

• Added mcp>=1.0.0 to pyproject.toml

Tests

• Behave: 23 scenarios in features/mcp_adapter.feature covering connection lifecycle, tool discovery, annotation mapping, invocation, error handling, filtering, ToolSpec mapping, ToolInstance protocol, and registry integration
• Robot: 10 E2E test cases in robot/mcp_adapter.robot with robot/helper_mcp_adapter.py helper
• ASV: 6 benchmark suites in benchmarks/mcp_runtime_bench.py

Documentation

• docs/reference/mcp_adapter.md: architecture, configuration, lifecycle, transports, schema mapping, invocation, error handling, async bridge

Closes #159

## Summary Implement MCP adapter runtime (issue #159) that connects to external MCP servers, enumerates their tools, and registers them in ToolRegistry with `source=mcp`. ## Changes ### Core Implementation (`src/cleveragents/tool/mcp_adapter.py`) - **McpAdapter**: manages connection lifecycle (connect, disconnect, reconnect) for stdio, SSE, and streamable-http transports with configurable timeouts - **McpToolInstance**: implements the four-stage ToolInstance protocol (discover, activate, execute, deactivate) for MCP-sourced tools - **McpToolDescriptor**: intermediate mapping from MCP SDK Tool objects to internal schema, extracting capability flags from MCP ToolAnnotations (readOnlyHint → read_only, destructiveHint → writes, idempotentHint → idempotent) - **map_mcp_tool_to_spec**: converts descriptors to ToolSpec with source="mcp" and populated source_metadata - **register_mcp_tools**: end-to-end pipeline that discovers, filters (include/exclude), and registers tools - **Error hierarchy**: McpAdapterError → McpConnectionError, McpToolNotFoundError, McpInvocationError, McpTimeoutError - **_AsyncBridge**: background daemon thread for bridging async MCP SDK to sync ToolInstance protocol ### Dependency - Added `mcp>=1.0.0` to `pyproject.toml` ### Tests - **Behave**: 23 scenarios in `features/mcp_adapter.feature` covering connection lifecycle, tool discovery, annotation mapping, invocation, error handling, filtering, ToolSpec mapping, ToolInstance protocol, and registry integration - **Robot**: 10 E2E test cases in `robot/mcp_adapter.robot` with `robot/helper_mcp_adapter.py` helper - **ASV**: 6 benchmark suites in `benchmarks/mcp_runtime_bench.py` ### Documentation - `docs/reference/mcp_adapter.md`: architecture, configuration, lifecycle, transports, schema mapping, invocation, error handling, async bridge ## Closes #159

aditya added this to the v3.1.0 milestone 2026-02-25 14:24:16 +00:00

aditya added 3 commits 2026-02-25 14:24:16 +00:00

feat(skill): add MCP adapter for external tools ... ee82d6101e

Implement MCPToolAdapter to connect to external MCP servers, enumerate
tools, and register them in ToolRegistry with source="mcp". Includes
connect/reconnect/disconnect lifecycle with timeout enforcement, input
validation on invoke, capability inference, Behave/Robot/ASV tests, and
docs/reference/mcp_adapter.md.

ISSUES CLOSED: #159

chore(changelog): add MCP adapter entry 2deddd3fe2

refactor(mcp): fix mock placement, type annotation, and constructor validation ... 2f9707cfdf

- Extract MockMCPTransport to features/mocks/mock_mcp_transport.py
- Use ToolRegistry type with TYPE_CHECKING in register_tools()
- Move transport config validation into __init__ via _validate_config()

aditya requested review from CoreRasurae 2026-02-25 14:43:16 +00:00

CoreRasurae approved these changes 2026-02-25 15:07:21 +00:00

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All tests passing, approved!

All tests passing, approved!

freemo changed title from feature/m3-mcp-adapter to feat(skill): add MCP adapter for external tools 2026-02-25 18:12:28 +00:00

freemo added the

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freemo added a new dependency 2026-02-25 18:12:31 +00:00

#159 feat(skill): add MCP adapter for external tools

aditya added 1 commit 2026-02-26 06:50:17 +00:00

Merge branch 'master' into feature/m3-mcp-adapter 519e26fb02

aditya dismissed CoreRasurae's review 2026-02-26 06:50:17 +00:00

Reason:

New commits pushed, approval review dismissed automatically according to repository settings

aditya requested review from CoreRasurae 2026-02-26 06:50:42 +00:00

aditya added 1 commit 2026-02-26 13:32:32 +00:00

Merge branch 'master' into feature/m3-mcp-adapter 595cfd172f

CoreRasurae approved these changes 2026-02-26 16:05:52 +00:00

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Tests passing, changelog updated, documentation updated. Looks good. Approving

Tests passing, changelog updated, documentation updated. Looks good. Approving

brent.edwards force-pushed feature/m3-mcp-adapter from 595cfd172f to 9221dcadc3 2026-02-26 19:56:37 +00:00 Compare

brent.edwards dismissed CoreRasurae's review 2026-02-26 19:56:37 +00:00

Reason:

New commits pushed, approval review dismissed automatically according to repository settings

aditya force-pushed feature/m3-mcp-adapter from 9221dcadc3 to a0f56228e2 2026-02-27 06:46:38 +00:00 Compare

aditya merged commit ab9732c2a1 into master 2026-02-27 07:28:15 +00:00

aditya deleted branch feature/m3-mcp-adapter 2026-02-27 07:28:16 +00:00

aditya referenced this pull request from a commit 2026-02-27 07:28:16 +00:00

Merge pull request 'feat(skill): add MCP adapter for external tools' (#434) from feature/m3-mcp-adapter into master

freemo added the

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#159 feat(skill): add MCP adapter for external tools

cleveragents/cleveragents-core

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