fix(databricks-mcp): pin mcp dependency to <2.0.0 - #457
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mcp 2.0.0 removes the legacy `streamablehttp_client` symbol from `mcp.client.streamable_http`, which causes `databricks-mcp 0.9.0` to fail at import time on any fresh install that resolves to mcp 2.x. Add an upper bound `mcp>=1.13.0,<2.0.0` so the dependency resolver picks a compatible 1.x release, and bump `databricks-mcp` to 0.9.1. Also fix a pre-existing typecheck failure in `integrations/langchain/tests/unit_tests/test_chat_models.py` by using `InputTokensDetails.model_construct(...)` for the `cache_write_tokens` field, which is not accepted as a constructor argument in some openai versions used in CI. Signed-off-by: Pi Agent <pi-agent@databricks.com>
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PR databricks#457 pinned `mcp>=1.13.0,<2.0.0` as a stopgap because mcp 2.0.0 removed the legacy `streamablehttp_client` symbol (and reworked the transport/session and auth APIs), which broke `databricks-mcp` at import time on fresh installs that resolved to mcp 2.x. This is the proper fix: make the code compatible with mcp 2.x while staying backward compatible with mcp 1.x, then remove the install-time cap so future mcp majors are not blocked at resolve time. ## Summary - Detect the installed mcp major (`_MCP_V2 = try: from mcp import Client`) and route both code paths through a single `_open_mcp_session()` helper: - mcp 2.x: attach `DatabricksOAuthClientProvider` (now an `httpx2.Auth`) to an `httpx2.AsyncClient` handed to `streamable_http_client(url, http_client=...)`, wrapped in `mcp.Client` (which performs the initialize handshake itself). - mcp 1.x: `streamablehttp_client(url, auth=...)` + `ClientSession` + explicit `initialize()`, as before. - `oauth_provider.py`: no code change needed (subclassing `OAuthClientProvider` picks up `httpx2.Auth` automatically on v2); docstring updated to show both usage patterns. - Widen the dependency to `mcp>=1.13.0` (no upper bound). - Bump `databricks-mcp` to 0.9.2. - Update tests for mcp 2.x API renames while keeping them runnable on 1.x: build `Tool` via `model_validate({"inputSchema": ...})` (2.x renamed the field to `input_schema`), import `MCPError` (renamed from `McpError`) with a fallback, and patch the version-agnostic `_open_mcp_session`. The integration-test `raw_mcp_session` helper is now version-aware. ## Test Plan - `uv run pytest tests/unit_tests/` — 113 passed against mcp 1.24.0. - Same suite — 113 passed against mcp 2.0.0. - `ty check` (ty 0.0.23) clean against mcp 2.0.0; `ruff check` / `ruff format` clean. - Verified the real v2 wiring (`httpx2.AsyncClient` + `streamable_http_client` + `Client`) constructs and reaches the transport layer end-to-end. ## Type of change - [x] Bug fix (non-breaking change which fixes an issue) ## Changelog databricks-mcp is now compatible with mcp 2.x (and remains compatible with mcp 1.x). Signed-off-by: Zeyi (Rice) Fan <zeyi.f@databricks.com>
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mcp 2.0.0 removes the legacy
streamablehttp_clientsymbol frommcp.client.streamable_http, which causesdatabricks-mcp 0.9.0to fail at import time on any fresh install that resolves to mcp 2.x.This change adds an upper bound
mcp>=1.13.0,<2.0.0so the dependency resolver picks a compatible 1.x release, and bumpsdatabricks-mcpto0.9.1.uv run pytest tests/unit_tests -qand lint passes withuv run ruff check .