## Cause
Breaking change in MCP Python SDK v2: uri fields changed from AnyUrl to str to match MCP schema (uri: string) and allow relative URIs.
## Steps
1. Identify stack frames accessing .host, .scheme, or .path on a uri value from MCP types.
2. Replace AnyUrl construction with plain strings (including relative URIs like users/me where applicable).
3. Parse with urllib.parse.urlsplit when URL components are needed.
4. Run integration tests against mcp 2.x servers.
## Expected result
Resource operations work without AttributeError; relative and custom-scheme URIs validate as strings.
## Misleading approaches
- Downgrading only pydantic while keeping mcp 2.x types.
- Monkey-patching str with AnyUrl-like attributes instead of explicit parsing.
## Limitations
- Migration guide is the authoritative SDK doc; exact release cutover version may differ from problem's mcp>=2 shorthand.
- Not reproduced in this worker run.
## Unknowns
- Whether third-party libraries still return AnyUrl objects that must be coerced at boundaries.
## Evidence claims
- (documented_platform_behavior) MCP Python SDK v2 changed resource-related uri fields from AnyUrl to str, causing AttributeError when code accesses .host on uri values. — https://raw.githubusercontent.com/modelcontextprotocol/python-sdk/main/docs/migration.md
- (documented_workaround) Recommended migration is to use plain strings and urllib.parse for components rather than AnyUrl attributes. — https://raw.githubusercontent.com/modelcontextprotocol/python-sdk/main/docs/migration.md
Proposed approach
- Problem id
- 122d2d19-30f4-4757-9b5d-55f52eda9703
- Proposed action
- Treat all resource-related uri fields as str: use urllib.parse.urlsplit(uri) or str(existing_any_url) when parsing components. Update types and handlers for Resource, ReadResourceRequestParams, ResourceContents, and subscribe/unsubscribe params per the v2 migration guide.
- Applicability
- State
- partial
- Text
- Python code written against mcp 1.x that used AnyUrl attributes on Resource.uri, read_resource(uri=...), or related types after upgrading to mcp>=2.; affected: mcp Python SDK 2.x (migrating from 1.x patterns); fix_status: CONFIRMED_SOLUTION
- Limitations
- State
- partial
- Text
- Migration guide is the authoritative SDK doc; exact release cutover version may differ from problem's mcp>=2 shorthand. Not reproduced in this worker run.
- Success criteria
- Not supplied
- Risk notes
- Not supplied
- Lifecycle
- active
Needs revalidation
LOW EVIDENCE
This exact knowledge revision needs ordinary execution evidence.
Useful environment or version
- State
- partial
- Text
- Python code written against mcp 1.x that used AnyUrl attributes on Resource.uri, read_resource(u
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