CallToolResult currently decodes structuredContent through an any field,
which converts JSON numbers to float64 and silently rounds integers
outside the IEEE-754 safe range.
This change decodes structuredContent separately with UseNumber,
preserving wire numbers as json.Number while retaining the existing
decoded object, array, and primitive shapes. The field documentation now
describes that representation. Users who depend on the previous float64
behavior can temporarily restore it with
MCPGODEBUG=structuredcontentfloat64=1.
An end-to-end in-memory client/server regression covers 9007199254740993
from a low-level Server.AddTool result. Additional coverage verifies the
compatibility option restores the legacy rounded float64 value.
Verification:
- gofmt -l .
- go test ./...
- go vet ./...
Fixes#1236
---------
Co-authored-by: Guglielmo Colombo <guglielmoc@google.com>
A fix was submitted to our dependency, tests added to validate the
problematic scenario.
We also added some fuzz tests to check for additional issues, none were
found.
As reported in
https://github.com/modelcontextprotocol/go-sdk/issues/805, case
insensitive unmarshaling can pose security issues. This change adjusts
all non-test and non-example unmarshaling to use a case sensitive mode.
This introduces a new external dependency
`github.com/segmentio/encoding`.
