feat: support creating tools using go-struct-style input schema #534
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
WalkthroughAdds support for specifying tool input schemas from Go struct types (generic Changes
Estimated code review effort🎯 2 (Simple) | ⏱️ ~8 minutes Possibly related issues
Possibly related PRs
Suggested labels
Suggested reviewers
📜 Recent review detailsConfiguration used: CodeRabbit UI 📒 Files selected for processing (1)
✅ Files skipped from review due to trivial changes (1)
✨ Finishing Touches🧪 Generate unit tests
Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out. 🪧 TipsChatThere are 3 ways to chat with CodeRabbit:
SupportNeed help? Create a ticket on our support page for assistance with any issues or questions. CodeRabbit Commands (Invoked using PR/Issue comments)Type Other keywords and placeholders
CodeRabbit Configuration File (
|
Grivn
force-pushed
the
main
branch
3 times, most recently
from
35c4a65 to
712822b
Compare
Grivn
changed the title
![coderabbitai[bot]](https://avatars.githubusercontent.com/in/347564?s=60&v=4){kind=small}
There was a problem hiding this comment.
Actionable comments posted: 3
🧹 Nitpick comments (1)
mcp/tools_test.go (1)
546-547: Fix incorrect comment referencing output schema.The comment references "RawOutputSchema" but should reference "RawInputSchema" since this test is for input schema functionality.
Apply this diff to fix the comment:
- // Check that RawOutputSchema was set + // Check that RawInputSchema was set
📜 Review details
Configuration used: CodeRabbit UI
Review profile: CHILL
Plan: Pro
📒 Files selected for processing (4)
examples/structured_input_and_output/README.md(2 hunks)examples/structured_input_and_output/main.go(3 hunks)mcp/tools.go(1 hunks)mcp/tools_test.go(1 hunks)
🚧 Files skipped from review as they are similar to previous changes (3)
- examples/structured_input_and_output/README.md
- examples/structured_input_and_output/main.go
- mcp/tools.go
🧰 Additional context used
🧠 Learnings (7)
📓 Common learnings
Learnt from: xinwo
PR: mark3labs/mcp-go#35
File: mcp/tools.go:0-0
Timestamp: 2025-03-04T07:00:57.111Z
Learning: The Tool struct in the mark3labs/mcp-go project should handle both InputSchema and RawInputSchema consistently between MarshalJSON and UnmarshalJSON methods, even though the tools response from MCP server typically doesn't contain rawInputSchema.
Learnt from: xinwo
PR: mark3labs/mcp-go#35
File: mcp/tools.go:0-0
Timestamp: 2025-03-04T07:00:57.111Z
Learning: The Tool struct in mark3labs/mcp-go handles both InputSchema and RawInputSchema formats. When unmarshaling JSON, it first tries to parse into a structured ToolInputSchema format, and if that fails, it falls back to using the raw schema format, providing symmetry with the MarshalJSON method.
Learnt from: xinwo
PR: mark3labs/mcp-go#35
File: mcp/tools.go:107-137
Timestamp: 2025-03-04T06:59:43.882Z
Learning: Tool responses from the MCP server shouldn't contain RawInputSchema, which is why the UnmarshalJSON method for the Tool struct is implemented to handle only the structured InputSchema format.
Learnt from: davidleitw
PR: mark3labs/mcp-go#451
File: mcp/tools.go:1192-1217
Timestamp: 2025-06-26T09:38:18.629Z
Learning: In mcp-go project, the maintainer prefers keeping builder pattern APIs simple without excessive validation for edge cases. The WithOutput* functions are designed to assume correct usage rather than defensive programming, following the principle of API simplicity over comprehensive validation.
Learnt from: ezynda3
PR: mark3labs/mcp-go#461
File: server/sampling.go:22-26
Timestamp: 2025-06-30T07:13:17.052Z
Learning: In the mark3labs/mcp-go project, the MCPServer.capabilities field is a struct value (serverCapabilities), not a pointer, so it cannot be nil and doesn't require nil checking. Only pointer fields within the capabilities struct should be checked for nil.
📚 Learning: the tool struct in mark3labs/mcp-go handles both inputschema and rawinputschema formats. when unmars...
Learnt from: xinwo
PR: mark3labs/mcp-go#35
File: mcp/tools.go:0-0
Timestamp: 2025-03-04T07:00:57.111Z
Learning: The Tool struct in mark3labs/mcp-go handles both InputSchema and RawInputSchema formats. When unmarshaling JSON, it first tries to parse into a structured ToolInputSchema format, and if that fails, it falls back to using the raw schema format, providing symmetry with the MarshalJSON method.
Applied to files:
mcp/tools_test.go
📚 Learning: the tool struct in the mark3labs/mcp-go project should handle both inputschema and rawinputschema co...
Learnt from: xinwo
PR: mark3labs/mcp-go#35
File: mcp/tools.go:0-0
Timestamp: 2025-03-04T07:00:57.111Z
Learning: The Tool struct in the mark3labs/mcp-go project should handle both InputSchema and RawInputSchema consistently between MarshalJSON and UnmarshalJSON methods, even though the tools response from MCP server typically doesn't contain rawInputSchema.
Applied to files:
mcp/tools_test.go
📚 Learning: tool responses from the mcp server shouldn't contain rawinputschema, which is why the unmarshaljson ...
Learnt from: xinwo
PR: mark3labs/mcp-go#35
File: mcp/tools.go:107-137
Timestamp: 2025-03-04T06:59:43.882Z
Learning: Tool responses from the MCP server shouldn't contain RawInputSchema, which is why the UnmarshalJSON method for the Tool struct is implemented to handle only the structured InputSchema format.
Applied to files:
mcp/tools_test.go
📚 Learning: in go mcp server, servertool.tool field is only used for tool listing and indexing, not for tool exe...
Learnt from: floatingIce91
PR: mark3labs/mcp-go#401
File: server/server.go:1082-1092
Timestamp: 2025-06-23T11:10:42.948Z
Learning: In Go MCP server, ServerTool.Tool field is only used for tool listing and indexing, not for tool execution or middleware. During handleToolCall, only the Handler field is used, so dynamic tools don't need the Tool field populated.
Applied to files:
mcp/tools_test.go
📚 Learning: in the mcptest package, prefer returning errors from helper functions rather than calling t.fatalf()...
Learnt from: octo
PR: mark3labs/mcp-go#149
File: mcptest/mcptest.go:0-0
Timestamp: 2025-04-21T21:26:32.945Z
Learning: In the mcptest package, prefer returning errors from helper functions rather than calling t.Fatalf() directly, giving callers flexibility in how to handle errors.
Applied to files:
mcp/tools_test.go
📚 Learning: in mcp-go project, the maintainer prefers keeping builder pattern apis simple without excessive vali...
Learnt from: davidleitw
PR: mark3labs/mcp-go#451
File: mcp/tools.go:1192-1217
Timestamp: 2025-06-26T09:38:18.629Z
Learning: In mcp-go project, the maintainer prefers keeping builder pattern APIs simple without excessive validation for edge cases. The WithOutput* functions are designed to assume correct usage rather than defensive programming, following the principle of API simplicity over comprehensive validation.
Applied to files:
mcp/tools_test.go
🧬 Code Graph Analysis (1)
mcp/tools_test.go (1)
mcp/tools.go (3)
NewTool(658-680)WithDescription(701-705)WithInputSchema(709-735)
🔇 Additional comments (1)
mcp/tools_test.go (1)
541-544: ConfirmrequiredTag Handling in Schema GenerationThe
invopop/jsonschema-based generator inWithInputSchemadoes recognize the,requiredoption on Gojsontags and pushes those field names into the schema’srequiredarray. Your test’s use ofjson:"name,required"is valid and aligns with both our examples and the schema library’s expectations.No changes needed here—please disregard the original concern.
|
looking forward this feature |
|
@Grivn could you add some bit of documentation in |
Add comprehensive documentation for the new struct-based schema features introduced in commit b46b0d7, including: - Input schema definition using Go structs with WithInputSchema - Output schema definition using WithOutputSchema - Structured tool handlers with NewStructuredToolHandler - Array output schemas - Schema tags reference - Complete file operations example with structured I/O 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <[email protected]>
|
@ezynda3 I’ve updated tools.mdx with the changes for struct-based schema. Please review when you have a chance. Thanks. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Description
Feat #535
Since we’ve already implemented the output schema with structured content, I’m now working on defining the input schema in a similar style.
We can specify JSON Schema properties directly in our Go struct, such as
requiredenumetc., and then use a helper likemcp.WithInputSchema[WeatherRequest]()to generate the input schema accordingly.This enhancement will help developers maintain MCP services more effectively by enabling a consistent, structured approach to both input and output schemas.
Please help to review. Thanks a lot.
Type of Change
Checklist
MCP Spec Compliance
Additional Information
Summary by CodeRabbit
New Features
Documentation
Tests