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fix(mcp): handle null tools field in MCP server configs - #1960
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This PR makes the tools list in MCP server configs more tolerant/optional by normalizing null to an empty list in Python and omitting empty tools fields from JSON in Go.
Changes:
- Add Pydantic
field_validatorto coercetools: nullinto[]for both HTTP and SSE MCP server configs. - Update Go JSON tags to
omitemptyfortoolsin HTTP and SSE MCP server configs.
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Copilot reviewed 2 out of 2 changed files in this pull request and generated 5 comments.
| File | Description |
|---|---|
| python/packages/kagent-adk/src/kagent/adk/types.py | Coerces tools from null to [] via Pydantic validators. |
| go/api/adk/types.go | Omits tools from JSON when empty to align with optional semantics. |
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Makes sense to me, needs to resolve conflicts now
When tools is omitted from an MCP server config, the Go side serializes it as null, which causes a pydantic ValidationError on the Python side because the field expects list[str]. Add omitempty to the Go JSON tags so null is never sent, and add a field_validator in Python to coerce null to an empty list. Fixes #1797 Signed-off-by: mesutoezdil <[email protected]>
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kagent 0.9.6 Created-by: HarmonybrewBot Commit-by: HarmonybrewBot Merged-by: HarmonybrewBot Description: Created by `brew bump` --- Created with `brew bump-formula-pr`.<details> <summary>release notes</summary> <pre><!-- Release notes generated using configuration in .github/release.yml at v0.9.6 --> ## What's Changed ### Features * feat(mcp): expose agents as MCP resource with change notifications by @onematchfox in kagent-dev/kagent#1856 * feat(adk): propagate parent + root context_id headers on outbound A2A calls by @Prefix in kagent-dev/kagent#1927 ### Bug Fixes * fix(compaction): preserve namespaced tool names in LLM summarizer prompt by @yashrajshuklaaa in kagent-dev/kagent#1907 * fix: preserve Ollama streaming tool calls by @andreivince in kagent-dev/kagent#1948 * fix(bedrock): preserve thinking blocks in multi-turn tool use by @mesutoezdil in kagent-dev/kagent#1873 * fix(translator): forward Anthropic config fields to model config by @mesutoezdil in kagent-dev/kagent#1962 * fix(openai): apply ReasoningEffort in applyOpenAIConfig by @mesutoezdil in kagent-dev/kagent#1959 * fix(mcp): handle null tools field in MCP server configs by @mesutoezdil in kagent-dev/kagent#1960 ### Documentation * docs(api): add field descriptions for BYO agent spec by @marians in kagent-dev/kagent#1969 ### Other Changes * Fix/1945 fix for wrong validation being triggered by @gauravshinde1729 in kagent-dev/kagent#1946 * openclaw substrate support by @peterj in kagent-dev/kagent#1939 * chore(deps): bump the npm-minor-patch group in /ui with 14 updates by @dependabot[bot] in kagent-dev/kagent#1951 * Link fixes by @kristin-kronstain-brown in kagent-dev/kagent#1950 * RemoteMCPServer TLS + companion-Secret API + plaintext egress rewrite by @iplay88keys in kagent-dev/kagent#1905 ## New Contributors * @yashrajshuklaaa made their first contribution in kagent-dev/kagent#1907 * @andreivince made their first contribution in kagent-dev/kagent#1948 * @kristin-kronstain-brown made their first contribution in kagent-dev/kagent#1950 * @Prefix made their first contribution in kagent-dev/kagent#1927 * @marians made their first contribution in kagent-dev/kagent#1969 **Full Changelog**: https://github.com/kagent-dev/kagent/compare/v0.9.5...v0.9.6</pre> <p>View the full release notes at <a href="https://github.com/kagent-dev/kagent/releases/tag/v0.9.6">https://github.com/kagent-dev/kagent/releases/tag/v0.9.6</a>.</p> </details> <hr> See merge request: Harmonybrew/homebrew-core!10637
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When tools is omitted from an MCP server config, the Go side serializes it as null. This causes a pydantic ValidationError on the Python side because the field expects list[str].
Fix: add omitempty to the Go JSON tags so null is never sent, and add a field_validator in Python to coerce null to an empty list.
Fixes #1797