chore: Pin @modelcontextprotocol/sdk to exact 1.29.0#789
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Recent SDK upgrade from 1.25.2 to 1.29.0 happened transitively (via @modelcontextprotocol/ext-apps@1.7.0 peer dep ^1.29.0) without an explicit version-bump diff, shipping a behavior change in WebStandardStreamableHTTPServerTransport (now calls onerror on previously-silent 4xx paths) that surfaced as new [MCP Error] log spam in prod. Pin the direct dep to exact 1.29.0 and add overrides so transitive peer deps cannot bump it. Future bumps require an explicit edit and PR review. No runtime change: lockfile was already resolving to 1.29.0; only the npm semver range narrows.
jirispilka
approved these changes
May 5, 2026
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Context
Recent SDK upgrade from 1.25.2 → 1.29.0 happened transitively in #770 via
@modelcontextprotocol/ext-apps@1.7.0, whose peer dep tightened to^1.29.0. There was no explicit version-bump commit, so the change wasn't visible in PR review.The new SDK ships a behavior change in `WebStandardStreamableHTTPServerTransport` (SDK PR #1580, released in v1.27.1): previously-silent 4xx paths now call `transport.onerror`, which surfaces as new `[MCP Error]` log spam in production. Already mitigated for the SSE-conflict case in #787.
Solution
Pin `@modelcontextprotocol/sdk` to exact `1.29.0` and add an `overrides` entry so transitive peer deps can't bump it. Future SDK bumps now require an explicit, reviewable edit.
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