fix(mcp): sync User-Agent version with package.json and add CLI validation tests

[aptsalt]

Summary

• Bug fix: userAgent.ts hardcoded VERSION = '0.3.1' but package.json is at 0.3.3, causing the User-Agent header to report an incorrect version to Stripe servers
• Test coverage: Added missing tests for validateApiKey, validateStripeAccount, and --tools deprecation handling

Changes

• tools/modelcontextprotocol/src/userAgent.ts: Sync hardcoded version to 0.3.3 (with comment to keep in sync with package.json)
• tools/modelcontextprotocol/src/test/index.test.ts: Add 6 new test cases covering validateApiKey (4 cases), validateStripeAccount (2 cases), and --tools deprecation (1 case)

Test plan

• Existing tests pass
• New validation tests cover edge cases
• User-Agent string now reports correct version

Related: Noticed during version bump in #330

[cla-assistant]

All committers have signed the CLA.

[matv-stripe]

can we use the VERSION constant exported here https://github.com/stripe/ai/blob/main/tools/typescript/src/shared/constants.ts#L8 ?

[aptsalt]

Good call! I looked into importing from tools/typescript/src/shared/constants.ts but since @stripe/mcp is a separate package (no dependency on the typescript toolkit), that import won't resolve.

Two options I see:

1. Enable resolveJsonModule + import from own package.json — but rootDir: "./src" in tsconfig blocks importing ../package.json. Would need to adjust rootDir or add a build-time injection like tsup does for the shared package.

2. Replicate the shared pattern — use process.env.PACKAGE_VERSION and inject it at build time via the build script.

Which approach do you prefer? Happy to implement either. Option 2 seems most consistent with how the shared toolkit already handles it.

[matv-stripe]

i like option 2! thank you!

[aptsalt]

Done! Just pushed the implementation. userAgent.ts now reads from process.env.PACKAGE_VERSION which gets injected at build time by scripts/inject-version.js same pattern the shared toolkit uses via tsup's define. No more manual version syncing. All tests pass.

[matv-stripe]

thank you @aptsalt , left a small comment

[aptsalt]

Implemented Option 2! Here's what the new commit does:

src/userAgent.ts — Replaced hardcoded version with:

const VERSION = process.env.PACKAGE_VERSION || '0.0.0-development';

scripts/inject-version.js — Post-tsc build step that reads version from package.json and replaces process.env.PACKAGE_VERSION in the compiled dist/userAgent.js with the actual version string. This mirrors how the shared toolkit handles it via tsup's define option.

package.json — Updated build script:

tsc && node scripts/inject-version.js && node -e "require(\"fs\").chmodSync(\"dist/index.js\", \"755\")"

jest.setup.ts + jest.config.ts — Sets PACKAGE_VERSION env var during tests so the version resolves correctly.

All 24 tests pass ✅, build injects version correctly ("0.3.3" baked into dist output).