## Summary
The `GraphQL and OpenAPI Breaking Changes Detection` workflow has been
posting graphql-inspector stack traces as PR comments — see [#20445
comment](https://github.com/twentyhq/twenty/pull/20445#issuecomment-4421142635)
for an example.
### Root cause
- The wait step probed readiness with `curl -s URL > /dev/null 2>&1`,
which exits 0 for **any** HTTP response — including 5xx and GraphQL
error JSON. NestJS opens the HTTP listener before the workspace schema
cache is fully populated, so the wait often completed while the server
still served auth/metadata error JSON.
- The introspection download therefore wrote a small (~154-byte) error
payload instead of the real schema. `jq empty` in the validation step
only checks JSON *syntax*, so `{"errors":[...]}` passed validation.
- `graphql-inspector diff` then failed with `Unable to read JSON file:
... Not valid JSON content`, the workflow swallowed the error into the
diff markdown, and the bot posted that stack trace verbatim on the PR.
In the failing run, the main-branch files were 154 B (GraphQL) and 112 B
(REST 500); the current-branch files in the same run were 600 KB–2.8 MB.
### Fix
- Wait steps now POST an authenticated introspection (`{ __schema {
queryType { name } } }`) and require `.data.__schema` plus a 2xx
response from `/rest/open-api/core` (`curl -f`) before declaring the
server ready.
- Validation step now checks for the expected shape (`.data.__schema`
for GraphQL, `.openapi`/`.swagger` for OpenAPI) and includes the first
200 bytes of any bad payload in the warning, so when something genuinely
goes wrong the next debugger has a real lead instead of a generic stack
trace.
## Test plan
- [ ] CI runs against this branch — the workflow's own readiness probes
are now exercised against the real server, so a green run validates the
new check.
- [ ] If the readiness probe still passes but downloads regress, the
strengthened validation step will surface the payload in the workflow
logs instead of posting a graphql-inspector stack trace on the PR.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
