Blocker — neon-http transaction trap

Symptom

db.transaction(async (tx) => { ... }) on a connection created via drizzle({ schema, ... }) over the neon-http driver throws NeonDbError: ... at runtime. Test mocks may pass; production fails.

Cause

The neon-http driver is request-scoped (one HTTP round-trip per query); transactions require a stateful TCP connection. The driver does not support BEGIN/COMMIT sequencing.

Fix

Use db.batch([...statements]) to atomically commit a fixed list of statements in one round-trip:

await db.batch([
  db.insert(schema.projects).values({ ... }),
  db.insert(schema.transitions).values({ ... }),
]);

If you need a dependent ID across statements, pre-generate UUIDs in application code rather than relying on RETURNING from the first statement.

Reference

• Cross-project playbook: ~/.claude/playbooks/drizzle-orm.md
• Hard constraint in workspace CLAUDE.md