# Prisma v8.0.0-rc.21 — Release & Upgrade Intelligence
- **Product:** Prisma (https://prisma.io)
- **Version:** v8.0.0-rc.21
- **Released:** Oct 30, 2026
- **Impact Score:** 7/10
- **Breaking Changes:** Source flagged
- **Canonical Analysis:** https://changelogs.us/prisma/updates/v8.0.0-rc.21/

## Executive Summary (TL;DR)
Prisma v8.0.0-rc.21. Source highlight: `migration plan` and `db update` can rename or delete an enum value on Postgres and SQLite, and update the rows that hold it. MongoDB contracts written in TypeScript, PSL or Prisma 6 now build through one builder and follow the same rules. A closed client's members report the failure through the pro

## Breaking Changes & Deprecations
- The upgrade recipes for this hop: the [app recipe](https://github.com/prisma/orm/blob/v8.0.0-rc.21/skills/prisma-8/upgrading/app/upgrades/8.0.0-rc.20-to-8.0.0-rc.21/) and the [extension recipe](https://github.com/prisma/orm/blob/v8.0.0-rc.21/skills/prisma-8/upgrading/extension/upgrades/8.0.0-rc.20-to-8.0.0-rc.21/). Each breaking change below names the change ids to look for in them. After upgrading, run `prisma contract emit` once, so a contract that an extension such as Supabase stamps with its version matches the installed package (`contract-artifacts-restamp` in the app recipe).
- Breaking changes - **A client member that returns a promise or a result rejects instead of throwing at the call.** On `postgres()`, `sqlite()`, a `supabase()` role-bound client and a transaction, `query`, `execute`, `prepare`, `transaction`, ORM calls and a prepared statement's `query` and `execute` now report a closed client, a failed connection or an ended transaction through what they return. The promise rejects, or the result rejects when it is awaited or read. Error codes and messages do not change. So `.catch(handle)` and `Promise.allSettled` now see the error, but a `try`/`catch` around

## New Features
- **A client member that returns a promise or a result rejects instead of throwing at the call.** On `postgres()`, `sqlite()`, a `supabase()` role-bound client and a transaction, `query`, `execute`, `prepare`, `transaction`, ORM calls and a prepared statement's `query` and `execute` now report a closed client, a failed connection or an ended transaction through what they return. The promise rejects, or the result rejects when it is awaited or read. Error codes and messages do not change. So `.catc
- `migration plan` and `db update` can rename or delete an enum value on Postgres and SQLite. `--rename Status.ARCHIVED:Status.RETIRED` changes the stored value in every column and list that holds it, and `--delete Status.ARCHIVED` sets it to NULL in optional columns and takes it out of lists. On a required column that still holds the value, the apply stops before changing anything and says how to keep the data. `migration.ts` gains `this.replaceStoredValue` and `this.removeStoredValue`. (#30849)
- MySQL has its first public packages, `@prisma/orm-mysql` and `@prisma/orm-target-mysql`, as an early preview. They can emit a contract, and `migration plan`, `db migrate`, `db verify` and `db sign` work against MySQL 8.4 for creating and dropping tables, columns, indexes, unique constraints and foreign keys. Other schema changes are refused with a message that they are not supported on MySQL yet, and queries are not available yet. The new `prisma-8-demo-mysql` example shows the workflow. (#30841
- A failed migration on a target whose schema changes cannot be rolled back, such as MySQL or MongoDB, says which contract space failed and what stayed applied. Running `db migrate` again skips what was applied and finishes the rest. (#30841)
- A contract source's warnings now reach `contract emit`, `contract print` and the control client even when the source then fails. Before, they were dropped. (#30846)
- PostgreSQL has three new explicit date and time types: `TimestampJsDate(p?)` reads a `timestamp` column as a JavaScript `Date`, `TimestampInstant(p?)` reads it as a `Temporal.Instant`, both as UTC, and `IntervalString(p?)` reads an `interval` as an ISO 8601 duration such as `P1Y2M`. `DateTemporal` and `TimeTemporal` are added as the explicit names of what `Date` and `Time` read today. An enum on `TimestampString`, `TimestamptzString` or `Timetz` is now allowed. (#30834)

## Bug Fixes
- When a database's marker names a contract that no migration starts or ends at, for example after a migration it applied was deleted or planned again, `db migrate` fails with `MIGRATION.MARKER_MISMATCH` and now says why: the last contract of the migration graph the database reached, and the migrations it applied after that which are no longer on disk or were planned again. Its next actions give two recoveries that work: `db update`, for a database whose migration history does not need to be kept,
- The upgrade guides and scripts for rc.18 → rc.19 and rc.19 → rc.20 now work on real projects, so users who upgrade from rc.18 or rc.19 get working guides through `prisma skills sync`. The main fixes: (#30855)
- Every script skips hidden directories, such as `.next/` and other worktrees.
- `contract-from-json` moves a client call whose result is destructured.
- `remove-nocheck` rewrites stored PostgreSQL defaults into the rc.19 form, and takes `--default` for a default it cannot convert.
- Both guides say how to recover a database that is behind on migrations: `prisma db sign --contract <last applied migration>`, then `prisma db migrate`.