Task: Skill — MongoDB Upgrade Path (v6 → Prisma Next)

Overview

A prisma-mongodb-upgrade skill in prisma/skills for the one user cohort with no road into Prisma 7 at all: MongoDB users. Prisma 7 does not ship a MongoDB connector and never will — v6 is the last classic-ORM major that supports MongoDB, and the supported future is Prisma Next (the v8 lineage, currently Early Access). An agent that does not know this will either recommend an upgrade that cannot work or silently rewrite an app onto a SQL database. The skill gives agents the correct decision framing and the concrete migration mechanics.

Content outline

Decision framing first

• The version landscape: v6 = terminal major for MongoDB on the classic ORM; v7+ = no MongoDB; Prisma Next = the MongoDB future. prisma-upgrade-v7 explicitly does not apply to MongoDB projects — cross-link both ways so agents route correctly from either entry point.
• Migrate now vs stay on v6 for the time being: Early Access maturity, feature-parity check against the app's actual usage, production risk appetite. Staying is a legitimate outcome — include stay-on-v6 hygiene (pin versions, track advisories, revisit cadence).

Migration mechanics (v6 → Next)

• Schema: schema.prisma with the mongodb provider (@db.ObjectId, composite/embedded types, @@index on collections) → Prisma Next's type-safe contract; a mapping table for models, embedded documents, indexes, and defaults.
• Config: v6 datasource URL / env loading → Next's config surface (prisma-next.config.ts).
• Client API: query-surface mapping for CRUD, filters, relation-style queries over references, and the raw escape hatches ($runCommandRaw, findRaw, aggregateRaw) — what the Next equivalents are, or how to bridge where none exists yet.
• Migrations story: v6 MongoDB never had prisma migrate (only db push and index sync); Next has a real contract-driven flow (emit / verify / sign / migrate). What that changes operationally.
• Data: none moves — same database, same collections; the ORM layer changes. Verification checklist: indexes match, reads/writes round-trip on a staging copy before cutover.

Hand-off and freshness discipline

• After the switch, the project should run prisma-next init's own skill installation; this skill is the discovery bridge that lives where v6 users look (prisma/skills), not a duplicate of prisma-next's upgrade cluster — link to it as the authoritative, always-latest continuation.
• Verify-before-acting: Next is Early Access and its surface moves; the skill instructs agents to check the installed prisma-next version and its shipped skills before composing commands from memory, and states which Next version the skill's own content was verified against.

Scope

• prisma/skills: new prisma-mongodb-upgrade skill directory (SKILL.md + references/ per repo conventions). Cross-links added in prisma-upgrade-v7 ("MongoDB? This guide does not apply — see prisma-mongodb-upgrade") and prisma-database-setup.
• Content must be authored against the then-current prisma-next MongoDB support surface — grounding in the prisma-next repo is a prerequisite step, not an afterthought.

Acceptance criteria

• An agent asked to "upgrade this Prisma + MongoDB app to the latest Prisma" correctly rules out v7, presents the v6-stay vs Next-migrate decision with honest Early Access caveats, and can execute the Next path end-to-end from the skill.
• prisma-upgrade-v7 no longer leaves MongoDB users without a route (cross-link in place).
• The skill states the prisma-next version its content was verified against.

Open questions

• Deduplication boundary with prisma-next's own upgrade skill cluster (which always tracks main): proposed split — this skill owns discovery + decision framing + v6-side preparation; the prisma-next cluster owns the Next-side specifics. Confirm with the prisma-next maintainers.
• Whether MongoDB support in Next is complete enough today for a "migrate now" recommendation, or the skill should initially lead with stay-on-v6 guidance — resolve by grounding against prisma-next's current state when authoring.