This page is Mnemom’s canonical commitment for how the API evolves. It is the contract we expect every customer integration to be able to rely on. For how-to detail, see the API Versioning guide.Documentation Index
Fetch the complete documentation index at: https://docs.mnemom.ai/llms.txt
Use this file to discover all available pages before exploring further.
The two version axes
Mnemom versions the API at two independent levels:| Axis | Where it lives | When it changes | What it gates |
|---|---|---|---|
| URL generation | /v1/ prefix in every path | Only for complete API redesigns. Expected cadence: at most once every several years. | The shape of the surface — paths, resource hierarchy, top-level abstractions. |
| Date-pinned behavior | X-Mnemom-Version: YYYY-MM-DD request/response header | Each breaking change inside a /v1/-generation | Field names, response shapes, default behavior, enum values, validation rules. |
X-Mnemom-Version date never moves the URL; a new URL generation does not invalidate active date-pinned integrations.
This dual model mirrors Stripe-Version and GitHub’s X-GitHub-Api-Version. Per the ADR-042 amendment (Q2 ratification 2026-05-08), X-Mnemom-Version is the 7th Mnemom-namespaced header and is permanent contract.
How clients pin a version
Production integrations must pin by sending theX-Mnemom-Version header on every request:
Support window
| Change class | Minimum support window | Notes |
|---|---|---|
| Standard breaking change | 18 months from the new version’s release date | Longer than most APIs (typical industry standard is 12). The premium reflects Mnemom’s service to the agentic internet: an agent in production may not be able to update on a human cadence. |
| Security-critical change | 30 days minimum | Rare; only when continued support of the old behavior would create a customer-facing security exposure. We notify and assist migration on an accelerated path. |
| Enterprise / contract terms | Per contract | Some enterprise contracts negotiate longer windows. |
Sunset header and a link to the migration guide. There is no silent re-mapping past retirement — the surface is final.
What counts as a breaking change
A change is breaking (requires a new version date) if any of:- A response field is removed or renamed.
- A response field’s type changes.
- A previously optional request field becomes required.
- An enum loses a value, or an enum’s set of valid values is constrained.
- An endpoint is removed.
- A default behavior changes in a way client code could observe.
- A new endpoint is added.
- A new optional response field is added.
- A new optional request parameter is added.
- An enum gains a new value.
- A new response header is introduced.
protobuf / Stripe-Version-style ecosystems require. Tooling that fails closed on additive evolution is brittle.
Deprecation signals
When a version is deprecated, calls to that version surface:Sunset) and draft-ietf-httpapi-deprecation-header (Deprecation).
In parallel, we send email notifications to the org owner and to any integration contacts on file at:
- T+0 — deprecation announcement.
- T+12 months — half-window mark.
- T+16 months — 60-day warning.
- T+17 months — 30-day final warning.
What we will not do
- We will not break date-pinned production behavior within
/v1/without bumping the date. - We will not retire a version before the published
Sunsetdate. - We will not silently change
X-Mnemom-Versionresolution behavior. The fallback rule (closest valid predecessor) is part of the contract. - We will not introduce a
/v2/URL generation for individual breaking changes. URL increments are reserved for resource-model overhauls.
Related
- API Versioning guide — integration how-to, SDK pinning, working examples.
- API Reference overview — base URL, auth, the version table.
- Migration guides — version-cutover walkthroughs as they’re published.
- ADR-042 — Header Rationalization — the architectural decision that locked
X-Mnemom-Versionas canonical, post-2026-05-08 amendment.