Sync Conflict Resolution
Decide what happens when your app and an external system disagree.
What it adds
Detection and human resolution of divergence between a local record and its counterpart in a synced external system.
What your agent is told to do
6
What your agent is told to do
6-
1
Write down the source-of-truth policy per field or per object before building anything: app wins, external wins, or a human decides. An implicit policy becomes silent data loss.
-
2
Detect divergence by comparing stored versions or change timestamps from both systems against the last synced snapshot. Last-write-wins on arrival order is not detection; it is overwriting.
-
3
When a human must decide, show both values side by side and state the consequence of each choice, including what will be pushed to the external system.
-
4
Support field-level resolution where the object allows it, so choosing a local phone number does not also revert an externally-updated address.
-
5
Stamp each resolution with the versions it settled, and make later sync jobs carrying older versions no-ops. Do NOT let a queued stale job reopen a conflict a user already resolved.
-
6
Two users saving the same record in your app is a different problem, owned by Edit Conflict Detection, which limits itself to the moment of writing. Do not re-implement its version-token mechanics here.
Edge cases it handles
6
Edge cases it handles
6- The external system may not expose a version or reliable modified timestamp. Fall back to hashing the fields you care about and say so in the policy.
- Clock skew between systems makes timestamp comparison unsafe near the boundary. Prefer versions; when using time, require a meaningful margin.
- A record deleted on one side and edited on the other is a conflict, not a delete. Never propagate a destructive action as the automatic resolution.
- Conflicts arrive in bulk after an outage. Offer a reviewed bulk resolution by policy rather than making someone click through hundreds.
- Resolution must be auditable — who chose which side, when, and what the discarded value was. Someone will ask.
- While a conflict is unresolved, the record must be visibly flagged, and syncing that field must pause instead of quietly picking a winner.
Definition of done
8
Definition of done
8- A source-of-truth policy exists per synced object or field and is documented in the app.
- Conflicts are detected by version or timestamp comparison against a last-synced snapshot.
- The resolution UI shows both values and states what each choice will do.
- Field-level resolution is possible where the object supports it.
- A stale sync job cannot reopen or reverse a resolved conflict.
- Every resolution records the chooser, the time, and the discarded value.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
Contentful Entry Sync
Contentful Entry Sync
Create and update Contentful entries against the connected space, environment, and locale.
What it does
A sync that writes app records into Contentful entries using the connected space's content model and locale configuration.
How it works
- 1 Have the operator select the space, the environment, and the default locale during connection, and store all three, because writing production content into a sandbox environment is an easy and expensive mistake.
- 2 Fetch the content model at connection time and again before each sync run, map app fields to entry fields by their stable identifiers, and validate the value type against the model before attempting the write.
- 3 Write every localized field under an explicit locale rather than relying on whatever the space treats as default, and state clearly which locales the app owns and which it leaves to editors.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/contentful-entry-sync
Typesense Index Sync
Typesense Index Sync
Keep a search index in step with your records so results stay current and correctly scoped.
What it does
A one-way sync from the app's records into a Typesense collection, with server-enforced tenant filtering and a rebuild path.
How it works
- 1 Identify every model users search today and declare the indexed shape explicitly: the fields people type into, the fields they filter and sort on, and nothing more. Treat a missing or newly added field as absent rather than letting the document fail validation.
- 2 Reuse the app's existing background-job system to push creates, updates, and deletes. Do not index inside the request cycle; a slow or unreachable search service must never make a save fail or hang.
- 3 Build the tenant, workspace, and permission filter on the server at query time and attach it to every search. Do not accept a filter, collection name, or scope value from a client-supplied parameter, because anything the browser can set the browser can change.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/typesense-index-sync
Mapbox Geocoding
Mapbox Geocoding
Convert typed locations into coordinates and structured addresses the app can use.
What it does
Forward and reverse geocoding with confirmed matches, controlled result bias, and coordinate precision rules.
How it works
- 1 Separate the two directions explicitly: text to coordinates for entry and search, coordinates to address for a dropped pin or a device location. They take different inputs, carry different confidence, and fail differently.
- 2 Present ambiguous matches as a list the user confirms. Silently taking the first result is how a record ends up in the wrong country with nobody noticing for months.
- 3 Bias results toward a location only when the app genuinely knows one, such as a workspace address or the map viewport the user is already looking at.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/mapbox-geocoding
How it works
-
1
Copy the link
Grab the Markdown instruction URL for this feature.
-
2
Give it to your AI
Paste it into Claude Code, Cursor, v0, Lovable — whatever you build with.
-
3
It inspects, then implements
Your agent reads your existing app first, then adds the feature to fit it.
Works with your stack
These instructions are written to adapt. They tell the agent to detect your framework, match your existing design system, and reuse what you already have — rather than assuming a particular stack.
Need it tighter than that? Customize the feature and tell it exactly what you're running.