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GET
Read the weekly change series of a ZIP
One ZIP’s change series: a row per week with the metrics you asked for, plus the totals over the window. It is the parcel history of GET /v1/properties/{property_id}/history, counted across every parcel in the ZIP instead of one.

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Use it when

You need a market pulse: the turnover of this ZIP against last quarter, a rise in price cuts, a move in delinquency. The route answers in the week grain of the recorded events, so two weeks are always comparable.

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The metrics

metrics picks the series. If you leave it out, the route returns every series. Each metric is a count of events of that kind in the week, over the parcels of the ZIP: avm_change_median_pct is the only metric that is not a count. It is the median move in percent among the parcels whose valuation changed that week. So a week where nothing moved has no median, not a zero. In totals, the route sums every count over the window and averages that one metric.

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Read the week grid

  • weeks[] is oldest first, one entry per replayed weekly file. first_week and last_week are the edges of the returned window: weeks[0] and the last entry. The lake’s own edges are meta.coverage[].parcel.history.first_week and last_week. weeks_applied is the window that the route applied: what you asked for, or the plan’s cap on Free and Starter. The gotcha below has the cap. weeks[] holds at most that many entries, or fewer when the lake has fewer weeks for the ZIP.
  • file_kind is FULL or DELTA. Read parcels_observed against it. parcels_observed counts the rows of this ZIP in that week’s file. On a full delivery that is every parcel of the ZIP. On a delta it is only the changed parcels. It is a measure of what the delivery contained, never a denominator for a rate.
  • n_events is every event of the week. It also counts the kinds you did not ask for in metrics.
  • A week missing from the series is a week with no delivery. The replay interpolates nothing across it. The events seen afterwards carry the date of the first file that followed.

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Gotchas

  • Send zip. It must be one of meta.coverage[].parcel.history.zips for the market. Any other ZIP answers 422 history_unavailable, which names the covered ZIPs. Counties, cities and ZIP codes lists them.
  • The financing and valuation metrics come from the dated snapshot. If you ask for them, the response carries a meta.dated[] entry. new_mortgages and lien_releases stop at meta.coverage[].parcel.financing.as_of for that reason. A flat tail after that date is the delivery, not the market. See dated data.
  • On Free and Starter, the series is 52 weeks at most. Here the route lowers a larger weeks to the cap, and weeks_applied says so. Over /mcp, a weeks above the cap on those plans answers 403 plan_limit, which names the cap instead of a clamp. See Plans and limits.
  • The route answers 404 not_found when the market code matches no loaded market. It answers 422 parcels_unavailable when the loaded market has no parcel tables.

Authorizations

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Authorization
string
header
required

API key from the developer console (starts with zpka_). Create one at https://developers.investorlift.com/get-a-key.

Path Parameters

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market
string
required

Market code, for example phx.

Required string length: 1 - 16

Query Parameters

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zip
string
required

The ZIP code. It must be one of meta.coverage[].parcel.history.zips.

Pattern: ^\d{5}$
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weeks
integer
default:52

How many of the newest weeks to return (default 52, at most 160). Over 52 on Free and Starter, the API clamps the series to 52 over REST and data.weeks_applied says so. Over /mcp the API refuses that request by name (403 plan_limit).

Required range: 1 <= x <= 160
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metrics
enum<string>[]

Which series to return (comma list or repeated key). Default: every metric.

Minimum array length: 1

A weekly series: event counts per kind, the median AVM move in percent among parcels whose AVM moved, or permits issued.

Available options:
owner_changes,
listings,
relists,
price_cuts,
price_rises,
solds,
delists,
vacancy_onsets,
vacancy_cleared,
delinquency_onsets,
delinquency_cured,
new_mortgages,
lien_releases,
involuntary_liens,
assessment_changes,
avm_changes,
structure_changes,
portfolio_changes,
avm_change_median_pct,
permits_issued

Response

The weekly change series.

The weekly change series.

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data
object
required

GET /v1/markets/{market}/changes: the weekly change series of one ZIP.

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meta
object
required

Response metadata: when the API produced it, which markets it covers, and how fresh they are.