Developer & data · focused workspace

JSON As-of Record Joiner

Attach the latest eligible reference record to each event using an exact entity key and timestamp, with an optional lookback limit.

Match auditEditable projectsLocal processing

Source → inspect → export

Open project

Preparing the worked example…

Your source & settings

Settings & options

Open your media file

Files stay in your browser. Try the built-in sample first.

Choose file

Source text is limited to 1.5 million characters per editor; imported text files are limited to 1.5 MB.

Inspect your result

PREVIEW & EXPORT

Output file

Know what changed

Backward as-of join only. Exact entity keys and explicit timestamp offsets are required. Same-key, same-time references are rejected rather than chosen arbitrarily.

Choose another output above or open Export files.

Explore the example

Attach the latest eligible reference record to each event using an exact entity key and timestamp, with an optional lookback limit.

What you can inspect

Match audit — Row, Entity, Matched, Age hours.

Keep the result you need

Use the output selector to inspect each generated file, then download it. Save a project to keep source inputs and settings together. Result files and editable projects serve different purposes.

Processing & file support

Source text is limited to 1.5 million characters per editor; imported text files are limited to 1.5 MB.

Your working session

Processing runs locally in a worker with a 30-second cancellation limit. Undo and redo keep up to 20 edits in this tab. Project files include imported assets and are limited to 40 MiB. There is no automatic saving.

Public pages include advertising and optional analytics under our privacy policy. Review the method and any flagged output before sharing files.

Using JSON As-of Record Joiner

Attach the latest eligible reference record to each event using an exact entity key and timestamp, with an optional lookback limit.

Start with the worked example in events and reference history, then paste your own source or open a text file.
Adjust entity key path, timestamp path, maximum lookback hours · 0 = unlimited. Change one setting at a time so you can understand its effect.
Choose “Process source”. Inspect the match audit before using the result.
Download the selected output, inspect other files in Export files and save a project if you want to reopen the same inputs.

Example

Try the built-in example, inspect match audit and compare the result after changing one option.

Questions & answers

What does JSON As-of Record Joiner do?

Attach the latest eligible reference record to each event using an exact entity key and timestamp, with an optional lookback limit.

What are the important limitations?

Backward as-of join only. Exact entity keys and explicit timestamp offsets are required. Same-key, same-time references are rejected rather than chosen arbitrarily.

Can I save and reopen my work?

Yes. Save a project JSON file containing your inputs, settings and any imported assets. Projects are limited to 40 MiB. Undo/redo stores up to 20 edits in this session and is not saved in the project. There is no automatic saving.

How do imports and output previews work?

Source text is limited to 1.5 million characters per editor; imported text files are limited to 1.5 MB. Text previews show up to 150,000 characters; downloads include the complete output. Tables show 50 rows per page; CSV files include all rows.