What Discovery solves
Manual file uploads create friction at every step. Teams export files, transfer them, monitor for failures, and re-upload when something goes wrong. This process is time-consuming, error-prone, and breaks when data volume grows. Discovery replaces the manual pipeline. It connects to external systems through Fetcher, detects available data sources automatically, and pulls transactions into Matcher on demand. When a new data source appears — a new bank connection, a new payment processor — Discovery finds it without reconfiguration.
How Discovery works
Discovery operates through Fetcher, Lerian’s data ingestion service. Fetcher manages connections to external systems: databases, APIs, file stores, and banking platforms. Discovery exposes those connections to Matcher and coordinates the extraction process. The workflow has seven steps:
- Check status — Confirm Fetcher is connected and Discovery is available.
- Browse connections — See all data sources Fetcher has access to.
- Inspect a connection — Review the schema to understand what fields are available.
- Test a connection — Validate the connection before committing to an extraction.
- Create an extraction — Request that Matcher pull data from a specific source.
- Monitor progress — Track extraction status as data flows in.
- Refresh connections — Rescan when new data sources are added.
Discovery workflow
Check Discovery status
Verify that Fetcher is connected and Discovery is operational before starting.Browse connections
List all data sources available through Fetcher.Inspect a connection
Review the schema of a specific connection to understand what data fields are available before extracting.Test a connection
Validate that Matcher can reach and read from a connection before creating an extraction.Create an extraction
Request that Matcher pull transaction data from a specific connection into the current context.Monitor extraction progress
Track the status of an active extraction. For large datasets, use the poll endpoint to check progress incrementally.pending → running → completed (or failed). The response includes a count of records extracted and any errors encountered.
Refresh available connections
When new data sources are added to Fetcher, trigger a refresh so Discovery picks them up.Best practices
Always test connections before extracting
Always test connections before extracting
A failed extraction mid-run is harder to recover from than a failed test. Test every connection before creating an extraction — especially when connecting to a new source or after a credential rotation.
Inspect schemas before mapping fields
Inspect schemas before mapping fields
Field names vary across systems. A bank might call the transaction date
value_date while your ledger uses posting_date. Check the schema before configuring field mappings to avoid silent mismatches.Monitor extractions actively for large datasets
Monitor extractions actively for large datasets
Large extractions take time. Don’t assume completion — poll the extraction status and confirm the record count before starting a match run. Starting a run on incomplete data generates incorrect exceptions.
Refresh connections when sources change
Refresh connections when sources change
Discovery doesn’t scan for new connections automatically. When a new payment processor is added or a new database is onboarded to Fetcher, trigger a refresh. Otherwise, Discovery won’t show the new source.
Scope extractions to the reconciliation period
Scope extractions to the reconciliation period
Use date range parameters to extract only the data relevant to the current reconciliation period. Extracting unbounded data increases processing time and may pull records that belong to already-closed contexts.
Next steps
External sources
Configure the external data sources that Discovery connects to.
Field mapping
Map fields from extracted data to Matcher’s transaction model.
Discovery API reference
Full API reference for Discovery endpoints.

