An invoice with an unreadable amount waits for its fix at the source

Goal Never write an invoice without an amount, and follow each set-aside line until it is fixed.

An export of supplier invoices carries two mistyped amounts and a test invoice.

the three set aside, as they were read;
the test invoice discarded;
the other two fixed at the source, their letter closed by the right read.

lumnik Open
Purchasing
Data quality
Connector
Entity

invoices-day1.csv

invoice_no,supplier_id,invoice_date,amount_eur
FA-2025-0001,SUP-201,2025-03-03,1310.89
FA-2025-0002,SUP-202,2025-03-03,759.59
FA-2025-0003,SUP-203,2025-03-04,334.76
FA-2025-0004,SUP-204,2025-03-04,355.60
FA-2025-0005,SUP-205,2025-03-05,919.82
FA-2025-0006,SUP-201,2025-03-05,1378.91
FA-2025-0007,SUP-202,2025-03-06,328.89
FA-2025-0008,SUP-203,2025-03-06,933.35
FA-2025-0009,SUP-204,2025-03-07,1709.33
FA-2025-0010,SUP-205,2025-03-07,1771.36
FA-2025-0011,SUP-201,2025-03-08,1431.08
FA-2025-0012,SUP-202,2025-03-08,1556.29
FA-2025-0013,SUP-203,2025-03-09,1.250.00
FA-2025-0014,SUP-204,2025-03-09,828.02
FA-2025-0015,SUP-205,2025-03-10,590.18
FA-2025-0016,SUP-201,2025-03-10,2433.90
FA-2025-0017,SUP-202,2025-03-11,1914.07
FA-2025-0018,SUP-203,2025-03-11,622.31
FA-2025-0019,SUP-204,2025-03-12,342.27

… 22 more lines

manifests/10-invoices.yaml

apiVersion: connectors.lumnik.io/v1kind: Connectormetadata:  name: scenario-invoices-b  connector_type: csv-file  scopes: [invoices-b]spec:  transport:    kind: local    path: /tmp/lumnik-scenario/invoices-dead-letters/b/invoices.csv  parser:    has_header: true  after_process: none  mapping:    on-error:      fields: { amount_eur: dlq }   # an unreadable amount: the invoice goes to the dead letters    row:      - validate-row: { required: [invoice_no, supplier_id] }    cell:      - parse-date: { column: invoice_date, formats: ["yyyy-MM-dd"] }      - parse-number: { column: amount_eur, decimal-separator: "." }

manifests/20-invoice.yaml

kind: Entityname: invoice_blabel: Facture fournisseurdescription: "A supplier invoice received in March 2025. One row is one invoice; the amount excludes VAT."match: [invoice_no]scopes: [invoices-b]columns:  invoice_no:    label: "Numéro de facture"    example: "FA-2025-0001"  supplier_id:    label: "Code fournisseur"    example: "SUP-201"  invoice_date:    label: "Date de facture"  amount_eur:    label: "Montant HT, en euros"sources:  - table: t_scenario_invoices_b    map:      invoice_no: invoice_no      supplier_id: supplier_id      invoice_date: invoice_date      amount_eur: amount_eur

$ lm apply -f 10-invoices.yaml
Applied connector "scenario-invoices-b" — 1 endpoint

$ lm connector run scenario-invoices-b
run scheduled: 2171fb3a-6736-4e53-acf5-a67b7ecc4d20

$ lm run get 2171fb3a-6736-4e53-acf5-a67b7ecc4d20
ID        CONNECTOR            ENDPOINT  STATUS     IN  OUT  SKIPPED  DEAD-LETTERS  STARTED           ENDED
2171fb3a  scenario-invoices-b  default   Completed  41  38   3        3             2026-11-03 17:07  2026-11-03 17:07
⚠ 3 rows quarantined — see: lm dlq list --run 2171fb3a-6736-4e53-acf5-a67b7ecc4d20

$ lm entity apply -f 20-invoice.yaml
Applied entity "invoice_b" → connector."v_invoice_b"

$ lm dlq list --run 2171fb3a-6736-4e53-acf5-a67b7ecc4d20
ID        CONNECTOR            RUN       REASON            ATTEMPTS  RESOLUTION  MESSAGE
98f62ac7  scenario-invoices-b  2171fb3a  MappingFailed     1                     amount_eur: parse-number could not read the value
c88f102c  scenario-invoices-b  2171fb3a  MappingFailed     1                     amount_eur: parse-number could not read the value
7ac70133  scenario-invoices-b  2171fb3a  ValidationFailed  1                     required column 'supplier_id' is missing or blank

$ lm dlq get c88f102c-ae9e-427a-9fd4-9e9e57931560
ID:        c88f102c-ae9e-427a-9fd4-9e9e57931560
Connector: scenario-invoices-b (6ac6b66a-bd57-4331-bf79-25b442fd85a9)
Run:       2171fb3a-6736-4e53-acf5-a67b7ecc4d20
Reason:    MappingFailed
Attempts:  1
Message:   amount_eur: parse-number could not read the value
Detail:    {"field":"amount_eur","message":"parse-number could not read the value"}
Payload:   {"amount_eur":"1.250.00","invoice_no":"FA-2025-0013","supplier_id":"SUP-203","invoice_date":"2025-03-09"}
Resolution: open

$ lm entity get invoice_b --filter invoice_no=FA-2025-0013
no rows

$ lm dlq discard 7ac70133-fc8c-4e42-a112-b21f4ef7c4a3
discarded: 7ac70133-fc8c-4e42-a112-b21f4ef7c4a3

invoices-day2.csv

invoice_no,supplier_id,invoice_date,amount_eur
FA-2025-0001,SUP-201,2025-03-03,1310.89
FA-2025-0002,SUP-202,2025-03-03,759.59
FA-2025-0003,SUP-203,2025-03-04,334.76
FA-2025-0004,SUP-204,2025-03-04,355.60
FA-2025-0005,SUP-205,2025-03-05,919.82
FA-2025-0006,SUP-201,2025-03-05,1378.91
FA-2025-0007,SUP-202,2025-03-06,328.89
FA-2025-0008,SUP-203,2025-03-06,933.35
FA-2025-0009,SUP-204,2025-03-07,1709.33
FA-2025-0010,SUP-205,2025-03-07,1771.36
FA-2025-0011,SUP-201,2025-03-08,1431.08
FA-2025-0012,SUP-202,2025-03-08,1556.29
FA-2025-0013,SUP-203,2025-03-09,1250.00
FA-2025-0014,SUP-204,2025-03-09,828.02
FA-2025-0015,SUP-205,2025-03-10,590.18
FA-2025-0016,SUP-201,2025-03-10,2433.90
FA-2025-0017,SUP-202,2025-03-11,1914.07
FA-2025-0018,SUP-203,2025-03-11,622.31
FA-2025-0019,SUP-204,2025-03-12,342.27

… 21 more lines

$ lm connector run scenario-invoices-b
run scheduled: a458b0b7-cc2d-4fdc-9d8c-cf94fa86ae05

$ lm run get a458b0b7-cc2d-4fdc-9d8c-cf94fa86ae05
ID        CONNECTOR            ENDPOINT  STATUS     IN  OUT  SKIPPED  DEAD-LETTERS  STARTED           ENDED
a458b0b7  scenario-invoices-b  default   Completed  40  40   0        0             2026-11-03 17:07  2026-11-03 17:07

$ lm dlq replayed c88f102c-ae9e-427a-9fd4-9e9e57931560 --new-run-id a458b0b7-cc2d-4fdc-9d8c-cf94fa86ae05
marked replayed: c88f102c-ae9e-427a-9fd4-9e9e57931560

$ lm dlq replayed 98f62ac7-1119-4bda-91e6-90a468aab343 --new-run-id a458b0b7-cc2d-4fdc-9d8c-cf94fa86ae05
marked replayed: 98f62ac7-1119-4bda-91e6-90a468aab343

$ lm dlq list --connector scenario-invoices-b
ID  CONNECTOR  RUN  REASON  ATTEMPTS  RESOLUTION  MESSAGE

$ lm dlq get c88f102c-ae9e-427a-9fd4-9e9e57931560
ID:        c88f102c-ae9e-427a-9fd4-9e9e57931560
Connector: scenario-invoices-b (6ac6b66a-bd57-4331-bf79-25b442fd85a9)
Run:       2171fb3a-6736-4e53-acf5-a67b7ecc4d20
Reason:    MappingFailed
Attempts:  1
Message:   amount_eur: parse-number could not read the value
Detail:    {"field":"amount_eur","message":"parse-number could not read the value"}
Payload:   {"amount_eur":"1.250.00","invoice_no":"FA-2025-0013","supplier_id":"SUP-203","invoice_date":"2025-03-09"}
Resolution: REPLAYED by run a458b0b7-cc2d-4fdc-9d8c-cf94fa86ae05, 2026-11-03 17:07

$ lm dlq get 7ac70133-fc8c-4e42-a112-b21f4ef7c4a3
ID:        7ac70133-fc8c-4e42-a112-b21f4ef7c4a3
Connector: scenario-invoices-b (6ac6b66a-bd57-4331-bf79-25b442fd85a9)
Run:       2171fb3a-6736-4e53-acf5-a67b7ecc4d20
Reason:    ValidationFailed
Attempts:  1
Message:   required column 'supplier_id' is missing or blank
Detail:    {"violations":["required column 'supplier_id' is missing or blank"]}
Payload:   {"amount_eur":"0.00","invoice_no":"FA-TEST-0001","supplier_id":null,"invoice_date":"2025-03-13"}
Resolution: DISCARDED, 2026-11-03 17:07

$ lm entity get invoice_b --filter invoice_no=FA-2025-0013
INVOICE_NO    SUPPLIER_ID  INVOICE_DATE  AMOUNT_EUR  _CONFLICTS
FA-2025-0013  SUP-203      2025-03-09    1250        {}

Limits

on-error applies to CSV connectors; dlq is refused beside split-row.
The hub checks the named run could have carried the row (same connector, completed, later), not that it wrote it.
Synthetic invoices.

Accounting · invoices

Invoices arrive through an export.

Some are mistyped.

41 invoices, two days

The problem

Unreadable amounts.

1.250.00
87.5O, with the letter O.

What is not changed

The ERP stays the reference.

The fix is made at the source.
Nothing is touched up in the hub.

The trap

An invoice written with no amount.

It goes into the totals.
Nobody looks for it.

What had to be written

on-error: { fields: { amount_eur: dlq } }

One line.

The invoice waits, with its line as read.
Nothing vanishes on the way.
A 45-line scenario, two manifests.

The next day

The amounts fixed in the ERP.

40 invoices, all with an amount.
No letter left open.

The limit

For CSV connectors.

on-error: dlq is refused beside split-row.

Try it

The scenario replays locally.

Every step is published with its output.

This scenario runs on lumnik Open, free and open source.

Try lumnik Open →