Nexus

Reconciliation by API

Ingest data from any source, define matching rules and receive every result by signed webhook.

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Nexus

Bank x ERP reconciliation

transacoes_banco_x × notas_erp

completed

decision_counts

3,210 pairs

MATCH: 412
POSSIBLE: 88
NO_MATCH: 2,710

Pairs

average_score 0.78

Pix received 1,284.90NF 10472MATCH0.98
TED received 9,450.00NF 10466MATCH0.94
Boleto paid 612.35NF 10459POSSIBLE0.71
Bank fee 18.90no pairNO_MATCH

Clients and partners

What Nexus is

Nexus is Openi's reconciliation API. You ingest data from webhooks, files, Postgres or Open Finance, define matching rules and receive each pair of records with a score and a decision: MATCH, POSSIBLE or NO_MATCH.

From raw data to match, with no spreadsheet in between.

Connect the sources
Create data sources of type webhook, file, Postgres, Open Finance or Openi.
Model the fields
Datasets hold the records. Fields extract canonical keys, such as amount and doc, for the rules to use.
Define the rules
A rule set matches two datasets with a JSONata expression and scoring parameters.
Receive the matches
Each result arrives by webhook signed with HMAC-SHA-256, with configurable retries.

Create the source, run the matching, read the result.

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curl -X POST "https://nexus-api.openi.com.br/v1/data-sources" \
  -H "x-api-key: $NEXUS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "type": "webhook",
    "name": "transacoes_banco_x",
    "config": {
      "secret": "a-secret-with-at-least-16-chars",
      "slug": "transacoes-banco-x"
    }
  }'

Request access Full Nexus reference llms.txt

CaseReconciliation at scale

More than 100 million records reconciled

NDD uses Nexus to reconcile more than 100 million records. Data comes in by file, database or webhook, the rule set matches the two sides and each pair comes back with a decision and a score, with no manual queue for what checks out.

records reconciled: 100M+

Read the NDD case

Two datasets, one rule set

Example

origem_a (file)origem_b (database)

Record 000184
R$ 1,284.90
MATCH
Record 77A1
R$ 1,284.90
Record 000185
R$ 312.00
MATCH
Record 77A2
R$ 312.00
Record 000186
R$ 4,790.15
POSSIBLE
Record 77A9
R$ 4,790.51
Record 000187
R$ 96.40
NO_MATCH
no pair

Sample data, to illustrate the flow.

A whole reconciliation platform behind /v1.

Five source types

Real-time JSON events, Postgres tables, CSV, XLSX and Francesinha files, Open Finance transactions and Openi's internal data.

POST /hooks/{slug}
POST /v1/data-sources
CSV, XLSX, .fra up to 1 GB

Compositional matching

1:N, N:1, partial and installment reconciliations, on top of one-to-one.

Scored decisions

Every match carries a score and a decision: MATCH, POSSIBLE or NO_MATCH.

Outbound webhooks

Exponential backoff, a dead letter queue and masking of sensitive fields before delivery.

Usage through the API

Query your tenant's usage and export billing events as CSV.

Simple API: REST, JSON and key authentication. Ready-made examples and a Postman collection in the documentation.
Agent-ready: An MCP server and llms.txt on every product, so your agents can read the documentation and operate the API.
Start free: A free plan on all three products and monthly plans from R$ 59.90, with a usage allowance included.

Combine with the other products

Banking data

Open Finance

Tax invoices

Docs

“We integrated Open Finance in one sprint. The documentation answers before we need to ask.”

Marina DuarteHead of Engineering, credit fintech

“The reconciliation that took the team two days now runs on its own.”

Rafael AntunesCTO, retail chain

Teams from fintechs, retail and accounting already integrate with Openi.

Request access

Run Nexus on your account. The reference is already open.

Read the endpoints, copy the examples above and request credentials to make the same calls with your own data.