Tracer
The real-time control layer: it decides ALLOW / DENY / REVIEW for any transaction in under 100 ms, applying rules and spend limits before the ledger.
POST /v1/decisions
{ "amount": 124000, "account": "customer.account" }
rule daily.limit ok
decision ALLOW
200 ok · before the entry is booked
what it is
Tracer is Lerian's real-time control layer. It makes instant decisions (ALLOW / DENY / REVIEW) for any kind of transaction in under 100 ms, applying spend limits and business rules before the money moves.
A ledger records what happened; Tracer decides beforehand what is allowed to happen. It sits apart from the ledger: it does not read balances, it evaluates the context your system sends. Before recording a transaction in Midaz, your application calls Tracer and submits to the ledger only if the decision is ALLOW.
capabilities
- 01Real-time validation answered in under 80 ms (p99).
- 02Rules engine built on CEL expressions: type-safe, with no code deploy.
- 03Dynamic spend limits per transaction, account, portfolio or segment, with automatic period reset.
- 04Product-agnostic: cards, transfers, Pix and crypto.
- 05Full audit trail with 7+ years of retention (SOX/GLBA).
- 06Configurable default decision (fail-open or fail-closed) when no rule matches.
when to use it
- Spend governance: evaluating transactions against internal or per-customer policies.
- Transaction validation: applying business rules before execution.
- Compliance: producing audit-ready records and guaranteeing traceability.
On the platform.
Sits in front of Midaz: your application validates in Tracer and records the transaction in the ledger only if the decision is ALLOW. Tracer does not connect to Midaz and does not read balances — your application orchestrates the two.
- your applicationasks before the ledger
- Midazonly receives what came back ALLOW
- Flowkertriggers the decision inside the workflow
- Reporterreads the decision trail
Midaz
everything settles here · double entry · immutable trail
Build with Tracer.
Talk to the people who build it — or go straight to the documentation.