### Install Go Dependencies

Source: https://github.com/blnkfinance/blnk/blob/main/CONTRIBUTING.md

Install project dependencies using Go modules. Ensure you have Go installed and configured.

```bash
go mod tidy
```

--------------------------------

### Start Dashboard Server

Source: https://github.com/blnkfinance/blnk/blob/main/tests/loadtest/README.md

Starts the dashboard server to visualize load test results. Use --no-open to prevent automatic browser launch.

```bash
python3 tests/loadtest/tools/dashboard.py
```

```bash
python3 tests/loadtest/tools/dashboard.py --no-open
```

--------------------------------

### Manual Queue Benchmark Start

Source: https://github.com/blnkfinance/blnk/blob/main/tests/loadtest/README.md

Manually starts the queue benchmark tool. Requires Redis DSN and queue prefixes. Use -wait to block until the queue is drained.

```bash
go run ./tests/loadtest/tools/queue_benchmark.go \
  -redis-dsn "$BLNK_REDIS_DNS" \
  -queue-prefixes "new:transaction_,hot_" \
  -wait \
  -out tests/loadtest/queue-summary.json
```

--------------------------------

### Start Local Services with Docker Compose

Source: https://github.com/blnkfinance/blnk/blob/main/CONTRIBUTING.md

Start PostgreSQL and Redis services using Docker Compose. These services are required for local development and testing.

```bash
docker compose up -d postgres redis
```

--------------------------------

### Start Load Test Dashboard

Source: https://github.com/blnkfinance/blnk/blob/main/tests/loadtest/tools/README.md

Starts a local web server for the load test dashboard. It automatically scans for k6 summary files, NDJSON exports, and CSV files.

```bash
python3 tests/loadtest/tools/dashboard.py
```

--------------------------------

### Install act for Local CI

Source: https://github.com/blnkfinance/blnk/blob/main/CONTRIBUTING.md

Install the 'act' tool on macOS using Homebrew. This tool allows running GitHub Actions workflows locally.

```bash
brew install act    # macOS
```

--------------------------------

### Create Blnk Event with Bloc Mapper

Source: https://github.com/blnkfinance/blnk/wiki/Events-&-Mappers

Construct a Blnk event payload using a pre-defined mapper to translate external transaction data. This example shows how to trigger a 'transaction.new' event with Bloc's transaction details.

```json
{
    "mapper_id": "map_3db6f05a-8f5a-43e4-a91c-b5a6c5e7d5a1",
    "drcr": "Credit",
    "balance_id": "bln_c1750613-b4b0-4cde-9793-459165a8715f",
    "data": {
        "event": "transaction.new",
        "data": {
            "amount": 30000,
            "currency": "NGN",
            "reference": "1jhbs3ozmen0k7y5e333feeme3rrr33ewwedffdew",
            "source": "Collection Account",
            "status": "successful"
        }
    }
}
```

--------------------------------

### Run Tests with Make

Source: https://github.com/blnkfinance/blnk/blob/main/CONTRIBUTING.md

Execute tests using the 'make test' command. This is an alternative way to run the test suite.

```bash
make test
```

--------------------------------

### Build Blnk Binary

Source: https://github.com/blnkfinance/blnk/blob/main/CONTRIBUTING.md

Build the Blnk executable binary. This command compiles the Go source files into an executable.

```bash
go build -o blnk ./cmd/*.go
```

--------------------------------

### Run Database Migrations

Source: https://github.com/blnkfinance/blnk/blob/main/CONTRIBUTING.md

Apply database migrations to set up the schema. This command ensures the database is in the correct state for development.

```bash
./blnk migrate up
```

--------------------------------

### Create Balance Monitor Configuration

Source: https://github.com/blnkfinance/blnk/wiki/Ledgers-&-Balances

Configure a balance monitor by specifying the balance ID and the condition to trigger an alert. This is useful for setting up automated monitoring of specific financial thresholds.

```json
{
    "balance_id": "bln_c1750613-b4b0-4cde-9793-459165a8715f",
    "condition": {
        "field": "debit_balance",
        "operator": ">",
        "value": 100000
    }
}
```

--------------------------------

### Clone Blnk Repository

Source: https://github.com/blnkfinance/blnk/blob/main/CONTRIBUTING.md

Clone the Blnk repository to your local machine. This is the first step in setting up the development environment.

```bash
git clone https://github.com/blnkfinance/blnk.git
cd blnk
```

--------------------------------

### Manual k6 Run for Hot Source

Source: https://github.com/blnkfinance/blnk/blob/main/tests/loadtest/README.md

Manually runs a k6 load test scenario targeting a hot source. Configure environment variables for URL, scenario, duration, rate, VUS, and sharding.

```bash
k6 run \
  --out json=tests/loadtest/run.ndjson \
  -e SUMMARY_OUT=tests/loadtest/summary.json \
  -e URL='http://localhost:5001/transactions' \
  -e SCENARIO='hot_source' \
  -e DURATION='30s' \
  -e RATE='300' \
  -e VUS='200' \
  -e MAX_VUS='800' \
  -e SOURCE_BUCKETS='1' \
  tests/loadtest/script.js
```

--------------------------------

### Run Load Test Case

Source: https://github.com/blnkfinance/blnk/blob/main/tests/loadtest/README.md

Executes a predefined load test case using a helper script. This script manages both the queue benchmark and k6 load test execution.

```bash
bash tests/loadtest/run_case.sh hot-to-cold-no-shard
```

```bash
bash tests/loadtest/run_case.sh cold-to-hot-no-shard
```

```bash
bash tests/loadtest/run_case.sh hot-to-cold-shard
```

```bash
bash tests/loadtest/run_case.sh cold-to-hot-shard
```

```bash
bash tests/loadtest/run_case.sh hot-to-cold-no-shard hot
```

--------------------------------

### Generate Queue Benchmark JSON

Source: https://github.com/blnkfinance/blnk/blob/main/tests/loadtest/tools/README.md

Generates a k6-shaped summary JSON from Asynq queue stats for temporary benchmarking. Use -queue-prefix to specify queue names and -wait to pause until backlog appears.

```bash
go run ./tests/loadtest/tools/queue_benchmark.go \
  -queue-prefix new:transaction_ \
  -wait \
  -out tests/loadtest/queue-summary.json
```

```bash
go run ./tests/loadtest/tools/queue_benchmark.go \
  -queues new:transaction_18 \
  -out tests/loadtest/queue-summary.json
```

```bash
go run ./tests/loadtest/tools/queue_benchmark.go \
  -redis-dsn "$BLNK_REDIS_DNS" \
  -queue-prefix new:transaction_ \
  -wait \
  -out tests/loadtest/queue-summary.json
```

--------------------------------

### Manual k6 Run for Hot Destination

Source: https://github.com/blnkfinance/blnk/blob/main/tests/loadtest/README.md

Manually runs a k6 load test scenario targeting a hot destination. Configure environment variables for URL, scenario, duration, rate, VUS, and sharding.

```bash
k6 run \
  --out json=tests/loadtest/run.ndjson \
  -e SUMMARY_OUT=tests/loadtest/summary.json \
  -e URL='http://localhost:5001/transactions' \
  -e SCENARIO='hot_destination' \
  -e DURATION='30s' \
  -e RATE='300' \
  -e VUS='200' \
  -e MAX_VUS='800' \
  -e DESTINATION_BUCKETS='1' \
  tests/loadtest/script.js
```

--------------------------------

### Configure Load Test Dashboard

Source: https://github.com/blnkfinance/blnk/blob/main/tests/loadtest/tools/README.md

Optional flags for the dashboard script. Use --no-open to prevent automatic browser opening, --port to specify a port, and --root to set the scan directory.

```bash
python3 tests/loadtest/tools/dashboard.py --no-open
```

```bash
python3 tests/loadtest/tools/dashboard.py --port 9000
```

```bash
python3 tests/loadtest/tools/dashboard.py --root tests/loadtest
```

--------------------------------

### Manual k6 Run with Increased Sharding

Source: https://github.com/blnkfinance/blnk/blob/main/tests/loadtest/README.md

Reruns a k6 load test with increased sharding for either hot source or hot destination scenarios. Adjust SOURCE_BUCKETS or DESTINATION_BUCKETS accordingly.

```bash
k6 run \
  --out json=tests/loadtest/run.ndjson \
  -e SUMMARY_OUT=tests/loadtest/summary.json \
  -e URL='http://localhost:5001/transactions' \
  -e SCENARIO='hot_source' \
  -e DURATION='30s' \
  -e RATE='300' \
  -e VUS='200' \
  -e MAX_VUS='800' \
  -e SOURCE_BUCKETS='8' \
  tests/loadtest/script.js
```

--------------------------------

### Run Fast Local Tests

Source: https://github.com/blnkfinance/blnk/blob/main/CONTRIBUTING.md

Execute tests locally with the '-short' flag, which skips long-running tests. This is useful for quick feedback during development.

```bash
go test -short ./...
```

--------------------------------

### Run Full Local Tests

Source: https://github.com/blnkfinance/blnk/blob/main/CONTRIBUTING.md

Execute all tests locally without any flags. This provides a comprehensive test coverage check.

```bash
go test ./...
```

--------------------------------

### Run CI Workflow Locally with act

Source: https://github.com/blnkfinance/blnk/blob/main/CONTRIBUTING.md

Execute the GitHub Actions CI pipeline locally using 'act'. Ensure Docker is running before executing this command.

```bash
act -W .github/workflows/go.yml
```

--------------------------------

### Create Blnk Account JSON Structure

Source: https://github.com/blnkfinance/blnk/wiki/Accounts

Use this JSON structure to create a new account in Blnk. Ensure 'identity_id' and 'balance_id' are valid Blnk resource identifiers.

```json
{
    "bank_name": "Blnk bank",
    "number": "30888888832",
    "identity_id": "idt_0501db5c-baf9-4be1-a931-f4bae7f3a41d",
    "balance_id": "bln_c1750613-b4b0-4cde-9793-459165a8715f"
}
```

--------------------------------

### Calculate Rejection Rate by Reason

Source: https://github.com/blnkfinance/blnk/blob/main/docs/metrics.md

Query Prometheus to determine the rate of rejected transactions, broken down by rejection reason, over a 5-minute window.

```promql
# Rejection rate by reason
rate(blnk_transaction_rejected_total[5m])
```

--------------------------------

### Configure Prometheus Scrape Job

Source: https://github.com/blnkfinance/blnk/blob/main/docs/metrics.md

Configure your Prometheus instance to scrape Blnk's metrics endpoint, including bearer token authentication if server security is enabled.

```yaml
scrape_configs:
  - job_name: 'blnk-server'
    authorization:
      type: Bearer
      credentials: '<your-token>'
    static_configs:
      - targets: ['server:5001']
```

--------------------------------

### Calculate Transaction Throughput

Source: https://github.com/blnkfinance/blnk/blob/main/docs/metrics.md

Query Prometheus to calculate the rate of transactions per second over a 5-minute window.

```promql
# Transaction throughput (per second, 5 minute window)
rate(blnk_transaction_total[5m])
```

--------------------------------

### Monitor Queue Enqueue Rate

Source: https://github.com/blnkfinance/blnk/blob/main/docs/metrics.md

This Prometheus query shows the rate at which items are being enqueued into the system's queues over a 5-minute window.

```PromQL
rate(blnk_queue_enqueued_total[5m])
```

--------------------------------

### Create Balance Linked to Identity

Source: https://github.com/blnkfinance/blnk/wiki/Identity

Use this JSON payload to create a new balance and associate it with an existing identity by providing the `identity_id`.

```json
{
    "ledger_id": "ldg_db5eabf0-4152-47cf-8353-d1729a491962",
    "identity_id": "idt_0501db5c-baf9-4be1-a931-f4bae7f3a41d",
    "currency": "NGN"
}
```

--------------------------------

### Create Bloc Transaction Mapper

Source: https://github.com/blnkfinance/blnk/wiki/Events-&-Mappers

Define a JSON structure to map Bloc's transaction data fields to Blnk's standardized format. This mapper specifies how to extract amount, reference, and currency from Bloc's payload.

```json
{
    "name": "Bloc transaction webhook mapping",
    "mapping_instruction": {
        "amount": "{data.amount}",
        "reference": "{data.reference}",
        "currency": "{data.currency}"
    }
}
```

--------------------------------

### Configure External Account Number Generation

Source: https://github.com/blnkfinance/blnk/wiki/Accounts

Include this JSON configuration in your Blnk settings to enable automated account number generation from an external HTTP service.

```json
"account_number_generation": {
    "http_service": {
        "url": "https://example.com/generate_account_number",
        "method": "POST",
        "headers": {
            "Content-Type": "application/json",
            "Authorization": "Bearer some_auth_token"
        }
    }
}
```

--------------------------------

### Calculate P99 Transaction Latency

Source: https://github.com/blnkfinance/blnk/blob/main/docs/metrics.md

Use this Prometheus query to calculate the 99th percentile of transaction durations over a 5-minute window.

```PromQL
histogram_quantile(0.99, rate(blnk_transaction_duration_seconds_bucket[5m]))
```

--------------------------------

### Schedule Transaction Payload

Source: https://github.com/blnkfinance/blnk/wiki/Transactions

Include the 'scheduled_for' parameter with a timestamp in ISO 8601 format to schedule a transaction for future execution. Ensure all other required transaction fields are present.

```json
{
    "amount": 10000,
    "tag": "Commission Earned",
    "reference": "ref",
    "drcr": "Credit",
    "currency": "NGN",
    "ledger_id": "ldg_3fa24854-211f-4248-9611-a7744aeaefcd",
    "balance_id": "bln_0abdbf91-d4b7-4917-bfdc-7fdf1680a3ca",
    "scheduled_for": "2023-10-08T19:48:00Z"
}
```

--------------------------------

### External Account Generation Service Response Format

Source: https://github.com/blnkfinance/blnk/wiki/Accounts

The external service used for account number generation must return JSON in this format, providing the generated account number and its associated bank name.

```json
{
    "account_number": "<generated_account_number>",
    "bank_name": "<associated_bank_name>"
}
```

--------------------------------

### Calculate Hot Lane Traffic Ratio

Source: https://github.com/blnkfinance/blnk/blob/main/docs/metrics.md

This Prometheus query calculates the ratio of traffic routed to the 'hot' lane compared to the total traffic routed. It helps understand the proportion of traffic handled by the specialized hot lane.

```PromQL
blnk_hotpairs_lane_routed_total{lane="hot"} / blnk_hotpairs_lane_routed_total
```

--------------------------------

### Transaction Normalization Function

Source: https://github.com/blnkfinance/blnk/wiki/Fraud-Detection

This pseudo-code function normalizes a given value against a specified minimum and maximum, scaling it to a 0-1 range. It's used to standardize financial parameters for fraud score computation.

```pseudo
function normalize(value, min=0, max) {
    return (value - min) / (max - min)
}
```

--------------------------------

### Blnk Transaction Record

Source: https://github.com/blnkfinance/blnk/wiki/Events-&-Mappers

The resulting Blnk transaction record after processing an event and applying a mapper. This shows the standardized format for a queued transaction, including amounts, currency, and status.

```json
{
  "id": "txn_9da2b9bc-a0f4-4832-bb2a-5a493eedb5b3",
  "tag": "",
  "reference": "1jhbs3ozmen0k7y5e333feeme3rrr33ewwedffdew",
  "amount": 30000,
  "currency": "NGN",
  "drcr": "Credit",
  "status": "QUEUED",
  "ledger_id": "ldg_db5eabf0-4152-47cf-8353-d1729a491962",
  "balance_id": "bln_c1750613-b4b0-4cde-9793-459165a8715f",
  "credit_balance_before": 246000,
  "debit_balance_before": 0,
  "credit_balance_after": 276000,
  "debit_balance_after": 0,
  "balance_before": 246000,
  "balance_after": 276000,
  "created_at": "2023-10-19T07:59:22.052869+01:00",
  "scheduled_for": "0001-01-01T00:00:00Z"
}
```

--------------------------------

### Calculate Worker Retry Rate

Source: https://github.com/blnkfinance/blnk/blob/main/docs/metrics.md

This Prometheus query measures the rate of worker retries over a 5-minute window, indicating the frequency of task failures and subsequent retries.

```PromQL
rate(blnk_worker_retries_total[5m])
```

--------------------------------

### Calculate Batch Coalescing Success Rate

Source: https://github.com/blnkfinance/blnk/blob/main/docs/metrics.md

This Prometheus query determines the success rate of batch coalescing operations by dividing the count of successful batches by the total number of batches processed.

```PromQL
blnk_transaction_batch_total{result="success"} / blnk_transaction_batch_total
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.