Sentinel

Sentinel is a custom built reverse proxy (similar to nginx). Its role is be the front facing services that proxies requests to backend services (ie an RPC). It is also in charge of authentication/authorization as well as rate limiting services.

🚀 Starting the Sentinel Service

🛠️ Build the Sentinel Binary

Compile the Sentinel binary by running:

make install

⚙️ Set Environment Variables

Configure the environment variables as follows:

MONIKER="<your-moniker>" \
WEBSITE="<website-address>" \
DESCRIPTION="<provider description>" \
LOCATION="<location>" \
PORT="<sentinel-port>" \
SOURCE_CHAIN="<arkeo chain address>" \
EVENT_STREAM_HOST="<arkeo event stream host (rpc address)>" \
FREE_RATE_LIMIT=<free tier rate limit> \
FREE_RATE_LIMIT_DURATION="<duration>" \
CLAIM_STORE_LOCATION="~/.arkeo/claims" \
CONTRACT_CONFIG_STORE_LOCATION="~/.arkeo/contract_configs" \
PROVIDER_PUBKEY="<Provider PubKey>" \
PROVIDER_CONFIG_STORE_LOCATION="~/.arkeo/provider"

▶️ Run Sentinel

Start the Sentinel service by executing:

sentinel

API Documentation

Metadata

To retrieve the metadata of any given data provider query the following endpoint

$ curl -s http://<ip-address>:3636/metadata.json | jq
{
  "config": {
    "moniker": "n/a",
    "website": "n/a",
    "description": "n/a",
    "location": "n/a",
    "port": "3636",
    "source_chain": "http://arkeo:1317",
    "event_stream_host": "arkeo:26657",
    "claim_store_location": "${HOME}/.arkeo/claims",
    "provider_pubkey": "arkeopub1-----------------",
    "free_tier_rate_limit": 10
  },
  "version": "0.1.0"
}

Active Contracts

This endpoint returns a list of active contracts for this specific data provider

$ curl -s http://<ip-address>:3636/active-contract/<service>/<spender_pubkey> | jq

Claims

This endpoint returns the latest claim for a given contract Id.

$ curl -s http://<ip-address>:3636/claim/<contract_id> | jq

The open claims endpoint is used to get a list of claims to contracts that haven't been claimed yet. Anything showing up in this endpoint is available to be claimed on chain.

$ curl -s http://<ip-address>:3636/open-claims | jq

Authentication

To make an authenticated request, one must first have an open contract with a given data provider. Once you have an open contract with a contract Id, add query arg do your request as such

/?arkauth=<contract_id>:<nonce>:<signature>

If the contract is an open contract, no need to supply the nonce or the signature (as anyone is allow to query this paid contract)

The nonce refers to counter that increments on each request to the data provider. If the client doesn't know the current nonce, query the claim (/claim/<contract_id>) which will include both the nonce and the signature to prove its correct.

If your contract is an "open" authorization, you can just supply the contract_id (no need to nonce or signature).

To create the signature, use your private key to sign the following text

<contract_id>:<nonce>

The signature produce should be hex encoded into a string for transmission (sample). There is a command line tool to creating this signature in the arkeo codebase, called signhere