tzstats-go – Official Go SDK for the TzStats API

The official Blockwatch Go client library for TzStats. This SDK is free to use under a permissive license and works with the most recent version of the TzStats API v009-2021-04-16. API documentation can be found here.

We will maintain this SDK on a regular basis to keep track of changes to the Tezos network and add new API features as they are released. Open-source support is provided through issues in this Github repository. If you are looking for commercial support, please contact us at licensing@blockwatch.cc.

This SDK is based on TzGo, our open-source Go library for Tezos.

TzStats-Go Versioning

As long as TzStats-Go is in beta status we will use major version 0.x. Once interfaces are stable we switch to 1.x. The minor version number expresses compatibility with a Tezos protocol release, e.g. v0.9.0 supports all protocols up to Florence.

Installation

go get -u blockwatch.cc/tzstats-go

Then import, using

import (
	"blockwatch.cc/tzstats-go"
)

Initializing the TzStats SDK Client

All functions are exported through a Client object. For convenience we have defined two default clients tzstats.DefaultClient for mainnet and tzstats.IpfsClientfor our IPFS gateway. You may construct custom clients for different API URLs like so:

c, err := tzstats.NewClient("https://api.tzstats.com", nil)

The default configuration should work just fine, but if you need special timeouts, proxy or TLS settings you may use a custom http.Client as second argument.

import (
	"crypto/tls"
	"log"
	"net"
	"net/http"

	"blockwatch.cc/tzstats-go"
)


func main() {
	hc := &http.Client{
		Transport: &http.Transport{
			Dial: (&net.Dialer{
				Timeout:   2 * time.Second,
				KeepAlive: 180 * time.Second,
			}).Dial,
			TLSClientConfig: &tls.Config{
				InsecureSkipVerify: true,
			}
		}
	}

	c, err := tzstats.NewClient("https://my-private-index.local:8000", hc)
	if err != nil {
		log.Fatalln(err)
	}
}

Reading a single Tezos Account

import (
  "context"
  "blockwatch.cc/tzstats-go"
  "blockwatch.cc/tzgo/tezos"
)

// use default Mainnet client
client := tzstats.DefaultClient
ctx := context.Background()
addr := tezos.MustParseAddress("tz3RDC3Jdn4j15J7bBHZd29EUee9gVB1CxD9")

// get account data and embed metadata if available
params := tzstats.NewAccountParams().WithMeta()
a, err := client.GetAccount(ctx, addr, params)

Reading Smart Contract Storage

import (
  "context"
  "blockwatch.cc/tzgo"
  "blockwatch.cc/tzstats-go"
)

// use default Mainnet client
client := tzstats.DefaultClient
ctx := context.Background()
addr := tezos.MustParseAddress("KT1Puc9St8wdNoGtLiD2WXaHbWU7styaxYhD")

// read storage from API
params := tzstats.NewContractParams()
raw, err := client.GetContractStorage(ctx, addr, params)

// access individual properties with correct type
tokenAddress, ok := raw.GetAddress("tokenAddress")
tokenPool, ok := raw.GetBig("tokenPool")
xtzPool, ok := raw.GetBig("xtzPool")

Listing Account Transactions

import (
  "context"
  "blockwatch.cc/tzstats-go"
  "blockwatch.cc/tzgo/tezos"
)

// use default Mainnet client
client := tzstats.DefaultClient
ctx := context.Background()
addr := tezos.MustParseAddress("tz1irJKkXS2DBWkU1NnmFQx1c1L7pbGg4yhk")

// list operations sent and received by this account
params := tzstats.NewOpParams().WithLimit(100).WithOrder(tzstats.OrderDesc)
ops, err := client.GetAccountOps(ctx, addr, params)

Cursoring through results

The SDK has a convenient way for fetching results longer than the default maximum of 500 entries by using the unique row_id as offset pointer. An empty result means there is no more data available right now. As the chain grows you can obtain fresh data by using the most recent row_id like shown below

import (
  "context"
  "blockwatch.cc/tzstats-go"
  "blockwatch.cc/tzgo/tezos"
)

client := tzstats.DefaultClient
ctx := context.Background()
addr := tezos.MustParseAddress("tz1irJKkXS2DBWkU1NnmFQx1c1L7pbGg4yhk")
params := tzstats.NewOpParams()

for {
	// fetch next batch from the explorer API
	ops, err := client.GetAccountOps(ctx, addr, params)
	// handle error if necessary

	// stop when result is empty
	if len(ops) == 0 {
		break
	}

	// handle ops here

	// prepare for next iteration
	params = params.WithCursor(ops[len(ops)-1].RowId)
}

Decoding smart contract data into Go types

import (
  "context"
  "blockwatch.cc/tzgo"
  "blockwatch.cc/tzstats-go"
)

// use default Mainnet client
client := tzstats.DefaultClient
ctx := context.Background()
addr := tezos.MustParseAddress("KT1Puc9St8wdNoGtLiD2WXaHbWU7styaxYhD")

// read storage from API
raw, err := client.GetContractStorage(ctx, addr, tzstats.NewContractParams())

// decode into Go struct
type DexterStorage struct {
	Accounts                int64         `json:"accounts"`
	SelfIsUpdatingTokenPool bool          `json:"selfIsUpdatingTokenPool"`
	FreezeBaker             bool          `json:"freezeBaker"`
	LqtTotal                *big.Int      `json:"lqtTotal"`
	Manager                 tezos.Address `json:"manager"`
	TokenAddress            tezos.Address `json:"tokenAddress"`
	TokenPool               *big.Int      `json:"tokenPool"`
	XtzPool                 *big.Int      `json:"xtzPool"`
}

dexterPool := &DexterStorage{}
err := raw.Unmarshal(dexterPool)

Listing bigmap key/value pairs with server-side data unfolding

import (
  "context"
  "blockwatch.cc/tzstats-go"
)

type HicNFT struct {
	TokenId   int               `json:"token_id,string"`
	TokenInfo map[string]string `json:"token_info"`
}

client := tzstats.DefaultClient
ctx := context.Background()
params := tzstats.NewContractParams().
	WithUnpack().
	WithLimit(500)

for {
	// fetch next batch from the explorer API
	nfts, err := client.GetBigmapValues(ctx, 514, params)
	if err != nil {
		return err
	}

	// stop when result is empty
	if len(nfts) == 0 {
		break
	}
	for _, v := range nfts {
		var nft HicNFT
		if err := v.Unmarshal(&nft); err != nil {
			return err
		}
		// handle the value
	}
}

Building complex Table Queries

The TzStats Table API is the fastest way to ingest and process on-chain data in bulk. The SDK defines typed query objects for most tables and allows you to add filter conditions and other configuration to these queries.

import (
  "context"
  "blockwatch.cc/tzstats-go"
)

client := tzstats.DefaultClient
ctx := context.Background()

// create a new query object
q := client.NewBigmapQuery()

// add filters and configure the query to list all active keys
q.WithFilter(tzstats.FilterModeEqual, "bigmap_id", 514).
    WithFilter(tzstats.FilterModeEqual, "action", "update").
    WithFilter(tzstats.FilterModeEqual, "is_deleted", false).
    WithFilter(tzstats.FilterModeEqual, "is_replaced", false).
    WithColumns("row_id", "key_hash", "key", "value").
    WithLimit(1000).
    WithOrder(tzstats.OrderDesc)

// execute the query
list, err := q.Run(ctx)

// walk rows
for _, row := range list.Rows {
	// process data here
}

Listing many Bigmap keys with client-side data unfolding

Extending the example above, we now use TzGo's Micheline features to unfold annotated bigmap data into native Go structs. For efficiency reasons the API only sends binary (hex-encoded) content for smart contract storage. The SDK transparently decodes this into native Micheline primitives for further processing as we see in the example below.

import (
  "context"
  "blockwatch.cc/tzstats-go"
)

type HicNFT struct {
	TokenId   int               `json:"token_id,string"`
	TokenInfo map[string]string `json:"token_info"`
}

client := tzstats.DefaultClient
ctx := context.Background()

// fetch bigmap info with prim (required for key/value types)
params := tzstats.NewContractParams().WithPrim()
info, err := client.GetBigmapType(ctx, 514, params))
keyType := info.MakeKeyType()
valType := info.MakeValueType()

// create a new query object
q := client.NewBigmapQuery()

// add filters and configure the query to list all active keys
q.WithFilter(tzstats.FilterModeEqual, "bigmap_id", 514).
    WithFilter(tzstats.FilterModeEqual, "action", "update").
    WithFilter(tzstats.FilterModeEqual, "is_deleted", false).
    WithFilter(tzstats.FilterModeEqual, "is_replaced", false).
    WithColumns("row_id", "key_hash", "key", "value").
    WithLimit(1000).
    WithOrder(tzstats.OrderDesc)

// execute the query
list, err := q.Run(ctx)

// walk rows
for _, row := range list.Rows {
    // join native value prims with types
    key, val := row.GetKey(keyType), row.GetValue(valType)

    // unpack into Go type
    var nft HicNFT
    err = val.Unmarshal(&nft)

    // or access individual named values
    i, ok := val.GetInt64("token_id")
}

Gracefully handle rate-limits

To avoid excessive overload of our API we limit the rate at which we process your requests. This means your program may from time to time run into a rate limit. To let you gracefully handle retries by waiting until a rate limit resets, we expose the deadline and a done channel much like Go's network context does. Here's how you may use this feature:

var acc *tzstats.Account
for {
	var err error
	acc, err = tzstats.GetAccount(ctx, tezos.MustParseAddress("tz1irJKkXS2DBWkU1NnmFQx1c1L7pbGg4yhk"))
	if err != nil {
		if e, ok := tzstats.IsRateLimited(err); ok {
			fmt.Printf("Rate limited, waiting for %s\n", e.Deadline())
			select {
			case <-ctx.Done():
				// wait until external context is canceled
				err = ctx.Err()
			case <-e.Done():
				// wait until rate limit reset and retry
				continue
			}
		}
	}
	break
}

// handle error and/or result here

License

The MIT License (MIT) Copyright (c) 2021 Blockwatch Data Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.