diff --git a/pkg/config/toml_config/chain_test.go b/pkg/config/toml_config/chain_test.go
new file mode 100644
index 0000000..e09c3a5
--- /dev/null
+++ b/pkg/config/toml_config/chain_test.go
@@ -0,0 +1,319 @@
+package toml_config_test
+
+import (
+	tomlConfig "main/pkg/config/toml_config"
+	"main/pkg/config/types"
+	"testing"
+
+	queryPkg "github.com/cometbft/cometbft/libs/pubsub/query"
+	"github.com/stretchr/testify/require"
+)
+
+func TestChainEmptyName(t *testing.T) {
+	t.Parallel()
+
+	chain := tomlConfig.Chain{}
+	require.Error(t, chain.Validate())
+}
+
+func TestChainEmptyTendermintNodes(t *testing.T) {
+	t.Parallel()
+
+	chain := tomlConfig.Chain{
+		Name: "chain",
+	}
+	require.Error(t, chain.Validate())
+}
+
+func TestChainEmptyApiNodes(t *testing.T) {
+	t.Parallel()
+
+	chain := tomlConfig.Chain{
+		Name:            "chain",
+		TendermintNodes: []string{"node"},
+	}
+	require.Error(t, chain.Validate())
+}
+
+func TestChainEmptyQueries(t *testing.T) {
+	t.Parallel()
+
+	chain := tomlConfig.Chain{
+		Name:            "chain",
+		TendermintNodes: []string{"node"},
+		APINodes:        []string{"node"},
+	}
+	require.Error(t, chain.Validate())
+}
+
+func TestChainInvalidQuery(t *testing.T) {
+	t.Parallel()
+
+	chain := tomlConfig.Chain{
+		Name:            "chain",
+		TendermintNodes: []string{"node"},
+		APINodes:        []string{"node"},
+		Queries:         []string{"query"},
+	}
+	require.Error(t, chain.Validate())
+}
+
+func TestChainInvalidDenom(t *testing.T) {
+	t.Parallel()
+
+	chain := tomlConfig.Chain{
+		Name:            "chain",
+		TendermintNodes: []string{"node"},
+		APINodes:        []string{"node"},
+		Queries:         []string{"event.key = 'value'"},
+		Denoms: tomlConfig.DenomInfos{
+			{},
+		},
+	}
+	require.Error(t, chain.Validate())
+}
+
+func TestChainValid(t *testing.T) {
+	t.Parallel()
+
+	chain := tomlConfig.Chain{
+		Name:            "chain",
+		TendermintNodes: []string{"node"},
+		APINodes:        []string{"node"},
+		Queries:         []string{"event.key = 'value'"},
+	}
+	require.NoError(t, chain.Validate())
+}
+
+func TestChainToAppConfigChainBasic(t *testing.T) {
+	t.Parallel()
+
+	chain := tomlConfig.Chain{
+		Name:            "chain",
+		PrettyName:      "Chain",
+		ChainID:         "chain-id",
+		TendermintNodes: []string{"tendermint-node"},
+		APINodes:        []string{"api-node"},
+		Queries:         []string{"event.key = 'value'"},
+	}
+	appConfigChain := chain.ToAppConfigChain()
+
+	require.Equal(t, "chain", appConfigChain.Name)
+	require.Equal(t, "Chain", appConfigChain.PrettyName)
+	require.Equal(t, "chain-id", appConfigChain.ChainID)
+	require.Len(t, appConfigChain.TendermintNodes, 1)
+	require.Equal(t, "tendermint-node", appConfigChain.TendermintNodes[0])
+	require.Len(t, appConfigChain.APINodes, 1)
+	require.Equal(t, "api-node", appConfigChain.APINodes[0])
+	require.Len(t, appConfigChain.Queries, 1)
+	require.Equal(t, "event.key = 'value'", appConfigChain.Queries[0].String())
+}
+
+func TestChainToAppConfigChainMintscan(t *testing.T) {
+	t.Parallel()
+
+	chain := tomlConfig.Chain{
+		Name:            "chain",
+		PrettyName:      "Chain",
+		ChainID:         "chain-id",
+		TendermintNodes: []string{"tendermint-node"},
+		APINodes:        []string{"api-node"},
+		Queries:         []string{"event.key = 'value'"},
+		MintscanPrefix:  "chain",
+	}
+	appConfigChain := chain.ToAppConfigChain()
+
+	require.NotNil(t, appConfigChain.Explorer)
+	require.Equal(t, "https://mintscan.io/chain/validators/%s", appConfigChain.Explorer.ValidatorLinkPattern)
+}
+
+func TestChainToAppConfigChainPing(t *testing.T) {
+	t.Parallel()
+
+	chain := tomlConfig.Chain{
+		Name:            "chain",
+		PrettyName:      "Chain",
+		ChainID:         "chain-id",
+		TendermintNodes: []string{"tendermint-node"},
+		APINodes:        []string{"api-node"},
+		Queries:         []string{"event.key = 'value'"},
+		PingPrefix:      "chain",
+		PingBaseUrl:     "https://example.com",
+	}
+	appConfigChain := chain.ToAppConfigChain()
+
+	require.NotNil(t, appConfigChain.Explorer)
+	require.Equal(t, "https://example.com/chain/staking/%s", appConfigChain.Explorer.ValidatorLinkPattern)
+}
+
+func TestChainToAppConfigChainCustomExplorer(t *testing.T) {
+	t.Parallel()
+
+	chain := tomlConfig.Chain{
+		Name:            "chain",
+		PrettyName:      "Chain",
+		ChainID:         "chain-id",
+		TendermintNodes: []string{"tendermint-node"},
+		APINodes:        []string{"api-node"},
+		Queries:         []string{"event.key = 'value'"},
+		Explorer: &tomlConfig.Explorer{
+			ValidatorLinkPattern: "test/%s",
+		},
+	}
+	appConfigChain := chain.ToAppConfigChain()
+
+	require.NotNil(t, appConfigChain.Explorer)
+	require.Equal(t, "test/%s", appConfigChain.Explorer.ValidatorLinkPattern)
+}
+
+func TestChainToTomlConfigChainBasic(t *testing.T) {
+	t.Parallel()
+
+	query := queryPkg.MustParse("event.key = 'value'")
+
+	chain := &types.Chain{
+		Name:            "chain",
+		PrettyName:      "Chain",
+		ChainID:         "chain-id",
+		TendermintNodes: []string{"tendermint-node"},
+		APINodes:        []string{"api-node"},
+		Queries:         []queryPkg.Query{*query},
+	}
+
+	tomlConfigChain := tomlConfig.FromAppConfigChain(chain)
+
+	require.Equal(t, "chain", tomlConfigChain.Name)
+	require.Equal(t, "Chain", tomlConfigChain.PrettyName)
+	require.Equal(t, "chain-id", tomlConfigChain.ChainID)
+	require.Len(t, tomlConfigChain.TendermintNodes, 1)
+	require.Equal(t, "tendermint-node", tomlConfigChain.TendermintNodes[0])
+	require.Len(t, tomlConfigChain.APINodes, 1)
+	require.Equal(t, "api-node", tomlConfigChain.APINodes[0])
+	require.Len(t, tomlConfigChain.Queries, 1)
+	require.Equal(t, "event.key = 'value'", tomlConfigChain.Queries[0])
+}
+
+func TestChainToTomlConfigChainMintscan(t *testing.T) {
+	t.Parallel()
+
+	query := queryPkg.MustParse("event.key = 'value'")
+
+	chain := &types.Chain{
+		Name:              "chain",
+		PrettyName:        "Chain",
+		ChainID:           "chain-id",
+		TendermintNodes:   []string{"tendermint-node"},
+		APINodes:          []string{"api-node"},
+		Queries:           []queryPkg.Query{*query},
+		SupportedExplorer: &types.MintscanExplorer{Prefix: "chain"},
+	}
+	tomlConfigChain := tomlConfig.FromAppConfigChain(chain)
+
+	require.Equal(t, "chain", tomlConfigChain.MintscanPrefix)
+}
+
+func TestChainToTomlConfigChainPing(t *testing.T) {
+	t.Parallel()
+
+	query := queryPkg.MustParse("event.key = 'value'")
+
+	chain := &types.Chain{
+		Name:              "chain",
+		PrettyName:        "Chain",
+		ChainID:           "chain-id",
+		TendermintNodes:   []string{"tendermint-node"},
+		APINodes:          []string{"api-node"},
+		Queries:           []queryPkg.Query{*query},
+		SupportedExplorer: &types.PingExplorer{Prefix: "chain", BaseUrl: "https://example.com"},
+	}
+	tomlConfigChain := tomlConfig.FromAppConfigChain(chain)
+
+	require.Equal(t, "chain", tomlConfigChain.PingPrefix)
+	require.Equal(t, "https://example.com", tomlConfigChain.PingBaseUrl)
+}
+
+func TestChainToTomlConfigChainCustomExplorer(t *testing.T) {
+	t.Parallel()
+
+	query := queryPkg.MustParse("event.key = 'value'")
+
+	chain := &types.Chain{
+		Name:            "chain",
+		PrettyName:      "Chain",
+		ChainID:         "chain-id",
+		TendermintNodes: []string{"tendermint-node"},
+		APINodes:        []string{"api-node"},
+		Queries:         []queryPkg.Query{*query},
+		Explorer: &types.Explorer{
+			ValidatorLinkPattern: "test/%s",
+		},
+	}
+	tomlConfigChain := tomlConfig.FromAppConfigChain(chain)
+
+	require.NotNil(t, tomlConfigChain.Explorer)
+	require.Equal(t, "test/%s", tomlConfigChain.Explorer.ValidatorLinkPattern)
+}
+
+func TestChainsInvalid(t *testing.T) {
+	t.Parallel()
+
+	chain := &tomlConfig.Chain{}
+	chains := tomlConfig.Chains{chain}
+
+	require.Error(t, chains.Validate())
+}
+
+func TestChainsDuplicateName(t *testing.T) {
+	t.Parallel()
+
+	chain1 := &tomlConfig.Chain{
+		Name:            "chain",
+		TendermintNodes: []string{"node"},
+		APINodes:        []string{"node"},
+		Queries:         []string{"event.key = 'value'"},
+	}
+	chain2 := &tomlConfig.Chain{
+		Name:            "chain",
+		TendermintNodes: []string{"node"},
+		APINodes:        []string{"node"},
+		Queries:         []string{"event.key = 'value'"},
+	}
+	chains := tomlConfig.Chains{chain1, chain2}
+
+	require.Error(t, chains.Validate())
+}
+
+func TestChainsValid(t *testing.T) {
+	t.Parallel()
+
+	chain1 := &tomlConfig.Chain{
+		Name:            "chain1",
+		TendermintNodes: []string{"node"},
+		APINodes:        []string{"node"},
+		Queries:         []string{"event.key = 'value'"},
+	}
+	chain2 := &tomlConfig.Chain{
+		Name:            "chain2",
+		TendermintNodes: []string{"node"},
+		APINodes:        []string{"node"},
+		Queries:         []string{"event.key = 'value'"},
+	}
+	chains := tomlConfig.Chains{chain1, chain2}
+
+	require.NoError(t, chains.Validate())
+}
+
+func TestHasChainByName(t *testing.T) {
+	t.Parallel()
+
+	chain := &tomlConfig.Chain{
+		Name:            "chain-1",
+		TendermintNodes: []string{"node"},
+		APINodes:        []string{"node"},
+		Queries:         []string{"event.key = 'value'"},
+	}
+	chains := tomlConfig.Chains{chain}
+
+	require.True(t, chains.HasChainByName("chain-1"))
+	require.False(t, chains.HasChainByName("chain-2"))
+}