diff --git a/btc/summary.go b/btc/summary.go
new file mode 100644
index 0000000..9a79bc4
--- /dev/null
+++ b/btc/summary.go
@@ -0,0 +1,154 @@
+package btc
+
+import (
+	"github.com/btcsuite/btclog"
+	"github.com/guggero/chantools/dataformat"
+)
+
+func SummarizeChannels(apiURL string, channels []*dataformat.SummaryEntry,
+	log btclog.Logger) (*dataformat.SummaryEntryFile, error) {
+
+	summaryFile := &dataformat.SummaryEntryFile{
+		Channels: channels,
+	}
+	api := &ExplorerAPI{BaseURL: apiURL}
+
+	for idx, channel := range channels {
+		tx, err := api.Transaction(channel.FundingTXID)
+		if err == ErrTxNotFound {
+			log.Errorf("Funding TX %s not found. Ignoring.",
+				channel.FundingTXID)
+			channel.ChanExists = false
+			continue
+		}
+		if err != nil {
+			log.Errorf("Problem with channel %d (%s): %v.",
+				idx, channel.FundingTXID, err)
+			return nil, err
+		}
+		channel.ChanExists = true
+		outspend := tx.Vout[channel.FundingTXIndex].Outspend
+		if outspend.Spent {
+			summaryFile.ClosedChannels++
+			channel.ClosingTX = &dataformat.ClosingTX{
+				TXID:       outspend.Txid,
+				ConfHeight: uint32(outspend.Status.BlockHeight),
+			}
+
+			err := reportOutspend(
+				api, summaryFile, channel, outspend, log,
+			)
+			if err != nil {
+				log.Errorf("Problem with channel %d (%s): %v.",
+					idx, channel.FundingTXID, err)
+				return nil, err
+			}
+		} else {
+			summaryFile.OpenChannels++
+			summaryFile.FundsOpenChannels += channel.LocalBalance
+			channel.ClosingTX = nil
+			channel.HasPotential = true
+		}
+
+		if idx%50 == 0 {
+			log.Infof("Queried channel %d of %d.", idx,
+				len(channels))
+		}
+	}
+
+	return summaryFile, nil
+}
+
+func reportOutspend(api *ExplorerAPI,
+	summaryFile *dataformat.SummaryEntryFile,
+	entry *dataformat.SummaryEntry, os *Outspend, log btclog.Logger) error {
+
+	spendTx, err := api.Transaction(os.Txid)
+	if err != nil {
+		return err
+	}
+
+	summaryFile.FundsClosedChannels += entry.LocalBalance
+	var utxo []*Vout
+	for _, vout := range spendTx.Vout {
+		if !vout.Outspend.Spent {
+			utxo = append(utxo, vout)
+		}
+	}
+
+	if isCoopClose(spendTx) {
+		summaryFile.CoopClosedChannels++
+		summaryFile.FundsCoopClose += entry.LocalBalance
+		entry.ClosingTX.ForceClose = false
+		entry.ClosingTX.AllOutsSpent = len(utxo) == 0
+		entry.HasPotential = entry.LocalBalance > 0 && len(utxo) != 0
+		return nil
+	}
+
+	summaryFile.ForceClosedChannels++
+	entry.ClosingTX.ForceClose = true
+	entry.HasPotential = false
+
+	if len(utxo) > 0 {
+		log.Debugf("Channel %s spent by %s:%d which has %d outputs of "+
+			"which %d are unspent.", entry.ChannelPoint, os.Txid,
+			os.Vin, len(spendTx.Vout), len(utxo))
+
+		entry.ClosingTX.AllOutsSpent = false
+		summaryFile.ChannelsWithUnspent++
+
+		if couldBeOurs(entry, utxo) {
+			summaryFile.ChannelsWithPotential++
+			summaryFile.FundsForceClose += utxo[0].Value
+			entry.HasPotential = true
+
+			// Could maybe be brute forced.
+			if len(utxo) == 1 &&
+				utxo[0].ScriptPubkeyType == "v0_p2wpkh" &&
+				!utxo[0].Outspend.Spent {
+
+				entry.ClosingTX.OurAddr = utxo[0].ScriptPubkeyAddr
+			}
+		} else {
+			// It's theirs, ignore.
+			if entry.LocalBalance == 0 ||
+				(len(utxo) == 1 &&
+					utxo[0].Value == entry.RemoteBalance) {
+
+				return nil
+			}
+
+			// We don't know what this output is, logging for debug.
+			for idx, vout := range spendTx.Vout {
+				if !vout.Outspend.Spent {
+					log.Debugf("UTXO %d of type %s with "+
+						"value %d", idx,
+						vout.ScriptPubkeyType,
+						vout.Value)
+				}
+			}
+			log.Debugf("Local balance: %d", entry.LocalBalance)
+			log.Debugf("Remote balance: %d", entry.RemoteBalance)
+			log.Debugf("Initiator: %v", entry.Initiator)
+		}
+	} else {
+		entry.ClosingTX.AllOutsSpent = true
+		entry.HasPotential = false
+		summaryFile.FundsClosedSpent += entry.LocalBalance
+		summaryFile.FullySpentChannels++
+	}
+
+	return nil
+}
+
+func couldBeOurs(entry *dataformat.SummaryEntry, utxo []*Vout) bool {
+	if len(utxo) == 1 && utxo[0].Value == entry.RemoteBalance {
+		return false
+	}
+
+	return entry.LocalBalance != 0
+}
+
+func isCoopClose(tx *TX) bool {
+	return tx.Vin[0].Sequence == 0xffffffff
+}
diff --git a/cmd/chantools/summary.go b/cmd/chantools/summary.go
index 2adf0ee..e9da76e 100644
--- a/cmd/chantools/summary.go
+++ b/cmd/chantools/summary.go
@@ -26,52 +26,9 @@ func (c *summaryCommand) Execute(_ []string) error {
 func summarizeChannels(apiURL string,
 	channels []*dataformat.SummaryEntry) error {
 
-	summaryFile := &dataformat.SummaryEntryFile{
-		Channels: channels,
-	}
-	api := &btc.ExplorerAPI{BaseURL: apiURL}
-
-	for idx, channel := range channels {
-		tx, err := api.Transaction(channel.FundingTXID)
-		if err == btc.ErrTxNotFound {
-			log.Errorf("Funding TX %s not found. Ignoring.",
-				channel.FundingTXID)
-			channel.ChanExists = false
-			continue
-		}
-		if err != nil {
-			log.Errorf("Problem with channel %d (%s): %v.",
-				idx, channel.FundingTXID, err)
-			return err
-		}
-		channel.ChanExists = true
-		outspend := tx.Vout[channel.FundingTXIndex].Outspend
-		if outspend.Spent {
-			summaryFile.ClosedChannels++
-			channel.ClosingTX = &dataformat.ClosingTX{
-				TXID:       outspend.Txid,
-				ConfHeight: uint32(outspend.Status.BlockHeight),
-			}
-
-			err := reportOutspend(
-				api, summaryFile, channel, outspend,
-			)
-			if err != nil {
-				log.Errorf("Problem with channel %d (%s): %v.",
-					idx, channel.FundingTXID, err)
-				return err
-			}
-		} else {
-			summaryFile.OpenChannels++
-			summaryFile.FundsOpenChannels += channel.LocalBalance
-			channel.ClosingTX = nil
-			channel.HasPotential = true
-		}
-
-		if idx%50 == 0 {
-			log.Infof("Queried channel %d of %d.", idx,
-				len(channels))
-		}
+	summaryFile, err := btc.SummarizeChannels(apiURL, channels, log)
+	if err != nil {
+		return fmt.Errorf("error running summary: %v", err)
 	}
 
 	log.Info("Finished scanning.")
@@ -105,97 +62,3 @@ func summarizeChannels(apiURL string,
 	log.Infof("Writing result to %s", fileName)
 	return ioutil.WriteFile(fileName, summaryBytes, 0644)
 }
-
-func reportOutspend(api *btc.ExplorerAPI,
-	summaryFile *dataformat.SummaryEntryFile,
-	entry *dataformat.SummaryEntry, os *btc.Outspend) error {
-
-	spendTx, err := api.Transaction(os.Txid)
-	if err != nil {
-		return err
-	}
-
-	summaryFile.FundsClosedChannels += entry.LocalBalance
-	var utxo []*btc.Vout
-	for _, vout := range spendTx.Vout {
-		if !vout.Outspend.Spent {
-			utxo = append(utxo, vout)
-		}
-	}
-
-	if isCoopClose(spendTx) {
-		summaryFile.CoopClosedChannels++
-		summaryFile.FundsCoopClose += entry.LocalBalance
-		entry.ClosingTX.ForceClose = false
-		entry.ClosingTX.AllOutsSpent = len(utxo) == 0
-		entry.HasPotential = entry.LocalBalance > 0 && len(utxo) != 0
-		return nil
-	}
-
-	summaryFile.ForceClosedChannels++
-	entry.ClosingTX.ForceClose = true
-	entry.HasPotential = false
-
-	if len(utxo) > 0 {
-		log.Debugf("Channel %s spent by %s:%d which has %d outputs of "+
-			"which %d are unspent.", entry.ChannelPoint, os.Txid,
-			os.Vin, len(spendTx.Vout), len(utxo))
-
-		entry.ClosingTX.AllOutsSpent = false
-		summaryFile.ChannelsWithUnspent++
-
-		if couldBeOurs(entry, utxo) {
-			summaryFile.ChannelsWithPotential++
-			summaryFile.FundsForceClose += utxo[0].Value
-			entry.HasPotential = true
-
-			// Could maybe be brute forced.
-			if len(utxo) == 1 &&
-				utxo[0].ScriptPubkeyType == "v0_p2wpkh" &&
-				!utxo[0].Outspend.Spent {
-
-				entry.ClosingTX.OurAddr = utxo[0].ScriptPubkeyAddr
-			}
-		} else {
-			// It's theirs, ignore.
-			if entry.LocalBalance == 0 ||
-				(len(utxo) == 1 &&
-					utxo[0].Value == entry.RemoteBalance) {
-
-				return nil
-			}
-
-			// We don't know what this output is, logging for debug.
-			for idx, vout := range spendTx.Vout {
-				if !vout.Outspend.Spent {
-					log.Debugf("UTXO %d of type %s with "+
-						"value %d", idx,
-						vout.ScriptPubkeyType,
-						vout.Value)
-				}
-			}
-			log.Debugf("Local balance: %d", entry.LocalBalance)
-			log.Debugf("Remote balance: %d", entry.RemoteBalance)
-			log.Debugf("Initiator: %v", entry.Initiator)
-		}
-	} else {
-		entry.ClosingTX.AllOutsSpent = true
-		entry.HasPotential = false
-		summaryFile.FundsClosedSpent += entry.LocalBalance
-		summaryFile.FullySpentChannels++
-	}
-
-	return nil
-}
-
-func couldBeOurs(entry *dataformat.SummaryEntry, utxo []*btc.Vout) bool {
-	if len(utxo) == 1 && utxo[0].Value == entry.RemoteBalance {
-		return false
-	}
-
-	return entry.LocalBalance != 0
-}
-
-func isCoopClose(tx *btc.TX) bool {
-	return tx.Vin[0].Sequence == 0xffffffff
-}