diff --git a/golang/cosmos/app/app.go b/golang/cosmos/app/app.go
index 0ae6faebbbd..763698a1bdc 100644
--- a/golang/cosmos/app/app.go
+++ b/golang/cosmos/app/app.go
@@ -546,7 +546,15 @@ func (app *GaiaApp) InitChainer(ctx sdk.Context, req abci.RequestInitChain) abci
 	if err := tmjson.Unmarshal(req.AppStateBytes, &genesisState); err != nil {
 		panic(err)
 	}
-	return app.mm.InitGenesis(ctx, app.appCodec, genesisState)
+	res := app.mm.InitGenesis(ctx, app.appCodec, genesisState)
+
+	// Set Historical infos in InitChain to ignore genesis params
+	// This is needed for IBC connections not to time out easily
+	stakingParams := app.StakingKeeper.GetParams(ctx)
+	stakingParams.HistoricalEntries = 10000
+	app.StakingKeeper.SetParams(ctx, stakingParams)
+
+	return res
 }
 
 // Commit tells the controller that the block is commited
diff --git a/packages/cosmic-swingset/README-dibc.md b/packages/cosmic-swingset/README-dibc.md
new file mode 100644
index 00000000000..86ac873d040
--- /dev/null
+++ b/packages/cosmic-swingset/README-dibc.md
@@ -0,0 +1,81 @@
+# Using Dynamic IBC (dIBC)
+
+Run `make` in the current (cosmic-swingset) directory to build the Agoric Cosmos
+chain integration.
+
+You will need the Golang Cosmos IBC relayer source code.  You can clone it from
+https://github.com/cosmos/relayer  Don't worry about building it, that will
+happen later.
+
+```sh
+cd relayer
+# Initialize two Agoric chains, and say "y" when prompted to run the `connect` and
+# `run` steps.
+./scripts/nchainz init agoric
+```
+
+Let this run in the background until it says that the connection has been established.
+It will print out something like:
+
+```
+===============================
+=== All connections initialized
+I[2021-02-15|09:53:02.283] ★ Connection created: [ibc0]client{07-tendermint-0}conn{connection-0} -> [ibc1]client{07-tendermint-0}conn{connection-0} 
+===============================
+```
+
+The `ibc0` ag-solo client can be found by running `agoric open --repl`.  If you
+need an `ibc1` client, then you can open it with `agoric open
+--hostport=localhost:8001 --repl`.
+
+## Echo Channel
+
+On the `ibc0` client, send the following request to the REPL to create a channel
+over `connection-0` to the other chain's (`ibc1`) echo server.
+
+```js
+c = home.ibcport[0]~.connect('/ibc-hop/connection-0/ibc-port/echo/ordered/echovsn', { infoMessage(...args) { console.log(...args) } })
+```
+
+The above command will print out instructions in the REPL about how to establish
+the connection.  After following them, and when the relayer has started running,
+you will see the above REPL command resolve to a presence.
+
+Then:
+```js
+c~.send(`Hello, world!`)
+```
+
+Watch the relayer that you started by following the "connect" instructions
+above.  You'll see it forwards a single packet and acknowledgement.  There may
+be errors, but that's par for the course with the current relayer.  All that
+matters is that after the acknowledgement is relayed, you'll see the above REPL
+command resolve to:
+
+```js
+"Hello, world!"
+```
+
+## Fungible Token Transfer Channel
+
+To test interoperability between the IBC transfer application and dIBC, run the
+following in the `ibc0` REPL:
+
+```js
+c = home.ibcport[0]~.connect('/ibc-hop/connection-0/ibc-port/transfer/unordered/ics20-1', { infoMessage(...args) { console.log(...args) }, onReceive(c, p) { console.log('received', p) }, onOpen(c) { console.log('opened') } })
+```
+
+Again, follow the instructions printed to the REPL.
+
+Then run the IBC transfer request, where `path-2` is the path that was printed
+in the newly-started relayer:
+
+```sh
+rly tx xfer ibc1 ibc0 10000n0token $(rly keys show ibc0 testkey) -ppath-2
+```
+
+You should see an inbound message in your REPL like:
+
+```js
+{ "type": "ibc/transfer/PacketDataTransfer", "value": transfer_message }
+```
diff --git a/packages/cosmic-swingset/bin/ag-nchainz b/packages/cosmic-swingset/bin/ag-nchainz
index 5229ef36ab6..b9586f1b44b 100755
--- a/packages/cosmic-swingset/bin/ag-nchainz
+++ b/packages/cosmic-swingset/bin/ag-nchainz
@@ -19,6 +19,7 @@ NUM_SOLOS=1
 real0=$(readlink "${BASH_SOURCE[0]}" || echo "${BASH_SOURCE[0]}")
 thisdir=$(cd "$(dirname -- "$real0")" && pwd -P)
 
+PATHCONFIG=nchainz/config/paths
 CLI=ag-cosmos-helper
 DAEMON=ag-chain-cosmos
 SOLO=$thisdir/ag-solo
@@ -170,12 +171,12 @@ start-relayer)
   # Extract existing config.
   for path in $(jq '.paths | keys | .[]' "$cfgfile"); do
     rawpath=$(echo "$path" | jq -r .)
-    jq -r ".paths[$path]" "$cfgfile" > "nchainz/config/$rawpath.json"
+    jq -r ".paths[$path]" "$cfgfile" > "$PATHCONFIG/$rawpath.json"
   done
 
   jqexpr=
-  for fname in nchainz/config/*.json; do
-    [[ -z $template || $fname == "nchainz/config/$template.json" ]] || continue
+  for fname in $PATHCONFIG/*.json; do
+    [[ -z $template || $fname == "$PATHCONFIG/$template.json" ]] || continue
     [[ $fname =~ $BASE_RE ]] || continue
     if grep -q '"generator": "ag-nchainz"' "$fname"; then :
     else
@@ -200,9 +201,9 @@ start-relayer)
 
   if [[ -z $jqexpr ]]; then
     if [[ -n $template ]]; then
-      echo 1>&2 "Connection ID \`$srccid' is not defined in nchainz/config/$template.json"
+      echo 1>&2 "Connection ID \`$srccid' is not defined in $PATHCONFIG/$template.json"
     else
-      echo 1>&2 "Connection ID \`$srccid' is not defined in nchainz/config/*.json"
+      echo 1>&2 "Connection ID \`$srccid' is not defined in $PATHCONFIG/*.json"
     fi
     exit 1
   fi
@@ -215,24 +216,30 @@ start-relayer)
     echo "Replacing path \`$path'"
     path=$template
     jq -s "$jqexpr" \
-      "nchainz/config/$template.json" "$tmpfile" > "nchainz/config/$path.json"
+      "$PATHCONFIG/$template.json" "$tmpfile" > "$PATHCONFIG/$path.json"
   else
     # Create a new path.
     i=0
     path=path-$i
-    while [[ -e "nchainz/config/$path.json" ]]; do
+    while [[ -e "$PATHCONFIG/$path.json" ]]; do
       i=$(( $i + 1 ))
       path=path-$i
     done
 
     echo "Creating new path \`$path'"
     jq -s "$jqexpr"' * { "generator": "ag-nchainz" }' \
-      "nchainz/config/$template.json" "$tmpfile" > "nchainz/config/$path.json"
+      "$PATHCONFIG/$template.json" "$tmpfile" > "$PATHCONFIG/$path.json"
   fi
 
-  echo "$ rly config add-dir nchainz/config/"
-  rly config add-dir nchainz/config/
+  # Bottom-up relay path validation may fail if src or dst chain is not past
+  # block #2.
+  # Keep trying to add-paths until both the chains have booted up.
+  echo "$ rly config add-paths $PATHCONFIG/"
+  while ! rly config add-paths $PATHCONFIG/; do
+    sleep 3
+  done
 
+  echo "$ rly link $path --timeout=3s -d"
   try=0
   while ! rly tx link $path --timeout=3s -d >> "nchainz/logs/$path.log" 2>&1; do
     try=$(( $try + 1 ))