diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5c09a63..b6c1525 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,27 +8,7 @@ jobs:
   tests:
     runs-on: ubuntu-18.04
     steps:
-    - uses: actions-rs/toolchain@v1
-      with:
-        toolchain: stable
-    - name: Checkout candid repo
-      uses: actions/checkout@v2
-      with:
-        repository: dfinity/candid
-    - name: Install candid tools
-      run: |
-       cd tools/didc
-       cargo install --root /home/runner --path .
-       cd ..
-       cd candiff
-       cargo install --root /home/runner --path .
-       cd ../..
-       echo "::add-path::/home/runner/bin"
     - uses: actions/checkout@v2
-    - name: "didc help (sanity check)"
-      run: didc --help
-    - name: "candiff help (sanity check)"
-      run: candiff --help
     - name: "install dfx"
       run: |
        wget https://sdk.dfinity.org/install.sh
@@ -39,5 +19,13 @@ jobs:
       run: dfx cache install
     - name: "install vessel"
       run: wget --output-document /home/runner/bin/vessel https://github.com/kritzcreek/vessel/releases/download/v0.4.1/vessel-linux64 && chmod +x /home/runner/bin/vessel
+    - name: "install candid tool"
+      run: wget --output-document /home/runner/bin/candiff https://github.com/dfinity/candid/releases/download/2020-08-18/candiff-linux64 && chmod +x /home/runner/bin/candiff
+    - name: "candiff help (sanity check)"
+      run: candiff --help
+    - name: "install didc tool"
+      run: wget --output-document /home/runner/bin/didc https://github.com/dfinity/candid/releases/download/2020-08-18/didc-linux64 && chmod +x /home/runner/bin/didc
+    - name: "didc help (sanity check)"
+      run: didc --help
     - name: "test"
       run: ./test.sh
\ No newline at end of file
diff --git a/test.sh b/test.sh
index 7335575..d408008 100755
--- a/test.sh
+++ b/test.sh
@@ -20,7 +20,30 @@ echo == Test BigMap service.
 echo
 
 dfx canister install BigMapPutGet
+
 LOOP="(true)";
 while [ "$LOOP" == "(true)" ]; do
     LOOP=$(dfx canister call BigMapPutGet doNextCall)
 done
+
+dfx canister call BigMapPutGet getFullLog --output raw > BigMapPutGet.raw
+
+echo BEGIN BigMapPutGet.raw
+cat BigMapPutGet.raw
+echo END BigMapPutGet.raw
+
+echo BEGIN 'didc decode `cat BigMapPutGet.raw` > BigMapPutGet.log'
+didc decode `cat BigMapPutGet.raw` -d .dfx/local/canisters/BigMapPutGet/BigMapPutGet.did -m getFullLog > BigMapPutGet.log 
+echo END 'didc decode `cat BigMapPutGet.raw`'
+
+echo BEGIN "BigMapPutGet.log (latest-captured log)"
+cat BigMapPutGet.log
+echo END "BigMapPutGet.log"
+
+echo BEGIN "test/BigMapPutGet.log (expected log)"
+cat test/BigMapPutGet.log
+echo END "test/BigMapPutGet.log"
+
+echo BEGIN "candiff compares a expected log (left) and latest captured log (right):"
+candiff diff "`cat test/BigMapPutGet.log`" "`cat BigMapPutGet.log`"
+echo END candiff comparison.
diff --git a/test/BigMapPutGet.log b/test/BigMapPutGet.log
new file mode 100644
index 0000000..50b2b8c
--- /dev/null
+++ b/test/BigMapPutGet.log
@@ -0,0 +1 @@
+(vec { record { 0 = variant { put = record { 0 = vec { 0; }; 1 = vec { 0; }; } }; 1 = variant { ok = variant { unit = null } }; }; record { 0 = variant { get = vec { 0; } }; 1 = variant { ok = variant { opt = variant { nat = 0 } } }; }; record { 0 = variant { put = record { 0 = vec { 0; }; 1 = vec { 0; }; } }; 1 = variant { ok = variant { unit = null } }; }; record { 0 = variant { put = record { 0 = vec { 1; }; 1 = vec { 1; }; } }; 1 = variant { ok = variant { unit = null } }; }; record { 0 = variant { get = vec { 0; } }; 1 = variant { ok = variant { opt = variant { nat = 0 } } }; }; record { 0 = variant { get = vec { 1; } }; 1 = variant { ok = variant { opt = variant { nat = 1 } } }; }; })
diff --git a/test/BigMapPutGet.mo b/test/BigMapPutGet.mo
index 594b2db..28c6151 100644
--- a/test/BigMapPutGet.mo
+++ b/test/BigMapPutGet.mo
@@ -2,6 +2,7 @@ import Prim "mo:prim";
 import BigMap "canister:BigMap";
 import Iter "mo:base/Iter";
 import Debug "mo:base/Debug";
+import Buffer "mo:base/Buffer";
 
 import TestBatch "../src/Batch";
 import TestTypes "../src/Types";
@@ -43,7 +44,8 @@ actor {
   };
 
   // some defaults
-  var batch : TestBatch.Batch = newBatches([0, 1, 2, 4, 8
+  var batch : TestBatch.Batch = newBatches([0, 1
+                                            //,2, 4, 8 -- TEMP -- make this faster for CI iteration...
                                             //,128 -- takes an hour or so
                                            ]);
 
@@ -73,12 +75,23 @@ actor {
            Debug.print ("doNextCall - result = " # (debug_show r));
            Debug.print "doNextCall - saving result...";
            batch.saveResult(r);
+           callLog.add((c, r));
            Debug.print "doNextCall end";
            true
          }
     }
   };
 
+  public type CallReq = TestTypes.CallReq;
+  public type CallRes = TestTypes.Res;
+  public type CallLog = [(CallReq, CallRes)];
+
+  var callLog : Buffer.Buffer<(CallReq, CallRes)> = Buffer.Buffer(0);
+
+  public func getFullLog () : async CallLog {
+    callLog.toArray()
+  };
+
   // Bonus:
   // For testing in an open, interactive world:
   // Use this to add other tests not-yet expressed above!