diff --git a/apis/eventstream/index.yaml b/apis/eventstream/index.yaml
index 68b6cf86..d9f7ba45 100644
--- a/apis/eventstream/index.yaml
+++ b/apis/eventstream/index.yaml
@@ -25,6 +25,7 @@ get:
             - voluntary_exit
             - finalized_checkpoint
             - chain_reorg
+            - contribution_and_proof
   responses:
     "200":
       description: Opened SSE stream.
@@ -37,39 +38,38 @@ get:
             head:
               description: The node has finished processing, resulting in a new head. previous_duty_dependent_root is `get_block_root_at_slot(state, compute_start_slot_at_epoch(epoch - 1) - 1)` and current_duty_dependent_root is `get_block_root_at_slot(state, compute_start_slot_at_epoch(epoch) - 1)`. Both dependent roots use the genesis block root in the case of underflow.
               value: |
-                event: head\n
-                data: "{\"slot\": \"10\", \"block\": \"0x9a2fefd2fdb57f74993c7780ea5b9030d2897b615b89f808011ca5aebed54eaf\", \"state\":\"0x600e852a08c1200654ddf11025f1ceacb3c2e74bdd5c630cde0838b2591b69f9\", \"epoch_transition\": false, \"previous_duty_dependent_root\": \"0x5e0043f107cb57913498fbf2f99ff55e730bf1e151f02f221e977c91a90a0e91\", \"current_duty_dependent_root\": \"0x5e0043f107cb57913498fbf2f99ff55e730bf1e151f02f221e977c91a90a0e91\"}"\n
-                \n
+                event: head
+                data: {"slot":"10", "block":"0x9a2fefd2fdb57f74993c7780ea5b9030d2897b615b89f808011ca5aebed54eaf", "state":"0x600e852a08c1200654ddf11025f1ceacb3c2e74bdd5c630cde0838b2591b69f9", "epoch_transition":false, "previous_duty_dependent_root":"0x5e0043f107cb57913498fbf2f99ff55e730bf1e151f02f221e977c91a90a0e91", "current_duty_dependent_root":"0x5e0043f107cb57913498fbf2f99ff55e730bf1e151f02f221e977c91a90a0e91"}
             block:
               description: The node has received a valid block (from P2P or API)
               value: |
-                event: block\n
-                data: "{\"slot\": \"10\", \"block\": \"0x9a2fefd2fdb57f74993c7780ea5b9030d2897b615b89f808011ca5aebed54eaf\"}"\n
-                \n
+                event: block
+                data: {"slot":"10", "block":"0x9a2fefd2fdb57f74993c7780ea5b9030d2897b615b89f808011ca5aebed54eaf"}
             attestation:
               description: The node has received a valid attestation (from P2P or API)
               value: |
-                event: attestation\n
-                data: "{\n      \"aggregation_bits\": \"0x01\",\n      \"signature\": \"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505\",\n      \"data\": {\n        \"slot\": \"1\",\n        \"index\": \"1\",\n        \"beacon_block_root\": \"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2\",\n        \"source\": {\n          \"epoch\": \"1\",\n          \"root\": \"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2\"\n        },\n        \"target\": {\n          \"epoch\": \"1\",\n          \"root\": \"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2\"\n        }\n      }\n    }"\n
-                \n
+                event: attestation
+                data: {"aggregation_bits":"0x01", "signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505", "data":{"slot":"1", "index":"1", "beacon_block_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2", "source":{"epoch":"1", "root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"}, "target":{"epoch":"1", "root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"}}}
             voluntary_exit:
               description: The node has received a valid voluntary exit (from P2P or API)
               value: |
-                event: voluntary_exit\n
-                data: "{\n      \"message\": {\n        \"epoch\": \"1\",\n        \"validator_index\": \"1\"\n      },\n      \"signature\": \"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505\"\n    }"\n
-                \n
+                event: voluntary_exit
+                data: {"message":{"epoch":"1", "validator_index":"1"}, "signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"}
             finalized_checkpoint:
               description: Finalized checkpoint has been updated
               value: |
-                event: finalized_checkpoint\n
-                data: "{\"block\":\"0x9a2fefd2fdb57f74993c7780ea5b9030d2897b615b89f808011ca5aebed54eaf\", \"state\": \"0x600e852a08c1200654ddf11025f1ceacb3c2e74bdd5c630cde0838b2591b69f9\", \"epoch\": \"2\" }"\n
-                \n
+                event: finalized_checkpoint
+                data: {"block":"0x9a2fefd2fdb57f74993c7780ea5b9030d2897b615b89f808011ca5aebed54eaf", "state":"0x600e852a08c1200654ddf11025f1ceacb3c2e74bdd5c630cde0838b2591b69f9", "epoch":"2" }
             chain_reorg:
               description: The node has reorganized its chain
               value: |
-                event: chain_reorg\n
-                data: "{\"slot\":\"200\", \"depth\": \"50\", \"old_head_block\": \"0x9a2fefd2fdb57f74993c7780ea5b9030d2897b615b89f808011ca5aebed54eaf\", \"new_head_block\": \"0x76262e91970d375a19bfe8a867288d7b9cde43c8635f598d93d39d041706fc76\", \"old_head_state\":\"0x9a2fefd2fdb57f74993c7780ea5b9030d2897b615b89f808011ca5aebed54eaf\", \"new_head_state\": \"0x600e852a08c1200654ddf11025f1ceacb3c2e74bdd5c630cde0838b2591b69f9\", \"epoch\": \"2\" }"\n
-                \n
+                event: chain_reorg
+                data: {"slot":"200", "depth":"50", "old_head_block":"0x9a2fefd2fdb57f74993c7780ea5b9030d2897b615b89f808011ca5aebed54eaf", "new_head_block":"0x76262e91970d375a19bfe8a867288d7b9cde43c8635f598d93d39d041706fc76", "old_head_state":"0x9a2fefd2fdb57f74993c7780ea5b9030d2897b615b89f808011ca5aebed54eaf", "new_head_state":"0x600e852a08c1200654ddf11025f1ceacb3c2e74bdd5c630cde0838b2591b69f9", "epoch":"2"}
+            contribution_and_proof:
+              description: The node has received a valid sync committee SignedContributionAndProof (from P2P or API)
+              value: |
+                event: contribution_and_proof
+                data: {"message": {"aggregator_index": "997", "contribution": {"slot": "168097", "beacon_block_root": "0x56f1fd4262c08fa81e27621c370e187e621a67fc80fe42340b07519f84b42ea1", "subcommittee_index": "0", "aggregation_bits": "0xffffffffffffffffffffffffffffffff", "signature": "0x85ab9018e14963026476fdf784cc674da144b3dbdb47516185438768774f077d882087b90ad642469902e782a8b43eed0cfc1b862aa9a473b54c98d860424a702297b4b648f3f30bdaae8a8b7627d10d04cb96a2cc8376af3e54a9aa0c8145e3"}, "selection_proof": "0x87c305f04bfe5db27c2b19fc23e00d7ac496ec7d3e759cbfdd1035cb8cf6caaa17a36a95a08ba78c282725e7b66a76820ca4eb333822bd399ceeb9807a0f2926c67ce67cfe06a0b0006838203b493505a8457eb79913ce1a3bcd1cc8e4ef30ed"}, "signature": "0xac118511474a94f857300b315c50585c32a713e4452e26a6bb98cdb619936370f126ed3b6bb64469259ee92e69791d9e12d324ce6fd90081680ce72f39d85d50b0ff977260a8667465e613362c6d6e6e745e1f9323ec1d6f16041c4e358839ac"}
     "400":
       description: "The topics supplied could not be parsed"
       content: