Error reading server preface

mohuangnpc · November 14, 2025, 6:55am

I built a minimal blockchain project using Ignite and successfully ran Ignite Chain Serve. Sending tokens to addresses as instructed in the tutorial also worked fine. However, the REST API is malfunctioning; accessing any address on port 1317 results in the following error message:

curl xxxx/cosmos/base/tendermint/v1beta1/node_info

{ “code”: 14, “message”: “connection error: desc = “error reading server preface: EOF””, “details”: }

The program appears to be running normally.

Blockchain is running. :: Alice’s account address: cosmos1gm854qshrd22dj9lrj26sqmvw0at2tr5jqzpmk :: Bob’s account address: cosmos1nufjqs3qqaj7hhcegtktffyjxvt9es4fecn4l8 :: Tendermint node: xxxxx :: Blockchain API: xxxxxx :: Token faucet: xxxxx⋆ Data directory: /home/mohuang/.checkers ⋆ App binary: /home/mohuang/go/bin/checkersd Press the ‘q’ key to stop serving

What could be causing this? I’ve also checked the app.toml file.

app-db-backend = “”
halt-height = 0
halt-time = 0
iavl-cache-size = 781250
iavl-disable-fastnode = false
index-events =
inter-block-cache = true
min-retain-blocks = 0
minimum-gas-prices = “0stake”
pruning = “default”
pruning-interval = “0”
pruning-keep-recent = “0”
query-gas-limit = “0”

[api]
address = “tcp://0.0.0.0:1317”
enable = true
enabled-unsafe-cors = true
#max-open-connections = 1000
#rpc-max-body-bytes = 1000000
#rpc-read-timeout = 10
#rpc-write-timeout = 0
swagger = true

[grpc]
address = “0.0.0.0:9090”
enable = true
max-recv-msg-size = “10485760”
max-send-msg-size = “2147483647”

[grpc-web]
enable = true

[mempool]
max-txs = -1

[rpc]
cors_allowed_origins = [“*”]

[state-sync]
snapshot-interval = 0
snapshot-keep-recent = 2

[streaming]

[streaming.abci]
keys =
plugin = “”
stop-node-on-err = true

[telemetry]
datadog-hostname = “”
enable-hostname = false
enable-hostname-label = false
enable-service-label = false
enabled = false
global-labels =
metrics-sink = “”
prometheus-retention-time = 0
service-name = “”
statsd-addr = “”

I’ve searched through a lot of information, but I still have no clue.

cosmosrescue · November 14, 2025, 7:09am

hey, what do you mean by “accessing any address on port 1317“? which endpoints do you actually call?
on the same machine where the blockchain is running something like this should work

curl http://127.0.0.1:1317/cosmos/base/tendermint/v1beta1/node_info

mohuangnpc · November 14, 2025, 7:20am

Thanks for your reply. I’m unable to access any of the REST API addresses, even though the ports appear to be open. For example, when I try to access

curl x.x.x.x:1317/cosmos/base/tendermint/v1beta1/node_info

I get an error message.

root@node01:/home/mohuang/sdk# curl x.x.x.x:1317/cosmos/base/tendermint/v1beta1/node_info

{“code”:14,“message”:“connection error: desc = “error reading server preface: EOF””,“details”:}

I couldn’t reply with the address, so I’m using X instead.

cosmosrescue · November 14, 2025, 8:16am

well, i don’t get it, what is “any of the REST API addresses“? could you explain what you are doing exactly?

does this work from the same machine where the blockchain node is running?
curl http://127.0.0.1:1317/cosmos/base/tendermint/v1beta1/node_info
are you trying to call this endpoint from another machine and x.x.x.x is ip address of the machine where the blockchain node is running?

mohuangnpc · November 14, 2025, 8:32am

I apologize, perhaps my wording was inaccurate. The address you provided is inaccessible; accessing it will result in the following message:

{“code”:14,“message”:“connection error: desc = “error reading server preface: EOF””,“details”:}

and it’s not accessing from another machine, but from the local machine.

cosmosrescue · November 14, 2025, 8:37am

hm, alright, could you share output of

curl -v http://127.0.0.1:1317/cosmos/base/tendermint/v1beta1/node_info

mohuangnpc · November 14, 2025, 8:42am

Of course you can. I don’t know why I can’t upload images. This is the result I got when I executed “curl your address” in the command line.

root@node01:/home/mohuang/sdk# curl -v xxxxx:/cosmos/base/tendermint/v1beta1/node_info

Trying 127.0.0.1:1317…

Connected to 127.0.0.1 (127.0.0.1) port 1317

using HTTP/1.x

GET /cosmos/base/tendermint/v1beta1/node_info HTTP/1.1
Host: 127.0.0.1:1317
User-Agent: curl/8.14.1
Accept: /

Request completely sent off
< HTTP/1.1 503 Service Unavailable
< Content-Type: application/json
< X-Server-Time: 1763109653
< Date: Fri, 14 Nov 2025 08:40:53 GMT
< Content-Length: 99
<

Connection #0 to host 127.0.0.1 left intact
{“code”:14,“message”:“connection error: desc = “error reading server preface: EOF””,“details”:}

cosmosrescue · November 14, 2025, 8:44am

alright, your config might have an issue, could you try adding tcp to grpc part of the config, then redeploy the chain and try again?

[grpc]
address = "tcp://0.0.0.0:9090"

mohuangnpc · November 14, 2025, 8:46am

This is my app.toml configuration; gRPC itself is 0.0.0.0:9090.

app-db-backend = “”
halt-height = 0
halt-time = 0
iavl-cache-size = 781250
iavl-disable-fastnode = false
index-events =
inter-block-cache = true
min-retain-blocks = 0
minimum-gas-prices = “0stake”
pruning = “default”
pruning-interval = “0”
pruning-keep-recent = “0”
query-gas-limit = “0”

[api]
address = “tcp://0.0.0.0:1317”
enable = true
enabled-unsafe-cors = true
#max-open-connections = 1000
#rpc-max-body-bytes = 1000000
#rpc-read-timeout = 10
#rpc-write-timeout = 0
swagger = true

[grpc]
address = “0.0.0.0:9090”
enable = true
max-recv-msg-size = “10485760”
max-send-msg-size = “2147483647”

[grpc-web]
enable = true

[mempool]
max-txs = -1

[rpc]
cors_allowed_origins = [“*”]

[state-sync]
snapshot-interval = 0
snapshot-keep-recent = 2

[streaming]

[streaming.abci]
keys =
plugin = “”
stop-node-on-err = true

[telemetry]
datadog-hostname = “”
enable-hostname = false
enable-hostname-label = false
enable-service-label = false
enabled = false
global-labels =
metrics-sink = “”
prometheus-retention-time = 0
service-name = “”
statsd-addr = “”

cosmosrescue · November 14, 2025, 8:47am

yes, so try to change it to

[grpc]
address = "tcp://0.0.0.0:9090"

redeploy the chain and try calling rest endpoint again

mohuangnpc · November 14, 2025, 8:55am

[grpc]
address = “tcp://0.0.0.0:9090”
enable = true
max-recv-msg-size = “10485760”
max-send-msg-size = “2147483647”

After modifying the configuration and re-running ignite chain serve, I still get the same error message

cosmosrescue · November 14, 2025, 9:01am

alright, a few questions:

when you redeploy the chain - are there logs similar to the ones below? could you share complete startup logs?

INFO Starting gRPC server on tcp://0.0.0.0:9090
INFO Starting REST server on tcp://0.0.0.0:1317

is there any output of this (needs net-tools installed)

ss -tlnp | grep -E ':(1317|9090)'

what is the output of

curl -v http://localhost:1317/swagger/

mohuangnpc · November 14, 2025, 9:08am

This is the startup log.:

Blockchain is running

alice’s account address: cosmos1gm854qshrd22dj9lrj26sqmvw0at2tr5jqzpmk
bob’s account address: cosmos1nufjqs3qqaj7hhcegtktffyjxvt9es4fecn4l8

Tendermint node: 0.0.0.0:26657
Blockchain API: 0.0.0.0:1317
Token faucet: 0.0.0.0:4500

⋆ Data directory: /home/mohuang/.checkers
⋆ App binary: /home/mohuang/go/bin/checkersd

This is a port check:

root@node01:/home/mohuang/sdk# lsof -i:1317
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
checkersd 176978 mohuang 36u IPv6 288642 0t0 TCP *:1317 (LISTEN)
root@node01:/home/mohuang/sdk# lsof -i:9090
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
checkersd 176978 mohuang 37u IPv6 291969 0t0 TCP *:9090 (LISTEN)

This is the result of the address access:

root@node01:/home/mohuang/sdk# curl -v localhost:1317/swagger/

Host localhost:1317 was resolved.

IPv6: ::1

IPv4: 127.0.0.1

Trying [::1]:1317…

Connected to localhost (::1) port 1317

using HTTP/1.x

GET /swagger/ HTTP/1.1
Host: localhost:1317
User-Agent: curl/8.14.1
Accept: /

Request completely sent off
< HTTP/1.1 200 OK
< Accept-Ranges: bytes
< Content-Length: 1466
< Content-Type: text/html; charset=utf-8
< X-Server-Time: 1763111272
< Date: Fri, 14 Nov 2025 09:07:52 GMT
<

Swagger UI html { box-sizing: border-box; overflow: -moz-scrollbars-vertical; overflow-y: scroll; }

  *,
  *:before,
  *:after
  {
    box-sizing: inherit;
  }

  body
  {
    margin:0;
    background: #fafafa;
  }
</style>

<script src="./swagger-ui-bundle.js" charset="UTF-8"> </script>
<script src="./swagger-ui-standalone-preset.js" charset="UTF-8"> </script>
<script>
window.onload = function() {
  // Begin Swagger UI call region
  const ui = SwaggerUIBundle({
    url: "./swagger.yaml",
    dom_id: '#swagger-ui',
    deepLinking: true,
    queryConfigEnabled: false,
    presets: [
      SwaggerUIBundle.presets.apis,
      SwaggerUIStandalonePreset
    ],
    plugins: [
      SwaggerUIBundle.plugins.DownloadUrl
    ],
    layout: "StandaloneLayout"
  });
  // End Swagger UI call region

  window.ui = ui;
};

* Connection #0 to host localhost left intact

cosmosrescue · November 14, 2025, 9:18am

alright, so by the looks of it - grpc connection is the issue - why it matters is because rest endpoint calls grpc internally, so if grpc doesn’t work - rest won’t work either.

could you try calling grpc directly (needs grpcurl installed):

grpcurl --plaintext localhost:9090 list

cosmosrescue · November 14, 2025, 9:25am

and also could you try this and redeploy the chain (to force ipv4 over ipv6, to narrow it down since networking is likely the issue):

[grpc]
address = "tcp://127.0.0.1:9090"

mohuangnpc · November 14, 2025, 9:30am

This is the result of the gRPC call; it looks fine. I’ll redeploy later and force IPv4 to try it out.

root@node01:/home/mohuang# grpcurl --plaintext localhost:9090 list
checkers.checkers.v1.Query
cosmos.app.v1alpha1.Query
cosmos.auth.v1beta1.Query
cosmos.authz.v1beta1.Query
cosmos.autocli.v1.Query
cosmos.bank.v1beta1.Query
cosmos.base.node.v1beta1.Service
cosmos.base.reflection.v1beta1.ReflectionService
cosmos.base.reflection.v2alpha1.ReflectionService
cosmos.base.tendermint.v1beta1.Service
cosmos.circuit.v1.Query
cosmos.consensus.v1.Query
cosmos.distribution.v1beta1.Query
cosmos.epochs.v1beta1.Query
cosmos.evidence.v1beta1.Query
cosmos.feegrant.v1beta1.Query
cosmos.gov.v1.Query
cosmos.gov.v1beta1.Query
cosmos.group.v1.Query
cosmos.mint.v1beta1.Query
cosmos.nft.v1beta1.Query
cosmos.params.v1beta1.Query
cosmos.reflection.v1.ReflectionService
cosmos.slashing.v1beta1.Query
cosmos.staking.v1beta1.Query
cosmos.tx.v1beta1.Service
cosmos.upgrade.v1beta1.Query
grpc.reflection.v1alpha.ServerReflection
ibc.applications.interchain_accounts.controller.v1.Query
ibc.applications.interchain_accounts.host.v1.Query
ibc.applications.transfer.v1.Query
ibc.core.channel.v1.Query
ibc.core.channel.v2.Query
ibc.core.client.v1.Query
ibc.core.client.v2.Query
ibc.core.connection.v1.Query

cosmosrescue · November 14, 2025, 9:33am

yeah, it looks good.
so let’s try with address = “tcp://127.0.0.1:9090” and if it still doesn’t work after redeployment - could you share results of lsof -i:9090 again. binding could be system dependent, so we want to check if it is ipv4 with this setting

mohuangnpc · November 14, 2025, 10:54am

Oh my god, it seems to be working.

mohuangnpc · November 14, 2025, 10:55am

I set it to tcp1270019090, and it seems to be working.

mohuangnpc · November 14, 2025, 10:56am

But it seems I can’t access it using other IPs.

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Error reading server preface

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