A command line utility to talk to a tchannel server

Usage no npm install needed!

<script type="module">
  import tcurl from '';



A command line utility for sending requests to TChannel services.

(This project is no longer under active development. Check out yab instead.)

usage: tcurl <service> [--health | <method> [<body>]]
Sends one or more TChannel requests.
    The name of the TChannel/Hyperbahn service to send requests to.
    The name of the endpoint to send requests to or method to call.
  [<body>] :jshon
    The Thrift or JSON argument in SHON or JSON format.
  [--headers <head>] :jshon
    The application headers as SHON or JSON arguments.
  [-p|--peer <peer>...]
    The peer or peers to connect.
  [-P|--peerlist <path>]
    The path to a file containing a JSON list of peers.
    The -H and --hostlist flags are deprecated.
    Use the raw argument scheme.
  [--http <method>]
    Use the HTTP argument scheme with given method.
    Use the JSON argument scheme.
    The -J flag is deprecated.
  [-t|--thrift <thrift>]
    Where to find Thrift IDL files.
    Disable strict Thrift parsing.
  [--cn|--caller <cn>]
    Fake an alternate caller service name.
    tcurl is the default.
  [--sk|--shard-key <sk>]
    Ringpop shard key
    The --shardKey flag is deprecated.
  [--rd|--routing-delegate <rd>]
    Forward to the given service for application-specific routing.
  [--timeout <ms>]
    Timeout in milliseconds
  [--requests <count>]
    Number of requests to make
  [--rate <rate>]
    Request rate in requests per second
  [--delay <ms>]
    Delay between requests in milliseconds
  [--time <ms>]
    Benchmark duration in milliseconds
    Hit the health endpoint for the service
  [-h]* short help
  [--help]* man page
  [-v|--version]* print version

The [-3|--arg3|--body <body>] argument is deprecated
in favor of passing <body> as JSON or SHON as a positional argument.
The [-2|--arg2|--head <head>] argument is deprecated
in favor of the --headers <headers> argument with JSON or SHON.

Click here for full usage docs.


npm install tcurl



For the purposes of these examples, let's assume that you have a TChannel server listening on localhost:1234. The server registers handlers for the thrift interface saved as services/chamber.thrift and defined as:

struct EchoRequest {
  1: required string input;

service Chamber {
  string echo(
    1: required EchoRequest request;

You could use TCurl to query this service by running:

tcurl -p localhost:1234 chamber Chamber::echo -t ./services -3 '{"request": {"input": "foo"}}'

localhost caveat

For TChannel and Hyperbahn to work together effectively, most tchannel services need to listen on the external IP of the host they are running on.

This means when you use you cannot reach the service with tcurl as it's not listening on loopback.

To make supporting external IPs easier we've made localhost resolve to the external IP of the machine. This means if your listening on loopback you have to use and not localhost


TCurl can be configured with default parameters using a either /etc/tcurlrc or a .tcurlrc in the current working directory or any of its parent directories. The rc file may be in INI or JSON format.

    "hostlist": "/etc/ringpop/hosts.json"

Exit Codes

  • 0: for all successful requests
  • 1: timeout
  • 2: cancelled
  • 3: busy
  • 4: declined
  • 5: unexpected error
  • 6: bad request
  • 7: network error
  • 8: unhealthy (broken circuit)
  • 124: unhealthy / not OK thrift response
  • 125: misc tcurl / tchannel internal error
  • 126: response not ok error
  • 127: fatal protocol error

NPM scripts

  • npm run add-licence This will add the licence headers.
  • npm run cover This runs the tests with code coverage
  • npm run lint This will run the linter on your code
  • npm test This will run the tests.
  • npm run trace This will run your tests in tracing mode.
  • npm run travis This is run by travis.CI to run your tests
  • npm run view-cover This will show code coverage in a browser


  • Raynos
  • ShanniLi
  • kriskowal

MIT Licenced