Longbridge OpenAPI SDK for C

longbridge provides an easy-to-use interface for invoking Longbridge OpenAPI.

Documentation

SDK docs: https://longbridge.github.io/openapi/c/index.html
Longbridge OpenAPI: https://open.longbridge.com/en/

Examples

Runnable examples live in examples/c/:

examples/c/account_asset/main.c
examples/c/get_quote/main.c
examples/c/http_client/main.c
examples/c/subscribe_quote/main.c
examples/c/submit_order/main.c
examples/c/today_orders/main.c

Quickstart

Install Longbridge OpenAPI SDK

Download C SDK

Authentication

Longbridge OpenAPI supports two authentication methods:

1. OAuth 2.0 (Recommended)

OAuth 2.0 is the modern authentication method that uses Bearer tokens without requiring HMAC signatures.

Step 1: Register OAuth Client

First, register an OAuth client to get your client_id:

bash / macOS / Linux

curl -X POST https://openapi.longbridge.com/oauth2/register \
  -H "Content-Type: application/json" \
  -d '{
    "client_name": "My Application",
    "redirect_uris": ["http://localhost:60355/callback"],
    "grant_types": ["authorization_code", "refresh_token"]
  }'

PowerShell (Windows)

Invoke-RestMethod -Method Post -Uri https://openapi.longbridge.com/oauth2/register `
  -ContentType "application/json" `
  -Body '{
    "client_name": "My Application",
    "redirect_uris": ["http://localhost:60355/callback"],
    "grant_types": ["authorization_code", "refresh_token"]
  }'

Response:

{
  "client_id": "your-client-id-here",
  "client_secret": null,
  "client_name": "My Application",
  "redirect_uris": ["http://localhost:60355/callback"]
}

Save the client_id for use in your application.

Step 2: Build OAuth client and create a Config

lb_oauth_new loads a cached token from ~/.longbridge/openapi/tokens/<client_id> (%USERPROFILE%\.longbridge\openapi\tokens\<client_id> on Windows) if one exists and is still valid, or starts the browser authorization flow automatically. The token is persisted to the same path after a successful authorization or refresh. The resulting lb_oauth_t* handle is passed directly to lb_config_from_oauth.

#include <longbridge.h>
#include <stdio.h>

static void
on_open_url(const char* url, void* userdata)
{
  printf("Open this URL to authorize: %s\n", url);
}

static void
on_oauth_ready(const struct lb_async_result_t* res)
{
  if (res->error) {
    printf("OAuth failed: %s\n", lb_error_message(res->error));
    return;
  }

  lb_oauth_t* oauth = (lb_oauth_t*)res->data;
  lb_config_t* config = lb_config_from_oauth(oauth);
  // Use config to create contexts...
  lb_config_free(config);
  lb_oauth_free(oauth);
}

int
main(int argc, char const* argv[])
{
  lb_oauth_new("your-client-id", 0, on_open_url, NULL, on_oauth_ready, NULL);
  getchar();
  return 0;
}

2. Legacy API Key (Environment Variables)

Setting environment variables(MacOS/Linux)

export LONGBRIDGE_APP_KEY="App Key get from user center"
export LONGBRIDGE_APP_SECRET="App Secret get from user center"
export LONGBRIDGE_ACCESS_TOKEN="Access Token get from user center"

Setting environment variables(Windows)

setx LONGBRIDGE_APP_KEY "App Key get from user center"
setx LONGBRIDGE_APP_SECRET "App Secret get from user center"
setx LONGBRIDGE_ACCESS_TOKEN "Access Token get from user center"

Other environment variables

Name	Description
LONGBRIDGE_LANGUAGE	Language identifier, `zh-CN`, `zh-HK` or `en` (Default: `en`)
LONGBRIDGE_HTTP_URL	HTTP endpoint url (Default: `https://openapi.longbridge.com`)
LONGBRIDGE_QUOTE_WS_URL	Quote websocket endpoint url (Default: `wss://openapi-quote.longbridge.com/v2`)
LONGBRIDGE_TRADE_WS_URL	Trade websocket endpoint url (Default: `wss://openapi-trade.longbridge.com/v2`)
LONGBRIDGE_ENABLE_OVERNIGHT	Enable overnight quote, `true` or `false` (Default: `false`)
LONGBRIDGE_PUSH_CANDLESTICK_MODE	`realtime` or `confirmed` (Default: `realtime`)
LONGBRIDGE_PRINT_QUOTE_PACKAGES	Print quote packages when connected, `true` or `false` (Default: `true`)
LONGBRIDGE_LOG_PATH	Set the path of the log files (Default: `no logs`)

Quote API (Get basic information of securities)

#include <longbridge.h>
#include <stdio.h>
#ifdef WIN32
#include <windows.h>
#endif

static void
on_quote(const struct lb_async_result_t* res)
{
  if (res->error) {
    printf("failed to get quote: %s\n", lb_error_message(res->error));
    return;
  }

  lb_security_quote_t* data = (lb_security_quote_t*)res->data;
  for (int i = 0; i < res->length; i++) {
    const lb_security_quote_t* quote = &data[i];
    printf("%s timestamp=%lld last_done=%f open=%f high=%f low=%f volume=%lld "
           "turnover=%f\n",
           quote->symbol,
           quote->timestamp,
           lb_decimal_to_double(quote->last_done),
           lb_decimal_to_double(quote->open),
           lb_decimal_to_double(quote->high),
           lb_decimal_to_double(quote->low),
           quote->volume,
           lb_decimal_to_double(quote->turnover));
  }
}

static void
on_oauth_ready(const struct lb_async_result_t* res)
{
  if (res->error) {
    printf("OAuth failed: %s\n", lb_error_message(res->error));
    return;
  }

  lb_oauth_t* oauth = (lb_oauth_t*)res->data;
  lb_config_t* config = lb_config_from_oauth(oauth);
  const lb_quote_context_t* ctx = lb_quote_context_new(config);
  lb_config_free(config);
  lb_oauth_free(oauth);

  const char* symbols[] = { "700.HK", "AAPL.US", "TSLA.US", "NFLX.US" };
  lb_quote_context_quote(ctx, symbols, 4, on_quote, NULL);
}

static void
on_open_url(const char* url, void* userdata)
{
  printf("Open this URL to authorize: %s\n", url);
}

int
main(int argc, char const* argv[])
{
#ifdef WIN32
  SetConsoleOutputCP(CP_UTF8);
#endif

  lb_oauth_new("your-client-id", 0, on_open_url, NULL, on_oauth_ready, NULL);
  getchar();
  return 0;
}

Quote API (Subscribe quotes)

#include <longbridge.h>
#include <stdio.h>
#ifdef WIN32
#include <windows.h>
#endif

static void
on_quote(const struct lb_quote_context_t* ctx,
         const struct lb_push_quote_t* quote,
         void* userdata)
{
  printf("%s timestamp=%lld last_done=%f open=%f high=%f low=%f volume=%lld "
         "turnover=%f\n",
         quote->symbol,
         quote->timestamp,
         lb_decimal_to_double(quote->last_done),
         lb_decimal_to_double(quote->open),
         lb_decimal_to_double(quote->high),
         lb_decimal_to_double(quote->low),
         quote->volume,
         lb_decimal_to_double(quote->turnover));
}

static void
on_subscribe(const struct lb_async_result_t* res)
{
  if (res->error) {
    printf("failed to subscribe: %s\n", lb_error_message(res->error));
  }
}

static void
on_oauth_ready(const struct lb_async_result_t* res)
{
  if (res->error) {
    printf("OAuth failed: %s\n", lb_error_message(res->error));
    return;
  }

  lb_oauth_t* oauth = (lb_oauth_t*)res->data;
  lb_config_t* config = lb_config_from_oauth(oauth);
  const lb_quote_context_t* ctx = lb_quote_context_new(config);
  lb_config_free(config);
  lb_oauth_free(oauth);

  lb_quote_context_set_on_quote(ctx, on_quote, NULL, NULL);

  const char* symbols[] = { "700.HK", "AAPL.US", "TSLA.US", "NFLX.US" };
  lb_quote_context_subscribe(ctx, symbols, 4, LB_SUBFLAGS_QUOTE, on_subscribe, NULL);
}

static void
on_open_url(const char* url, void* userdata)
{
  printf("Open this URL to authorize: %s\n", url);
}

int
main(int argc, char const* argv[])
{
#ifdef WIN32
  SetConsoleOutputCP(CP_UTF8);
#endif

  lb_oauth_new("your-client-id", 0, on_open_url, NULL, on_oauth_ready, NULL);
  getchar();
  return 0;
}

Trade API (Submit order)

#include <longbridge.h>
#include <stdio.h>
#ifdef WIN32
#include <windows.h>
#endif

static void
on_submit_order(const struct lb_async_result_t* res)
{
  if (res->error) {
    printf("failed to submit order: %s\n", lb_error_message(res->error));
    return;
  }

  const lb_submit_order_response_t* resp = res->data;
  printf("order id: %s\n", resp->order_id);
}

static void
on_oauth_ready(const struct lb_async_result_t* res)
{
  if (res->error) {
    printf("OAuth failed: %s\n", lb_error_message(res->error));
    return;
  }

  lb_oauth_t* oauth = (lb_oauth_t*)res->data;
  lb_config_t* config = lb_config_from_oauth(oauth);
  const lb_trade_context_t* ctx = lb_trade_context_new(config);
  lb_config_free(config);
  lb_oauth_free(oauth);

  lb_decimal_t* submitted_price = lb_decimal_from_double(50.0);
  lb_decimal_t* submitted_quantity = lb_decimal_from_double(200.0);
  lb_submit_order_options_t opts = {
    "700.HK",       OrderTypeLO,
    OrderSideBuy,   submitted_quantity,
    TimeInForceDay, submitted_price,
    NULL,           NULL,
    NULL,           NULL,
    NULL,           NULL,
    NULL,
  };
  lb_decimal_free(submitted_price);
  lb_decimal_free(submitted_quantity);
  lb_trade_context_submit_order(ctx, &opts, on_submit_order, NULL);
}

static void
on_open_url(const char* url, void* userdata)
{
  printf("Open this URL to authorize: %s\n", url);
}

int
main(int argc, char const* argv[])
{
#ifdef WIN32
  SetConsoleOutputCP(CP_UTF8);
#endif

  lb_oauth_new("your-client-id", 0, on_open_url, NULL, on_oauth_ready, NULL);
  getchar();
  return 0;
}

Troubleshooting

Windows setx requires a new terminal; use set for the current cmd.exe session.
If you don't see callbacks, keep the process alive (examples use getchar()).
If building on Linux/macOS, ensure ncurses is installed (examples link it on non-Windows).
For debugging, set LONGBRIDGE_LOG_PATH to enable SDK logs.

License

Licensed under either of

Apache License, Version 2.0,(LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT) at your option.

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Longbridge OpenAPI SDK for C

Documentation

Examples

Quickstart

Authentication

1. OAuth 2.0 (Recommended)

2. Legacy API Key (Environment Variables)

Other environment variables

Quote API (Get basic information of securities)

Quote API (Subscribe quotes)

Trade API (Submit order)

Troubleshooting

License

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README.md

Latest commit

History

README.md

File metadata and controls

Longbridge OpenAPI SDK for C

Documentation

Examples

Quickstart

Authentication

1. OAuth 2.0 (Recommended)

2. Legacy API Key (Environment Variables)

Other environment variables

Quote API (Get basic information of securities)

Quote API (Subscribe quotes)

Trade API (Submit order)

Troubleshooting

License