Node.js Setup

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Upgrading to v6.0?

Please see our upgrade path documentation.

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Any issues?

Integrations can be tricky! Contact support if you have any questions/issues.

Overview

If you're a developer, it takes a few small steps to send your API logs to ReadMe so your team can get deep insights into your API's usage with ReadMe Metrics. Here's an overview of how the integration works:

  • You add the Node.js SDK to your server manually or via the included Express.js middleware.
  • The Node.js SDK sends ReadMe the details of your API's incoming requests and outgoing responses, with the option for you to redact any private parameters or headers.
  • ReadMe uses these request and response details to populate Metrics charts which can be used to analyze specific API calls or monitor aggregate usage data.

Express.js Integration

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Note: If you're not using Express.js, check out our example integrations for hapi or Fastify here.

  1. Locate the file in your organization's API codebase that contains your Express server; often this file is named express.js, app.js, or server.js. You can also search your codebase for express() as that's where Express will be usually instantiated from.
  2. From the directory of this codebase, run the following command in your command line to install the readmeio package from npm:
npm install readmeio --save
  1. Load the readmeio module into your Express server. Usually near the beginning of the file, you will see several import or require statements. Add the following statement to that group:

Typescript

import * as readme from 'readmeio';

Node.js

const readme = require('readmeio');
  1. Configure the following middleware function:
app.use((req, res, next) => {
  readme.log(readmeAPIKey, req, res, {
    // You might extract this from a header or parameter.
    apiKey: req.<apiKey>,

    // You might extract these from user data associated with the API key.
    label: req.<userNameToShowInDashboard>,
    email: req.<userEmailAddress>,
  });

  return next();
});

For more details about the parameters you can provide to the express function, refer to the Express.js documentation.

  1. Test a request:
curl -i {my api url}

You should see a response header x-documentation-url. This header contains a URL to a detailed log of the API request/response. For info on configuring this header, check out the Documentation URL docs.

log Reference

The log function accepts the following parameters:

Note that this middleware is not likely to be sensitive to order. If you are new to Express, see How to Write Middleware for Express.js Apps.

ParameterRequired?Description
readmeAPIKeyyesThe API key for your ReadMe project. This ensures your requests end up in your dashboard. You can read more about the API key in our docs.
reqyesThe incoming Request object from Express.
resyesThe outgoing Response object from Express.
groupFnyesA function that helps translate incoming request data to our metrics grouping data. You can read more under Grouping Function.
optionsnoAdditional options. You can read more under Additional Express Options

Example

readme.log(readmeAPIKey, req, res, groupFn, options);

Grouping Function

The grouping function is a function your script should include that extracts identifying information out of the req object. While only apiKey is required, we recommend providing all three values to get the most out of the metrics dashboard.

Return data:

FieldRequired?TypeUsage
apiKeyyesstringAPI Key used to make the request. Note that this is different from the readmeAPIKey described above and should be a value from your API that is unique to each of your users.
labelnostringThis will be the user's display name in the API Metrics Dashboard, since it's much easier to remember a name than an API key.
emailnostringEmail of the user that is making the call.

Example

app.use((req, res, next) => {
  readme.log(readmeAPIKey, req, res, {
    // You might extract this from a header or parameter.
    apiKey: req.<apiKey>,

    // You might extract these from user data associated with the API key.
    label: req.<userNameToShowInDashboard>,
    email: req.<userEmailAddress>,
  });

  return next();
});

Additional Express Options

OptionTypeDescription
allowlistArray of stringsIf included, denylist will be ignored and all parameters but those in this list will be redacted.
baseLogUrlstringThis value is used when building the x-documentation-url header (see docs below). It is your ReadMe documentation's base URL (e.g. https://example.readme.com). If not provided, we will make one API call a day to determine your base URL (more info in Documentation URL. If provided, we will use that value and never look it up automatically.
bufferLengthnumberDefaults to 1. This value should be a number representing the amount of requests to group up before sending them over the network. Increasing this value will increase performance but delay the time until logs show up in the dashboard. The default value is 1.
denylistArray of stringsAn array of parameter names that will be redacted from the query parameters, request body (when JSON or form-encoded), response body (when JSON) and headers. For nested request parameters use dot notation (e.g. a.b.c to redact the field c within { a: { b: { c: 'foo' }}}).
developmentboolDefaults to false. When true, the log will be marked as a development log. This is great for separating staging or test data from data coming from customers.
fireAndForgetboolDefaults to true. When false, the server will wait for the response from the metrics call. This will be slower, but the response is useful in debugging problems.

Example

{
  denyList: ['password', 'secret'],
  development: true,
  fireAndForget: true,
  bufferLength: 1,
  baseLogUrl: "https://example.readme.com"
}

Documentation URL

With the middleware loaded, all requests that funneled through it will receive a x-documentation-url header applied to the response. The value of this header will be the URL on ReadMe Metrics with which you can view the log for that request.

Note that in order to generate this URL, an API request is made to ReadMe once a day, and cached to a local file in node_modules/.cache/readmeio, to retrieve your projects baseUrl. If this request to ReadMe fails, the x-documentation-url header will not be added to responses.

If you wish to not rely on this cache, you can opt to supply a baseLogUrl option into the middleware, which should evaluate to the public-facing URL of your ReadMe project.

Security

By default API keys sent the grouping function and Authorization headers are encrypted into an integrity hash using the ssri library. In order for us to safely utilize this data later in your ReadMe dashboards, and allow you to do user tracing, we pluck the last 4 characters off of the end of the encrypted string and save that with the integrity hash.

For example if the API key is 1999e4893f732ba38b948dbe8d34ed48cd54f058 we will include f058 on the end of the hash, resulting in ReadMe Metrics recording the following in our database:

sha512-/0bFzsk3a5wrmdTxA6qstL9TExGVTr9BUgZvhIjVrTa2M/KsNkW+AF8wJtgYd1OIvHc5qGgB9WfUbCA8PPbE8w==?f058

Sample Applications

FAQ

Are there any limitations?

  • Though we offer allowlist and denylist options for suppressing data you send to API Metrics, they are only supported on JSON and form-encoded request bodies. If you need to suppression support for other request body types you can parse the request body yourself and supply that modified payload into the log function where you'd send us req.

How can I upgrade to v6.0?

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If you are already using readme.log() as your entry point for recording API Metrics you don't need to do change anything.

With the v6 release of our Node SDK we've heavily simplified how the library can be implemented across every available JS web framework out there.

Given a readme.express() code snippet that looks like the following:

app.use(
  readme.express(readmeAPIKey, req => ({
    apiKey: req.<apiKey>,
    label: req.<userNameToShowInDashboard>,
    email: req.<userEmailAddress>,
  }))
);

You should change your implementation to use our new readme.log() method, resulting in something that looks like this:

app.use((req, res, next) => {
  readme.log(readmeAPIKey, req, res, {
    apiKey: req.<apiKey>,
    label: req.<userNameToShowInDashboard>,
    email: req.<userEmailAddress>,
  });

  return next();
});

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