log10ts

The Log10 typescript library provides convenient access and type safe models for managing requests and responses from the Log10 REST API powered by fetch.

Summary

Log10 Feedback API Spec: Log10 Feedback API Spec

Table of Contents

• SDK Installation
• Requirements
• SDK Example Usage
• Available Resources and Operations
• Standalone functions
• Retries
• Error Handling
• Server Selection
• Custom HTTP Client
• Authentication
• Debugging

SDK Installation

The SDK can be installed with either npm, pnpm, bun or yarn package managers.

NPM

npm add log10ts

PNPM

pnpm add log10ts

Bun

bun add log10ts

Yarn

yarn add log10ts zod

# Note that Yarn does not install peer dependencies automatically. You will need
# to install zod as shown above.

Example

Here is a regular OpenAI call, traced with log10.

import OpenAI from "openai";

import { SDKOptions } from "log10ts";
import { Log10Wrapper } from "log10ts/wrapper";

const options: SDKOptions = {
  log10Token: process.env["LOG10_TOKEN"] || "",
  xLog10Organization: process.env["LOG10_ORG_ID"] || "",
  serverURL: "https://log10.io",
};

const client = new OpenAI({
  apiKey: process.env["OPENAI_API_KEY"],
});
const wrapper = new Log10Wrapper(options, ["unique-tag-id"]);
wrapper.wrap(client);

async function main() {
  const response = await client.chat.completions.create({
    messages: [{ role: "user", content: "Knock knock - who is there?" }],
    model: "gpt-3.5-turbo",
  });

  console.log(response);
}

main();

Adding feedback

Start by adding a feedback task. This is a logical grouping of feedback and defines the expected feedback schema i.e. acceptable values.

import { Log10, SDKOptions } from "log10ts";

const options: SDKOptions = {
  log10Token: process.env["LOG10_TOKEN"] || "",
  xLog10Organization: process.env["LOG10_ORG_ID"] || "",
  serverURL: "https://log10.io",
};

const log10 = new Log10(options);

async function run() {
  const taskSchema = {
    $schema: "http://json-schema.org/draft-07/schema#",
    title: "Summary Evaluation",
    type: "object",
    properties: {
      relevance: {
        type: "integer",
        minimum: 1,
        maximum: 7,
        description:
          "The relevance of the summary to the content being summarized, rated from 1 (least relevant) to 7 (most relevant)",
      },
      coherence: {
        type: "integer",
        minimum: 1,
        maximum: 7,
        description:
          "The coherence and logical flow of the summary, rated from 1 (least coherent) to 7 (most coherent)",
      },
    },
    required: ["relevance", "coherence"],
    additionalProperties: false,
  };

  const task = {
    organizationId: process.env["LOG10_ORG_ID"] || "",
    jsonSchema: taskSchema,
    name: "Test Task",
    instruction: "Test Instruction",
    completionTagsSelector: ["test"],
  };

  const result = await log10.feedbackTasks.create(task);

  // Handle the result
  console.log("Task id: ", result?.task?.id);
}

run();

This should create a task and print out the id. Save this for adding feedback.

Now, with a task and logged completion, you can now add feedback:

import { Log10, SDKOptions } from "log10ts";

const options: SDKOptions = {
  log10Token: process.env["LOG10_TOKEN"] || "",
  xLog10Organization: process.env["LOG10_ORG_ID"] || "",
  serverURL: "https://log10.io",
};

const log10 = new Log10(options);

async function run() {
  const taskID = "<<REPLACE WITH YOUR TASK ID>>";

  const feedback = {
    organizationId: process.env["LOG10_ORG_ID"] || "",
    taskId: taskID,
    jsonValues: {
      relevance: 5,
      coherence: 6,
    },
    comment: "",
    completionTagsSelector: ["unique-tag-id"],
  };

  const result = await log10.feedbackSDK.upload(feedback);

  // Handle the result
  console.log("Result: ", result);
}

run();

SDK Example Usage

Example

import { Log10 } from "log10ts";

const log10 = new Log10({
  log10Token: "<YOUR_API_KEY_HERE>",
});

async function run() {
  const result = await log10.sessions.create();

  // Handle the result
  console.log(result);
}

run();

Available Resources and Operations

completions

• create - Create a completion
• update - Update completion by id.
• listUngraded - List ungraded completions i.e. completions that have not been associated with feedback but matches task selector.

feedback

• get - Fetch feedback by id.
• upload - Upload a piece of feedback

feedbackTasks

• list - List feedback tasks.
• create - Create a new task.
• get - Retrieves feedback task taskId.

sessions

• create - Create a session

Error Handling

All SDK methods return a response object or throw an error. By default, an API error will throw a models.SDKError.

If a HTTP request fails, an operation my also throw an error from the models/httpclienterrors.ts module:

| HTTP Client Error | Description | | ---------------------------------------------------- | ---------------------------------------------------- | | RequestAbortedError | HTTP request was aborted by the client | | RequestTimeoutError | HTTP request timed out due to an AbortSignal signal | | ConnectionError | HTTP client was unable to make a request to a server | | InvalidRequestError | Any input used to create a request is invalid | | UnexpectedClientError | Unrecognised or unexpected error |

In addition, when custom error responses are specified for an operation, the SDK may throw their associated Error type. You can refer to respective Errors tables in SDK docs for more details on possible error types for each operation. For example, the create method may throw the following errors:

| Error Type | Status Code | Content Type | | --------------- | ----------- | ------------ | | models.SDKError | 4XX, 5XX | */* |

import {
  ChatCompletionRole,
  CreateChatCompletionRequestType,
  FinishReason,
  Kind,
  Log10,
  ObjectT,
} from "log10ts";
import { SDKValidationError } from "log10ts/models";

const log10 = new Log10({
  log10Token: "<YOUR_API_KEY_HERE>",
});

async function run() {
  let result;
  try {
    result = await log10.completions.create({
      organizationId: "<id>",
      kind: Kind.Chat,
      request: {
        messages: [
          {
            role: ChatCompletionRole.System,
          },
          {
            content: "<value>",
            role: ChatCompletionRole.Tool,
          },
        ],
        model: "gpt-4-turbo",
        n: 1,
        responseFormat: {
          type: CreateChatCompletionRequestType.JsonObject,
        },
        temperature: 1,
        topP: 1,
        user: "user-1234",
      },
      response: {
        id: "<id>",
        choices: [
          {
            finishReason: FinishReason.Stop,
            index: 169727,
            message: {
              content: "<value>",
              role: ChatCompletionRole.System,
            },
            logprobs: {
              content: [
                {
                  token: "<value>",
                  logprob: 8165.87,
                  bytes: [
                    752438,
                    957409,
                  ],
                  topLogprobs: [
                    {
                      token: "<value>",
                      logprob: 2596.30,
                      bytes: [
                        486589,
                      ],
                    },
                  ],
                },
                {
                  token: "<value>",
                  logprob: 2303.13,
                  bytes: [
                    638424,
                  ],
                  topLogprobs: [
                    {
                      token: "<value>",
                      logprob: 4174.58,
                      bytes: [
                        134365,
                      ],
                    },
                  ],
                },
                {
                  token: "<value>",
                  logprob: 3229.97,
                  bytes: [
                    69025,
                  ],
                  topLogprobs: [
                    {
                      token: "<value>",
                      logprob: 7964.74,
                      bytes: [
                        951062,
                      ],
                    },
                  ],
                },
              ],
            },
          },
          {
            finishReason: FinishReason.Stop,
            index: 651985,
            message: {
              content: "<value>",
              role: ChatCompletionRole.User,
            },
            logprobs: {
              content: [
                {
                  token: "<value>",
                  logprob: 0.87,
                  bytes: [
                    169727,
                  ],
                  topLogprobs: [
                    {
                      token: "<value>",
                      logprob: 899.64,
                      bytes: [
                        792620,
                      ],
                    },
                  ],
                },
              ],
            },
          },
          {
            finishReason: FinishReason.ContentFilter,
            index: 650237,
            message: {
              content: "<value>",
              role: ChatCompletionRole.User,
            },
            logprobs: {
              content: [
                {
                  token: "<value>",
                  logprob: 8165.87,
                  bytes: [
                    586220,
                  ],
                  topLogprobs: [
                    {
                      token: "<value>",
                      logprob: 7524.37,
                      bytes: [
                        957409,
                      ],
                    },
                  ],
                },
              ],
            },
          },
        ],
        created: 523523,
        model: "gpt-4-turbo",
        object: ObjectT.ChatCompletion,
      },
    });

    // Handle the result
    console.log(result);
  } catch (err) {
    switch (true) {
      case (err instanceof SDKValidationError): {
        // Validation errors can be pretty-printed
        console.error(err.pretty());
        // Raw value may also be inspected
        console.error(err.rawValue);
        return;
      }
      default: {
        throw err;
      }
    }
  }
}

run();

Validation errors can also occur when either method arguments or data returned from the server do not match the expected format. The SDKValidationError that is thrown as a result will capture the raw value that failed validation in an attribute called rawValue. Additionally, a pretty() method is available on this error that can be used to log a nicely formatted string since validation errors can list many issues and the plain error string may be difficult read when debugging.

Server Selection

Override Server URL Per-Client

The default server can also be overridden globally by passing a URL to the serverURL: string optional parameter when initializing the SDK client instance. For example:

import {
  ChatCompletionRole,
  CreateChatCompletionRequestType,
  FinishReason,
  Kind,
  Log10,
  ObjectT,
} from "log10ts";

const log10 = new Log10({
  serverURL: "https://log10.io",
  log10Token: "<YOUR_API_KEY_HERE>",
});

async function run() {
  const result = await log10.completions.create({
    organizationId: "<id>",
    kind: Kind.Chat,
    request: {
      messages: [
        {
          role: ChatCompletionRole.System,
        },
        {
          content: "<value>",
          role: ChatCompletionRole.Tool,
        },
      ],
      model: "gpt-4-turbo",
      n: 1,
      responseFormat: {
        type: CreateChatCompletionRequestType.JsonObject,
      },
      temperature: 1,
      topP: 1,
      user: "user-1234",
    },
    response: {
      id: "<id>",
      choices: [
        {
          finishReason: FinishReason.Stop,
          index: 169727,
          message: {
            content: "<value>",
            role: ChatCompletionRole.System,
          },
          logprobs: {
            content: [
              {
                token: "<value>",
                logprob: 8165.87,
                bytes: [
                  752438,
                  957409,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 2596.30,
                    bytes: [
                      486589,
                    ],
                  },
                ],
              },
              {
                token: "<value>",
                logprob: 2303.13,
                bytes: [
                  638424,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 4174.58,
                    bytes: [
                      134365,
                    ],
                  },
                ],
              },
              {
                token: "<value>",
                logprob: 3229.97,
                bytes: [
                  69025,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 7964.74,
                    bytes: [
                      951062,
                    ],
                  },
                ],
              },
            ],
          },
        },
        {
          finishReason: FinishReason.Stop,
          index: 651985,
          message: {
            content: "<value>",
            role: ChatCompletionRole.User,
          },
          logprobs: {
            content: [
              {
                token: "<value>",
                logprob: 0.87,
                bytes: [
                  169727,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 899.64,
                    bytes: [
                      792620,
                    ],
                  },
                ],
              },
            ],
          },
        },
        {
          finishReason: FinishReason.ContentFilter,
          index: 650237,
          message: {
            content: "<value>",
            role: ChatCompletionRole.User,
          },
          logprobs: {
            content: [
              {
                token: "<value>",
                logprob: 8165.87,
                bytes: [
                  586220,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 7524.37,
                    bytes: [
                      957409,
                    ],
                  },
                ],
              },
            ],
          },
        },
      ],
      created: 523523,
      model: "gpt-4-turbo",
      object: ObjectT.ChatCompletion,
    },
  });

  // Handle the result
  console.log(result);
}

run();

Custom HTTP Client

The TypeScript SDK makes API calls using an HTTPClient that wraps the native Fetch API. This client is a thin wrapper around fetch and provides the ability to attach hooks around the request lifecycle that can be used to modify the request or handle errors and response.

The HTTPClient constructor takes an optional fetcher argument that can be used to integrate a third-party HTTP client or when writing tests to mock out the HTTP client and feed in fixtures.

The following example shows how to use the "beforeRequest" hook to to add a custom header and a timeout to requests and how to use the "requestError" hook to log errors:

import { Log10 } from "log10ts";
import { HTTPClient } from "log10ts/lib/http";

const httpClient = new HTTPClient({
  // fetcher takes a function that has the same signature as native `fetch`.
  fetcher: (request) => {
    return fetch(request);
  }
});

httpClient.addHook("beforeRequest", (request) => {
  const nextRequest = new Request(request, {
    signal: request.signal || AbortSignal.timeout(5000)
  });

  nextRequest.headers.set("x-custom-header", "custom value");

  return nextRequest;
});

httpClient.addHook("requestError", (error, request) => {
  console.group("Request Error");
  console.log("Reason:", `${error}`);
  console.log("Endpoint:", `${request.method} ${request.url}`);
  console.groupEnd();
});

const sdk = new Log10({ httpClient });

Authentication

Per-Client Security Schemes

This SDK supports the following security scheme globally:

| Name | Type | Scheme | | ------------ | ------ | ------- | | log10Token | apiKey | API key |

To authenticate with the API the log10Token parameter must be set when initializing the SDK client instance. For example:

import {
  ChatCompletionRole,
  CreateChatCompletionRequestType,
  FinishReason,
  Kind,
  Log10,
  ObjectT,
} from "log10ts";

const log10 = new Log10({
  log10Token: "<YOUR_API_KEY_HERE>",
});

async function run() {
  const result = await log10.completions.create({
    organizationId: "<id>",
    kind: Kind.Chat,
    request: {
      messages: [
        {
          role: ChatCompletionRole.System,
        },
        {
          content: "<value>",
          role: ChatCompletionRole.Tool,
        },
      ],
      model: "gpt-4-turbo",
      n: 1,
      responseFormat: {
        type: CreateChatCompletionRequestType.JsonObject,
      },
      temperature: 1,
      topP: 1,
      user: "user-1234",
    },
    response: {
      id: "<id>",
      choices: [
        {
          finishReason: FinishReason.Stop,
          index: 169727,
          message: {
            content: "<value>",
            role: ChatCompletionRole.System,
          },
          logprobs: {
            content: [
              {
                token: "<value>",
                logprob: 8165.87,
                bytes: [
                  752438,
                  957409,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 2596.30,
                    bytes: [
                      486589,
                    ],
                  },
                ],
              },
              {
                token: "<value>",
                logprob: 2303.13,
                bytes: [
                  638424,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 4174.58,
                    bytes: [
                      134365,
                    ],
                  },
                ],
              },
              {
                token: "<value>",
                logprob: 3229.97,
                bytes: [
                  69025,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 7964.74,
                    bytes: [
                      951062,
                    ],
                  },
                ],
              },
            ],
          },
        },
        {
          finishReason: FinishReason.Stop,
          index: 651985,
          message: {
            content: "<value>",
            role: ChatCompletionRole.User,
          },
          logprobs: {
            content: [
              {
                token: "<value>",
                logprob: 0.87,
                bytes: [
                  169727,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 899.64,
                    bytes: [
                      792620,
                    ],
                  },
                ],
              },
            ],
          },
        },
        {
          finishReason: FinishReason.ContentFilter,
          index: 650237,
          message: {
            content: "<value>",
            role: ChatCompletionRole.User,
          },
          logprobs: {
            content: [
              {
                token: "<value>",
                logprob: 8165.87,
                bytes: [
                  586220,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 7524.37,
                    bytes: [
                      957409,
                    ],
                  },
                ],
              },
            ],
          },
        },
      ],
      created: 523523,
      model: "gpt-4-turbo",
      object: ObjectT.ChatCompletion,
    },
  });

  // Handle the result
  console.log(result);
}

run();

Standalone functions

All the methods listed above are available as standalone functions. These functions are ideal for use in applications running in the browser, serverless runtimes or other environments where application bundle size is a primary concern. When using a bundler to build your application, all unused functionality will be either excluded from the final bundle or tree-shaken away.

To read more about standalone functions, check FUNCTIONS.md.

• completionsCreate - Create a completion
• completionsListUngraded - List ungraded completions i.e. completions that have not been associated with feedback but matches task selector.
• completionsUpdate - Update completion by id.
• feedbackGet - Fetch feedback by id.
• feedbackTasksCreate - Create a new task.
• feedbackTasksGet - Retrieves feedback task taskId.
• feedbackTasksList - List feedback tasks.
• feedbackUpload - Upload a piece of feedback
• sessionsCreate - Create a session

Retries

Some of the endpoints in this SDK support retries. If you use the SDK without any configuration, it will fall back to the default retry strategy provided by the API. However, the default retry strategy can be overridden on a per-operation basis, or across the entire SDK.

To change the default retry strategy for a single API call, simply provide a retryConfig object to the call:

import {
  ChatCompletionRole,
  CreateChatCompletionRequestType,
  FinishReason,
  Kind,
  Log10,
  ObjectT,
} from "log10ts";

const log10 = new Log10({
  log10Token: "<YOUR_API_KEY_HERE>",
});

async function run() {
  const result = await log10.completions.create({
    organizationId: "<id>",
    kind: Kind.Chat,
    request: {
      messages: [
        {
          role: ChatCompletionRole.System,
        },
        {
          content: "<value>",
          role: ChatCompletionRole.Tool,
        },
      ],
      model: "gpt-4-turbo",
      n: 1,
      responseFormat: {
        type: CreateChatCompletionRequestType.JsonObject,
      },
      temperature: 1,
      topP: 1,
      user: "user-1234",
    },
    response: {
      id: "<id>",
      choices: [
        {
          finishReason: FinishReason.Stop,
          index: 169727,
          message: {
            content: "<value>",
            role: ChatCompletionRole.System,
          },
          logprobs: {
            content: [
              {
                token: "<value>",
                logprob: 8165.87,
                bytes: [
                  752438,
                  957409,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 2596.30,
                    bytes: [
                      486589,
                    ],
                  },
                ],
              },
              {
                token: "<value>",
                logprob: 2303.13,
                bytes: [
                  638424,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 4174.58,
                    bytes: [
                      134365,
                    ],
                  },
                ],
              },
              {
                token: "<value>",
                logprob: 3229.97,
                bytes: [
                  69025,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 7964.74,
                    bytes: [
                      951062,
                    ],
                  },
                ],
              },
            ],
          },
        },
        {
          finishReason: FinishReason.Stop,
          index: 651985,
          message: {
            content: "<value>",
            role: ChatCompletionRole.User,
          },
          logprobs: {
            content: [
              {
                token: "<value>",
                logprob: 0.87,
                bytes: [
                  169727,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 899.64,
                    bytes: [
                      792620,
                    ],
                  },
                ],
              },
            ],
          },
        },
        {
          finishReason: FinishReason.ContentFilter,
          index: 650237,
          message: {
            content: "<value>",
            role: ChatCompletionRole.User,
          },
          logprobs: {
            content: [
              {
                token: "<value>",
                logprob: 8165.87,
                bytes: [
                  586220,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 7524.37,
                    bytes: [
                      957409,
                    ],
                  },
                ],
              },
            ],
          },
        },
      ],
      created: 523523,
      model: "gpt-4-turbo",
      object: ObjectT.ChatCompletion,
    },
  }, {
    retries: {
      strategy: "backoff",
      backoff: {
        initialInterval: 1,
        maxInterval: 50,
        exponent: 1.1,
        maxElapsedTime: 100,
      },
      retryConnectionErrors: false,
    },
  });

  // Handle the result
  console.log(result);
}

run();

If you'd like to override the default retry strategy for all operations that support retries, you can provide a retryConfig at SDK initialization:

import {
  ChatCompletionRole,
  CreateChatCompletionRequestType,
  FinishReason,
  Kind,
  Log10,
  ObjectT,
} from "log10ts";

const log10 = new Log10({
  retryConfig: {
    strategy: "backoff",
    backoff: {
      initialInterval: 1,
      maxInterval: 50,
      exponent: 1.1,
      maxElapsedTime: 100,
    },
    retryConnectionErrors: false,
  },
  log10Token: "<YOUR_API_KEY_HERE>",
});

async function run() {
  const result = await log10.completions.create({
    organizationId: "<id>",
    kind: Kind.Chat,
    request: {
      messages: [
        {
          role: ChatCompletionRole.System,
        },
        {
          content: "<value>",
          role: ChatCompletionRole.Tool,
        },
      ],
      model: "gpt-4-turbo",
      n: 1,
      responseFormat: {
        type: CreateChatCompletionRequestType.JsonObject,
      },
      temperature: 1,
      topP: 1,
      user: "user-1234",
    },
    response: {
      id: "<id>",
      choices: [
        {
          finishReason: FinishReason.Stop,
          index: 169727,
          message: {
            content: "<value>",
            role: ChatCompletionRole.System,
          },
          logprobs: {
            content: [
              {
                token: "<value>",
                logprob: 8165.87,
                bytes: [
                  752438,
                  957409,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 2596.30,
                    bytes: [
                      486589,
                    ],
                  },
                ],
              },
              {
                token: "<value>",
                logprob: 2303.13,
                bytes: [
                  638424,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 4174.58,
                    bytes: [
                      134365,
                    ],
                  },
                ],
              },
              {
                token: "<value>",
                logprob: 3229.97,
                bytes: [
                  69025,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 7964.74,
                    bytes: [
                      951062,
                    ],
                  },
                ],
              },
            ],
          },
        },
        {
          finishReason: FinishReason.Stop,
          index: 651985,
          message: {
            content: "<value>",
            role: ChatCompletionRole.User,
          },
          logprobs: {
            content: [
              {
                token: "<value>",
                logprob: 0.87,
                bytes: [
                  169727,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 899.64,
                    bytes: [
                      792620,
                    ],
                  },
                ],
              },
            ],
          },
        },
        {
          finishReason: FinishReason.ContentFilter,
          index: 650237,
          message: {
            content: "<value>",
            role: ChatCompletionRole.User,
          },
          logprobs: {
            content: [
              {
                token: "<value>",
                logprob: 8165.87,
                bytes: [
                  586220,
                ],
                topLogprobs: [
                  {
                    token: "<value>",
                    logprob: 7524.37,
                    bytes: [
                      957409,
                    ],
                  },
                ],
              },
            ],
          },
        },
      ],
      created: 523523,
      model: "gpt-4-turbo",
      object: ObjectT.ChatCompletion,
    },
  });

  // Handle the result
  console.log(result);
}

run();

Debugging

You can setup your SDK to emit debug logs for SDK requests and responses.

You can pass a logger that matches console's interface as an SDK option.

[!WARNING] Beware that debug logging will reveal secrets, like API tokens in headers, in log messages printed to a console or files. It's recommended to use this feature only during local development and not in production.

import { Log10 } from "log10ts";

const sdk = new Log10({ debugLogger: console });

Development

Maturity

This SDK is in beta, and there may be breaking changes between versions without a major version update. Therefore, we recommend pinning usage to a specific package version. This way, you can install the same version each time without breaking changes unless you are intentionally looking for the latest version.

Contributions

While we value open-source contributions to this SDK, this library is generated programmatically. Feel free to open a PR or a Github issue as a proof of concept and we'll do our best to include it in a future release!

For supported JavaScript runtimes, please consult RUNTIMES.md.

Requirements

For supported JavaScript runtimes, please consult RUNTIMES.md.