Upwork

C# SDK for the official Upwork GraphQL API, focused on OAuth2 authorization and read-only marketplace job search.

Features

• OAuth2 Authorization Code Grant and Refresh Token Grant
• Authorization URL builder for https://www.upwork.com/ab/account-security/oauth2/authorize
• Token exchange against https://www.upwork.com/api/v3/oauth2/token
• GraphQL client for https://api.upwork.com/graphql using Authorization: Bearer
• Optional X-Upwork-API-TenantId header support
• companySelector helper for organization context discovery
• marketplaceJobPostingsSearch wrapper with cursor pagination and sort attributes
• marketplaceJobPosting wrapper for expanded job details
• marketplaceJobPostingsContents wrapper for job detail/content lookup
• Typed DTOs for marketplace job IDs, title, description, published date, ciphertext, annotations, skills, budget/hourly/client/proposal fields when returned by Upwork
• GraphQL missing-scope exception handling and HTTP 429 rate-limit hooks
• Source-generated JSON serialization for trimming and NativeAOT compatibility

No mutation helpers are exposed for this OAuth/job-search workflow.

Required Scopes

Select these scopes in the Upwork app/key settings for this read-only job-search use case:

• Common Entities - Read-Only Access
• Read marketplace Job Postings

OAuth

Build an authorization URL from environment variables:

using Upwork;

var clientId =
    Environment.GetEnvironmentVariable("UPWORK_CLIENT_ID") is { Length: > 0 } clientIdValue
        ? clientIdValue
        : throw new InvalidOperationException("UPWORK_CLIENT_ID is required.");
var clientSecret =
    Environment.GetEnvironmentVariable("UPWORK_CLIENT_SECRET") is { Length: > 0 } clientSecretValue
        ? clientSecretValue
        : throw new InvalidOperationException("UPWORK_CLIENT_SECRET is required.");
var redirectUri =
    Environment.GetEnvironmentVariable("UPWORK_REDIRECT_URI") is { Length: > 0 } redirectValue
        ? new Uri(redirectValue)
        : throw new InvalidOperationException("UPWORK_REDIRECT_URI is required.");

var oauthConfig = new UpworkOAuthConfig(clientId, clientSecret, redirectUri);
using var oauth = new UpworkOAuthClient(oauthConfig);

var authorizationUrl = oauth.CreateAuthorizationUri(
    state: Environment.GetEnvironmentVariable("UPWORK_OAUTH_STATE"));

Exchange an authorization code:

var authorizationCode =
    Environment.GetEnvironmentVariable("UPWORK_AUTHORIZATION_CODE") is { Length: > 0 } codeValue
        ? codeValue
        : throw new InvalidOperationException("UPWORK_AUTHORIZATION_CODE is required.");

var token = await oauth.ExchangeAuthorizationCodeAsync(authorizationCode);

Refresh an access token:

var refreshToken =
    Environment.GetEnvironmentVariable("UPWORK_REFRESH_TOKEN") is { Length: > 0 } refreshValue
        ? refreshValue
        : throw new InvalidOperationException("UPWORK_REFRESH_TOKEN is required.");

var refreshedToken = await oauth.RefreshTokenAsync(refreshToken);

The SDK returns tokens but does not persist them. Store accessToken, refreshToken, and expiry metadata in your application.

Job Search

Use a bearer token from your own token store:

using Upwork;

var accessToken =
    Environment.GetEnvironmentVariable("UPWORK_ACCESS_TOKEN") is { Length: > 0 } accessTokenValue
        ? accessTokenValue
        : throw new InvalidOperationException("UPWORK_ACCESS_TOKEN is required.");
var tenantId = Environment.GetEnvironmentVariable("UPWORK_TENANT_ID");

using var client = new UpworkClient(
    new UpworkClientOptions
    {
        AccessToken = accessToken,
        TenantId = string.IsNullOrWhiteSpace(tenantId) ? null : tenantId,
    });

var selector = await client.GetCompanySelectorAsync();

var jobs = await client.SearchMarketplaceJobPostingsAsync(
    UpworkMarketplaceJobFilters.Keywords("dotnet graphql", first: 10) with
    {
        VerifiedPaymentOnly = true,
    },
    sortAttributes:
    [
        new UpworkMarketplaceJobPostingSearchSort(
            UpworkMarketplaceJobPostingSearchSortFields.Recency),
    ]);

var firstJobId = jobs.Edges?
    .Select(edge => edge.Node?.Id)
    .FirstOrDefault(id => id is { Length: > 0 });

if (firstJobId is { Length: > 0 })
{
    var contents = await client.GetMarketplaceJobPostingsContentsAsync([firstJobId]);
}

Read expanded job fields from search results or direct detail lookup:

var search = await client.SearchMarketplaceJobPostingsAsync(
    UpworkMarketplaceJobFilters.Keywords("csharp backend", first: 5));

foreach (var edge in search.Edges ?? [])
{
    var result = edge.Node;
    var posting = result?.Job;
    var hourlyTerms = posting?.ContractTerms?.HourlyContractTerms;
    var fixedPriceTerms = posting?.ContractTerms?.FixedPriceContractTerms;
    var skills = posting?.Classification?.Skills?
        .Select(skill => skill.PreferredLabel)
        .Where(skill => skill is { Length: > 0 });

    Console.WriteLine(result?.Title ?? posting?.Content?.Title);
    Console.WriteLine($"Hourly: {hourlyTerms?.HourlyBudgetMin}-{hourlyTerms?.HourlyBudgetMax}");
    Console.WriteLine($"Fixed: {fixedPriceTerms?.Amount?.DisplayValue}");
    Console.WriteLine($"Client: {posting?.ClientCompanyPublic?.City}, {posting?.ClientCompanyPublic?.State}");
    Console.WriteLine($"Activity: {posting?.ActivityStat?.JobActivity?.TotalHired} hires");
    Console.WriteLine($"Skills: {string.Join(", ", skills ?? [])}");
}

var detailJobId = search.Edges?
    .Select(edge => edge.Node?.Id)
    .FirstOrDefault(id => id is { Length: > 0 });

if (detailJobId is { Length: > 0 })
{
    var posting = await client.GetMarketplaceJobPostingAsync(detailJobId);
    var questions = posting?.ContractorSelection?.ProposalRequirement?.ScreeningQuestions;

    foreach (var question in questions ?? [])
    {
        Console.WriteLine(question.Question);
    }
}

For backend-owned token storage, implement IUpworkAccessTokenProvider and pass it through UpworkClientOptions.AccessTokenProvider.

Rate Limits

HTTP 429 responses throw UpworkRateLimitException with RetryAfter when Upwork sends that header. To retry, provide an IUpworkRateLimitHandler and set MaxRateLimitRetries.

Migration Notes

• Replace direct REST/OAuth code with UpworkOAuthConfig and UpworkOAuthClient.
• Store tokens in your backend database or secret store; the SDK does not persist secrets.
• Refresh tokens with RefreshTokenAsync before access-token expiry and update stored tokens atomically.
• Use GetCompanySelectorAsync to discover organization context, then set TenantId when your workflow requires X-Upwork-API-TenantId.
• Use SearchMarketplaceJobPostingsAsync; do not use deprecated marketplaceJobPostings.
• Use GetMarketplaceJobPostingAsync for expanded job details, or GetMarketplaceJobPostingsContentsAsync for bulk content lookup.
• Handle UpworkMissingScopeException by asking the user/admin to grant Common Entities - Read-Only Access and Read marketplace Job Postings.
• Handle UpworkRateLimitException or configure IUpworkRateLimitHandler for retry/backoff.
• Do not log or persist authorization codes, access tokens, refresh tokens, client secrets, or full Authorization headers.

Support

Priority place for bugs: https://github.com/tryAGI/Upwork/issues
Priority place for ideas and general questions: https://github.com/tryAGI/Upwork/discussions