Symbology client library for .NET

The FactSet Symbology API provides symbol resolution services, allowing clients to translate market identifiers into various symbology types such as, FactSet Permanent Identifiers, CUSIP, ISIN, SEDOL, Tickers, and LEIs.

Factset's Symbology API sits at the center of its hub-and-spoke data model, enabling you to quickly harmonize the expanding catalog of Content APIs.

This API is rate-limited to 10 requests per second and 10 concurrent requests per user.

This .NET package is automatically generated by the OpenAPI Generator project:

• API version: 3.5.0
• SDK version: 5.0.0
• Build package: com.factset.sdk.codegen.FactSetCSharpNetCoreClientCodegen

Requirements

• .NET Standard >= 2.0

Installation

.NET CLI

dotnet add package FactSet.SDK.Utils dotnet add package FactSet.SDK.Symbology -v 5.0.0

NuGet

nuget install FactSet.SDK.Utils nuget install FactSet.SDK.Symbology -Version 5.0.0

Usage

1. Generate authentication credentials.
2. Setup .NET Standard 2.0 compatible environment.
3. Install dependencies.
4. Run the following:

[!IMPORTANT] The parameter variables defined below are just examples and may potentially contain non valid values. Please replace them with valid values.

Example Code

using System; using System.Threading.Tasks; using FactSet.SDK.Utils.Authentication; using FactSet.SDK.Symbology.Api; using FactSet.SDK.Symbology.Client; using FactSet.SDK.Symbology.Model; namespace Example { public static class BatchHistoricalIdentifierResolutionExample { public static async Task Main() { var config = new FactSet.SDK.Symbology.Client.Configuration(); // Examples for each supported authentication method are below, // choose one that satisfies your use case. /* (Preferred) OAuth 2.0: FactSetOAuth2 */ // See https://github.com/FactSet/enterprise-sdk#oauth-20 // for information on how to create the app-config.json file // // The confidential client instance should be reused in production environments. // See https://github.com/FactSet/enterprise-sdk-utils-dotnet#authentication // for more information on using the ConfidentialClient class ConfidentialClient confidentialClient = await ConfidentialClient.CreateAsync("/path/to/app-config.json"); config.OAuth2Client = confidentialClient; /* Basic authentication: FactSetApiKey */ // See https://github.com/FactSet/enterprise-sdk#api-key // for information how to create an API key // config.Username = "USERNAME-SERIAL"; // config.Password = "API-KEY"; var apiInstance = new HistoricalIdentifierResolutionApi(config); var identifierResolutionHistoricalRequest = new IdentifierResolutionHistoricalRequest(); // IdentifierResolutionHistoricalRequest | Request Body for Historical Identifier Resolution. try { // Returns the specified historical output identifiers for the given input identifier. IdentifierResolutionHistoricalResponse result = apiInstance.BatchHistoricalIdentifierResolution(identifierResolutionHistoricalRequest); Console.WriteLine(result.ToJson()); } catch (ApiException e) { Console.WriteLine("Exception when calling HistoricalIdentifierResolutionApi.BatchHistoricalIdentifierResolution: " + e.Message ); Console.WriteLine("Status Code: "+ e.ErrorCode); Console.WriteLine(e.StackTrace); } } } }

Using a Proxy

To use the API client with a HTTP proxy, setup a System.Net.WebProxy

Configuration c = new Configuration(); System.Net.WebProxy webProxy = new System.Net.WebProxy("http://myProxyUrl:80/"); webProxy.Credentials = System.Net.CredentialCache.DefaultCredentials; c.Proxy = webProxy;

Documentation for API Endpoints

All URIs are relative to https://api.factset.com/content

Class	Method	HTTP request	Description
HistoricalIdentifierResolutionApi	BatchHistoricalIdentifierResolution	POST /symbology/v3/historical-identifier-resolution	Returns the specified historical output identifiers for the given input identifier.
HistoricalIdentifierResolutionApi	HistoricalIdentifierResolution	GET /symbology/v3/historical-identifier-resolution	Returns the specified historical output identifiers for the given input identifier.
IdentifierResolutionApi	BatchIdentifierResolution	POST /symbology/v3/identifier-resolution	Returns the specified output identifiers for the given input identifier.
IdentifierResolutionApi	IdentifierResolution	GET /symbology/v3/identifier-resolution	Returns the specified output identifiers for the specified input identifier.

Documentation for Models

• Model.ErrorObject
• Model.ErrorObjectLinks
• Model.ErrorResponse
• Model.ErrorResponseHistorical
• Model.ErrorResponseSubErrors
• Model.GetHistoricalInputSymbolType
• Model.GetInputSymbolType
• Model.IdentifierResolution
• Model.IdentifierResolutionHistorical
• Model.IdentifierResolutionHistoricalRequest
• Model.IdentifierResolutionHistoricalRequestBody
• Model.IdentifierResolutionHistoricalResponse
• Model.IdentifierResolutionRequest
• Model.IdentifierResolutionResponse

Documentation for Authorization

FactSetApiKey

• Type: HTTP basic authentication

FactSetOAuth2

• Type: OAuth
• Flow: application
• Authorization URL:
• Scopes: N/A

Contributing

Please refer to the contributing guide.

Copyright

Copyright 2026 FactSet Research Systems Inc

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.