github/copilot-sdk · error · InvalidOperationException

Failed to register GitHub token provider.

Error message

Failed to register GitHub token provider.

What it means

Thrown as InvalidOperationException when the client fails to record a GitHub token provider in its internal concurrent registry, i.e. the ConcurrentDictionary.TryAdd of a freshly generated GUID registration ID unexpectedly fails. Since the ID is a new Guid.NewGuid() string, this practically indicates an internal state problem (ID collision or corrupted registry).

Solutions

1. Retry the session creation — a GUID collision is effectively impossible to repeat
2. If reproducible, inspect whether custom code touched the client's internal registry or subclassed the client
3. Create a fresh CopilotClient instance and retry; report a bug if it persists
4. Ensure the provider delegate itself is not null/throwing before registration

Example fix

// before
var session = await client.CreateSessionAsync(new SessionConfig { GitHubTokenProvider = p });
// after
try { var session = await client.CreateSessionAsync(new SessionConfig { GitHubTokenProvider = p }); }
catch (InvalidOperationException ex) when (ex.Message.Contains("token provider")) { client = new CopilotClient(options); /* retry */ }

if (provider is null) throw new ArgumentNullException(nameof(provider));

try { session = await client.CreateSessionAsync(cfg); }
catch (InvalidOperationException ex) when (ex.Message.Contains("Failed to register GitHub token provider"))
{ client = new CopilotClient(opts); session = await client.CreateSessionAsync(cfg); }

When it happens

Trigger: Creating a session with config.GitHubTokenProvider set, during RegisterGitHubTokenProvider, when _gitHubTokenProviders.TryAdd(registrationId, provider) returns false for a brand-new GUID key.

Common situations: Extremely rare in practice — would require a GUID collision or a manually seeded registry with the same key; may appear if client internals were modified or if the client instance is being used in an unexpected/disposed state.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

• CopilotClient is in Mode = CopilotClientMode.Empty but the…
• session.create response did not include a sessionId.
• session.create returned sessionId
• Failed to delete session
• {response.Error ?? "Failed to set foreground session"}

AI-assisted analysis of github/copilot-sdk@cd8cf15dc3 (2026-09-09). Data as JSON: /api/errors/7be77088d15cba1e. Report an issue: GitHub.

Appendix: source

Thrown at dotnet/src/Client.cs:2079

        {
            throw new ArgumentException(
                $"{nameof(SessionConfigBase.GitHubToken)} and {nameof(SessionConfigBase.GitHubTokenProvider)} cannot be used together.",
                nameof(config));
        }
    }

    private string? RegisterGitHubTokenProvider(
        Func<GitHubTokenProviderArgs, Task<GitHubTokenProviderResult>>? provider)
    {
        if (provider is null)
        {
            return null;
        }

        var registrationId = Guid.NewGuid().ToString();
        if (!_gitHubTokenProviders.TryAdd(registrationId, provider))
        {
            throw new InvalidOperationException("Failed to register GitHub token provider.");
        }
        return registrationId;
    }

    internal void UnregisterGitHubTokenProvider(string registrationId)
        => _gitHubTokenProviders.TryRemove(registrationId, out _);

    private void ClearGitHubTokenProviders() => _gitHubTokenProviders.Clear();

    private sealed class GitHubTokenAdapter(CopilotClient client) : IGitHubTokenHandler
    {
        public async Task<GitHubTokenAcquireResult> GetTokenAsync(
            GitHubTokenAcquireRequest request,
            CancellationToken cancellationToken = default)
        {
            if (!client._gitHubTokenProviders.TryGetValue(request.RegistrationId, out var provider))
            {
                throw new InvalidOperationException(

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