Configuration Reference

ClaudeCodeSessionOptions properties

Property	Type	Default	Description
ApiKey	string?	null	Explicit Anthropic API key (sk-ant-api*). Highest priority — overrides all other sources.
OAuthToken	string?	null	Explicit OAuth token (sk-ant-oat*). Overrides environment variables and credentials file.
CredentialsPath	string?	null	Custom path to .credentials.json. When null, defaults to ~/.claude/.credentials.json.

The configuration section name is "ClaudeSession" (ClaudeCodeSessionOptions.SectionName).

---

JSON configuration (appsettings.json)

{
  "ClaudeSession": {
    "ApiKey": "",
    "OAuthToken": "",
    "CredentialsPath": ""
  }
}

Bind via IConfiguration:

services.AddClaudeCodeAuthentication(configuration);
// reads configuration.GetSection("ClaudeSession")

Typical production setup — leave all three empty and let the package resolve credentials from the environment or credentials file:

{
  "ClaudeSession": {}
}

---

Environment variables

Variable	Equivalent option	Description
ANTHROPIC_API_KEY	ApiKey	Standard Anthropic API key. Checked after explicit options.
CLAUDE_CODE_OAUTH_TOKEN	OAuthToken	OAuth token injected from outside the credentials file.

ANTHROPIC_API_KEY takes priority over CLAUDE_CODE_OAUTH_TOKEN when both are set.

---

Full credential resolution order (reminder)

1. ClaudeCodeSessionOptions.ApiKey
2. ClaudeCodeSessionOptions.OAuthToken
3. ANTHROPIC_API_KEY  (environment)
4. CLAUDE_CODE_OAUTH_TOKEN  (environment)
5. ~/.claude/.credentials.json  (Claude Code local session)

See Credential Resolution for detailed behaviour.

---

Default model

The modelId parameter on UseClaudeCodeChatCompletion() defaults to "claude-sonnet-4-6". It is passed at the call site rather than in ClaudeCodeSessionOptions, keeping auth concerns separate from model selection.

// Use default model
builder.UseClaudeCodeChatCompletion();

// Override model at the call site
builder.UseClaudeCodeChatCompletion("claude-opus-4-6");

---

Secrets management

For production deployments, avoid storing tokens in appsettings.json. Instead:

• Azure Key Vault — use builder.Configuration.AddAzureKeyVault(...) and map secrets to ClaudeSession:ApiKey
• Docker secrets / Kubernetes secrets — mount as env vars (ANTHROPIC_API_KEY) or as a file (CredentialsPath pointing to a mounted secret file)
• ASP.NET Core user-secrets (development only) — dotnet user-secrets set "ClaudeSession:ApiKey" "sk-ant-api..."

---

CI/CD example

# GitHub Actions
env:
  ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}

No code changes required — the package reads ANTHROPIC_API_KEY automatically.