Configuration

Node Type Registration

The executor class SlackNodeExecutor is registered in ExecutorRegistry under two type codes so it can be dropped onto a canvas either way:

Dependency Registration

Register everything the node needs with a single call in Program.cs / Startup.cs:

builder.Services.AddSlackNodeExecutor();

AddSlackNodeExecutor() (on SlackDependency) registers, in order:

1. IOperationGuard via AddOperationGuard() — required by SlackChannelService for rate/credit guarding.
2. All Slack HTTP services via AddSlackIntegration() — ISlackChatService, SlackMessageService, SlackChannelService, SlackFileService, SlackReactionService, SlackUserService, SlackUserGroupService — each with a typed HttpClient.
3. SlackNodeExecutor itself, scoped.
4. Both ExecutorRegistry entries (slack, slack-message).

Hosts that auto-discover plugins via AddExecutorPluginsFromAssembly() do not need to call this explicitly — SlackDependency implements INodeExecutorDependency and is picked up automatically.

HTTP Client Timeouts

Rate Limiting

Every typed HttpClient above has SlackRateLimitHandler attached as a DelegatingHandler. On an HTTP 429 response it reads the Retry-After header (falling back to 30 seconds if absent) and retries automatically, up to 3 attempts, before surfacing the final 429 to the caller. This is transparent to every operation on this node — no per-operation configuration is required.

Credential Resolution

Every operation DTO derives from BaseSlackOperationInfo, which carries two credential-related fields:

Resolution priority, implemented in SlackNodeExecutor.ApplyBotTokenAsync:

1. If credentialID is set, resolve the bearer token from the vault. Missing resolver or missing credential both return a structured error (CREDENTIAL_RESOLVER_NOT_CONFIGURED / CREDENTIAL_NOT_FOUND).
2. Otherwise, use the inline botToken config value.
3. If neither resolves to a non-empty token, the operation fails with MISSING_BOT_TOKEN.

Shared Config Keys

Every operation reads three keys before any operation-specific fields:

Output Ports

ValidateExecutorSettings() ensures every Slack node instance has both standard output ports created via GetOrCreatePortSuccessAndError(): a success port and an error port. Every operation partial writes to exactly one of the two. See Input & Output for the full result shape.