Slack¶

Audience: Everyone · Tags: slack, connector, oauth

Post messages to a Slack channel from a flow. connectorKey is slack, action type send_message, authType is oauth, category communication.

Early access. This connector's code makes real calls to the Slack API — there's no separate sandbox or mock Slack behind it. It's been validated end-to-end in SnapLink's automated tests using fake/injected HTTP responses (so tests don't need a live Slack account), and the install → configure → certify → activate lifecycle, the action's request shape, and error handling all work as documented below. It just hasn't been exercised against a real Slack workspace yet — that additionally requires your administrator to register a real Slack OAuth app (client id/secret) with SnapLink. Until that's done, the connector installs and activates normally, but a live send returns error code auth.

Fields¶

Field	Required	Type	Notes
`channel`	Yes	string	A channel ID (e.g. `C0123456789`) or a name the bot can see (e.g. `#sales`).
`text`	Yes	string	The message text.

Output: ts — the Slack message timestamp (Slack's message identifier).

The text you write is sent exactly as written each time — SnapLink doesn't insert data from the incoming webhook into it.

Install and activate (marketplace walkthrough)¶

# 1. Install into your workspace
curl -X POST "https://api.snaplink.cloudsolutionaccelerators.com/api/v1/marketplace/installed" \
  -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
  -d '{"workspaceId":"ws_abc123","connectorKey":"slack"}'
# → 201 { "data": { "state": "installed", ... } }

# 2. Configure
curl -X POST "https://api.snaplink.cloudsolutionaccelerators.com/api/v1/marketplace/installed/transition" \
  -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
  -d '{"workspaceId":"ws_abc123","connectorKey":"slack","action":"configure"}'

# 3. Certify (runs a health check; must pass to advance)
curl -X POST "https://api.snaplink.cloudsolutionaccelerators.com/api/v1/marketplace/installed/transition" \
  -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
  -d '{"workspaceId":"ws_abc123","connectorKey":"slack","action":"certify"}'

# 4. Activate
curl -X POST "https://api.snaplink.cloudsolutionaccelerators.com/api/v1/marketplace/installed/transition" \
  -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
  -d '{"workspaceId":"ws_abc123","connectorKey":"slack","action":"activate"}'

To actually send messages, your admin also connects a real Slack bot token — via SnapLink's Slack OAuth flow once a Slack app is registered, or via the lower-level /connections API with credentialType: "oauth_access" for direct wiring.

Worked example¶

Flow: webhook trigger → Slack: Send Message

{
  "trigger": { "key": "t", "connectorKey": "webhook", "triggerType": "webhook" },
  "actions": [
    {
      "key": "a1",
      "connectorKey": "slack",
      "actionType": "send_message",
      "input": { "channel": "C0000000", "text": "New event received" }
    }
  ]
}

1. Create the flow and draft:

curl -X POST "https://api.snaplink.cloudsolutionaccelerators.com/api/v1/flows/flow_abc123/drafts" \
  -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
  -d '{"definition": { "trigger": {"key":"t","connectorKey":"webhook","triggerType":"webhook"}, "actions": [{"key":"a1","connectorKey":"slack","actionType":"send_message","input":{"channel":"C0000000","text":"New event received"}}] }}'

2. Promote it to activate (the flow won't validate until Slack is active in the workspace, per the lifecycle above):

curl -X POST "https://api.snaplink.cloudsolutionaccelerators.com/api/v1/drafts/draft_xyz/promote" \
  -H "Authorization: Bearer $TOKEN"

3. Trigger it (see webhook.md):

curl -X POST "https://api.snaplink.cloudsolutionaccelerators.com/api/v1/webhooks/flow_abc123/<secret>" \
  -H "Content-Type: application/json" -d '{}'

{ "ok": true, "data": { "runId": "run_01HF...", "status": "queued" } }

4. Check the run in Execution History. If a real Slack bot token is connected, the message posts to #sales (or whichever channel); otherwise the step fails with auth.

Limitations¶

Slack rate-limits messaging (roughly 1 message/second/channel); SnapLink maps throttling to rate_limit and can retry with backoff.
The bot must already be a member of (or invited to) private channels to post there.
Plain text messages only — Slack Block Kit / rich formatting is Planned.

If something goes wrong¶

Symptom	Cause	Fix
Run fails `auth`	No real Slack app registered yet, or the bot token was revoked	Ask your admin to complete Slack OAuth setup, or reconnect (Authentication errors)
`channel_not_found` / `not_in_channel`	Wrong channel ID, or the bot isn't in that channel	Use the channel's ID, or invite the bot
`rate_limit`	Sending too fast	Add backoff — see Rate limiting

See Connector failed for the general failure-diagnosis path.