Slack

Slack publishing runs through a hosted app. A workspace member installs it with OAuth, picks a channel, and that channel becomes an account you post to with POST /v1/posts using the platform id slack. You do not create a Slack app, host a bot or handle tokens. The same account receives DMs and mentions in the Inbox and can start a DM with any member of the workspace.

#What you can do

#Connect

Slack installs into a workspace, not a channel, so the flow ends with a channel choice. One connected account is one channel. To post in several channels, connect each as its own account.

curl "https://api.pozy.ai/v1/connect/slack?profileId=66a1f0c2a4b9d3e8f1a2b3c4&redirect_url=https://app.example.com/connected" \
  -H "Authorization: Bearer $POZY_API_KEY"

curl -X POST https://api.pozy.ai/v1/connect/slack \
  -H "Authorization: Bearer $POZY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "profileId": "66a1f0c2a4b9d3e8f1a2b3c4", "pendingDataToken": "'"$PENDING_DATA_TOKEN"'", "channelId": "C07ABCDEF12" }'

To add another channel from the same workspace, skip OAuth: call List Slack channels with an existing Slack accountId, then save with accountId instead of pendingDataToken.

Things that trip people up:

• Private channels. The app cannot join a private channel on its own. Someone in the channel must invite it first (type /invite in the channel and choose the app). Until then the channel does not appear in the list. Public channels are joined automatically.
• Admin approval. Some workspaces need an admin to approve new apps, so Slack may show a "request approval" screen.
• Unlisted app warning. Slack may say the app "has not been reviewed by Slack" during install. That is expected for apps that are not in the Slack Marketplace.

#Post types

A post with content becomes a message in the account's channel. There is no channelId field on a Slack post; sending one returns 400. To post somewhere else, connect that channel and use its accountId.

curl -X POST https://api.pozy.ai/v1/posts \
  -H "Authorization: Bearer $POZY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "content": "*Deploy finished* for `api` v2.4.1. Release notes: <https://example.com/notes|read here>",
    "platforms": [{
      "platform": "slack",
      "accountId": "66b2e19d8c3f5a7e9d0b1c2d",
      "platformSpecificData": { "unfurlLinks": false, "username": "Release Bot" }
    }],
    "publishNow": true
  }'

const res = await fetch("https://api.pozy.ai/v1/posts", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.POZY_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    content: "*Deploy finished* for `api` v2.4.1. Release notes: <https://example.com/notes|read here>",
    platforms: [{
      platform: "slack",
      accountId: "66b2e19d8c3f5a7e9d0b1c2d",
      platformSpecificData: { unfurlLinks: false, username: "Release Bot" },
    }],
    publishNow: true,
  }),
});
const data = await res.json();
if (!res.ok) throw new Error(data.error);
console.log(data.post.platforms[0].platformPostId);

import os, requests

resp = requests.post(
    "https://api.pozy.ai/v1/posts",
    headers={"Authorization": f"Bearer {os.environ['POZY_API_KEY']}"},
    json={
        "content": "*Deploy finished* for `api` v2.4.1. Release notes: <https://example.com/notes|read here>",
        "platforms": [{
            "platform": "slack",
            "accountId": "66b2e19d8c3f5a7e9d0b1c2d",
            "platformSpecificData": {"unfurlLinks": False, "username": "Release Bot"},
        }],
        "publishNow": True,
    },
)
print(resp.json()["post"]["platforms"][0]["platformPostId"])

To reply inside a thread, pass the parent message's timestamp as threadTs, for example "threadTs": "1503435956.000247". Scheduling happens in Pozy; Slack's own scheduler is not used.

#Platform fields

#Message identity

username and iconUrl change the name and avatar on one message. Set a default for every post from a channel with Update Slack account settings; the per-post fields still win. The override is cosmetic: Slack still shows an APP badge, and the app's own name stays in the sidebar.

#Media requirements

Up to 10 files per post, uploaded through Slack's file API with the text as the caption. Pozy does not compress or convert files for Slack, and there is no format allowlist: the bytes behind your URL reach Slack as they are.

Whether an upload succeeds depends on the workspace's upload policy and, on Slack's free plan, its storage cap. A file Slack refuses fails the post with Slack's message. Files are named from the media item: type: "video" uploads as .mp4, type: "gif" as .gif, anything else from filename. Media hosts files up to 5 GB.

#Limits

#Analytics

Slack has no public message analytics API, so Slack has no analytics in Pozy.

#Inbox

Slack events arrive in real time. The inbox takes in:

• DMs to the app
• Channel messages that @-mention the app
• Replies in threads the app is part of, including under posts you published
• Emoji reactions, as reaction.received

Ordinary channel conversation is not stored. The inbox is not a mirror of the workspace.

Each incoming message fires message.received, with metadata.threadTs when it is a thread reply and metadata.mentionsBot: true when it mentions the app. That pair is enough for the usual agent rule: always answer DMs, answer in a channel only when mentioned, reply in the thread.

Reply with Send message; replyTo threads the reply. Reactions use Add reaction with a named Slack emoji such as :thumbsup:.

To start a DM, find the member with List Slack workspace members and pass their member id as participantId to Create conversation:

curl "https://api.pozy.ai/v1/accounts/66b2e19d8c3f5a7e9d0b1c2d/slack-members?query=maria" \
  -H "Authorization: Bearer $POZY_API_KEY"

curl -X POST https://api.pozy.ai/v1/inbox/conversations \
  -H "Authorization: Bearer $POZY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "accountId": "66b2e19d8c3f5a7e9d0b1c2d", "participantId": "U04ABCDE123", "message": "Hi Maria, your report is ready." }'

const membersRes = await fetch("https://api.pozy.ai/v1/accounts/66b2e19d8c3f5a7e9d0b1c2d/slack-members?query=maria", {
  headers: { Authorization: `Bearer ${process.env.POZY_API_KEY}` },
});
const members = await membersRes.json();
if (!membersRes.ok) throw new Error(members.error);

const convoRes = await fetch("https://api.pozy.ai/v1/inbox/conversations", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.POZY_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({ accountId: "66b2e19d8c3f5a7e9d0b1c2d", participantId: "U04ABCDE123", message: "Hi Maria, your report is ready." }),
});
const convo = await convoRes.json();
if (!convoRes.ok) throw new Error(convo.error);
console.log(convo.data.conversationId);

headers = {"Authorization": f"Bearer {os.environ['POZY_API_KEY']}"}
members = requests.get(
    "https://api.pozy.ai/v1/accounts/66b2e19d8c3f5a7e9d0b1c2d/slack-members",
    headers=headers, params={"query": "maria"},
).json()

convo = requests.post(
    "https://api.pozy.ai/v1/inbox/conversations",
    headers=headers,
    json={"accountId": "66b2e19d8c3f5a7e9d0b1c2d", "participantId": "U04ABCDE123", "message": "Hi Maria, your report is ready."},
).json()
print(convo["data"]["conversationId"])

Bots, deactivated members and Slackbot are left out of the member lookup.

Constraints to plan for:

• No history backfill. The inbox starts when the channel connects.
• Messages from other bots appear for context but never trigger automations or webhooks.
• Attachments appear as links that open in Slack.
• People who DM the app become contacts; people talking in a channel do not. Built-in automations (workflows, sequences) run on DMs only. For channels, react to message.received with your own logic.

#Errors you may see

Errors covers the error format.

#Endpoints

#Webhook events