Prepare and send Slack posts and replies with verified workspace, target, thread, audience, approval, duplicate-send protection, and read-back.
A Slack message can be perfectly written and still go to the wrong place. A copied channel name may resolve in another workspace. A thread reply may become a channel broadcast. An @channel mention can wake a customer-facing shared channel. A timed-out send may be retried and post twice.
Slack Messaging turns one communication request into a controlled message record. It verifies the workspace, authenticated actor, conversation ID, thread parent, external audience, mentions, links, attachments, and action before any send. Approval binds the exact revision. If a call becomes ambiguous, the workflow reconciles Slack evidence before allowing a retry.
The output is built for review: target and audience evidence, a source-faithful draft, message digest, approval scope, operation key, duplicate rule, execution record, read-back checks, blockers, and a truthful verdict. The included canonical JSON contract and read-only checker keep IDs, states, and verdict precedence consistent. The checker does not contact Slack, authorize a write, or prove that anyone read the message.
Version 1.0.0 was reviewed on 2026-07-17 and evaluated through Codex CLI with gpt-5.6-sol in 12 fresh read-only contexts. The candidate scored 100 across three cases, compared with 56.25 for the same agent without the skill and 60 for the exact free upstream. All cases passed. The candidate led the upstream by 50 points on a shared-channel incident preview, 46.25 points on a canonical approved thread reply, and 23.75 points on ambiguous-timeout recovery. The evaluation covers those supplied cases. It does not prove that a live workspace, target, audience, approval, or message matches supplied evidence.
The reviewed package SHA-256 is 6b96c657d67cce3c5c2fef73a5f3d99a9ca863c4846be6e9fbbdb0790733c17a. Maintenance and install support are handled by the platform-operated publisher for this listing.
Input
Post @channel in #customer-incidents that mitigation is complete. The channel is shared externally, but workspace, conversation ID, audience, link access, reconciliation, customer confirmation, and approval are not verified.
Output
A blocked plan that keeps the target and audience unknown, rejects the unsupported all-clear, requires exact Slack Connect and mention evidence, binds a future revision to a digest and operation key, and names one read-only next action.
Input
Create canonical JSON for one approved reply in workspace T01234567, channel C01234567, parent 1784281200.123456, with one user mention, reviewed link, final body hash, approval digest, and expiry. No send has run.
Provide the request reference, Slack workspace and authenticated actor if known, exact channel or DM, top-level or thread intent, parent message timestamp for replies, external or shared-channel context, mentions, links, attachments, final message or body hash, and the action you want: plan, draft, send, or recover. The skill stops before a write when target identity, audience expansion, content, approval, or prior-attempt evidence is incomplete.
An installed Slack connector, MCP server, CLI, or app with documented identity, read, draft, send, reply, search, and read-back capabilities appropriate to the requested action.
Workspace and actor evidence, stable channel or DM ID, current conversation type and audience, and parent message timestamp for a thread reply.
Source facts, exact draft or body hash, links and access state, attachments or Canvas identities, mentions, broadcast or schedule intent, and explicit approval for the exact mutation.
Permission to read the target conversation and inspect safe message metadata after a send or ambiguous attempt.
SKILL.md; controlled Slack planning, drafting, sending, verification, and recovery workflow; canonical message-record contract; read-only message-record checker; Agent Skills interface metadata
No reviews yet.
Output
A machine-checkable ready-to-send record with exact workspace, actor, target, thread, mention, link, revision, approval, operation key, null execution identifiers, and a truthful planned state.
Input
Operation slack-INC-88-v1 timed out after upload. The operator wants to post it again immediately, but the first request may have reached the target channel.
Output
A blocked recovery plan that preserves the unknown attempt, searches by exact workspace, channel, actor, time, placement, and body fingerprint, branches for one, zero, multiple, and inconclusive matches, and never retries blindly.
Creator
Jjavrix
