GAP-MCPC-003: Channel Permission Relay (Breakpoint Approval via Channels)

Description

Route breakpoint approval prompts through messaging channels and accept approvals from channel responses. An operator on Slack can see a breakpoint notification and approve/reject without being at the terminal.

CC Implementation

CC's channel permission relay (src/services/mcp/channelPermissions.ts):

{request_id, behavior}

(documented and accepted risk -- see PR discussion in CC source)

• When a permission dialog appears, CC sends the prompt via active channels
• Races channel reply against local UI / bridge / hooks / classifier
• First resolver wins via claim() pattern
• Inbound approval: notifications/claude/channel/permission with
• Channel server must declare capabilities.experimental['claude/channel/permission']
• Security model: the approving party is the human via the channel, not Claude
• Risk assessment: a compromised channel server CAN fabricate approvals
• Feature-gated separately from channels: tengu_harbor_permissions

Current State

Breakpoints are approved only via: 1. CLI interaction (readline prompt) 2. Auto-approval rules (~/.a5c/breakpoint-approvals/rules.json) 3. Programmatic task:post from the harness operator

No external channel routing. Operator must be at the terminal or running the harness to approve breakpoints.

Target State

Breakpoint prompts routed to configured channels. Channel responses race against local interaction. First approval wins. Security: channel-based approval requires explicit opt-in per breakpoint tag/expert level. High-risk breakpoints can be configured to require terminal-only approval.

[Slack #orchestration]
babysitter-bot: Breakpoint in run 01KNKDVE...
  "Review gap audit results -- 52 removed, 25 reframed. Approve?"
  React: thumbsup to approve, thumbsdown to reject

[operator reacts thumbsup]

babysitter: Breakpoint approved via Slack by @tal (12s response time)

Dependencies

• GAP-MCPC-001 -- MCP channel connection
• GAP-BRK-002 -- breakpoint delegation to external systems

Key Files

Recommendation

Phase 3. High value for teams -- enables async approval workflows. Implement after MCP channel connection (GAP-MCPC-001) and breakpoint delegation (GAP-BRK-002). The claim() racing pattern from CC is elegant and should be adopted.