[Enhancement] Pre-limit usage alerts and webhooks — notify users before session/weekly budgets are exhausted

[daskuntal75]

Summary

Claude provides no warning before a usage limit is reached. Sessions stop when a budget is exhausted with no advance notice. There is no programmatic way to subscribe to limit events or throttle automation before hitting hard stops.

Use cases blocked

1. User mid-way through a long debugging session hits weekly limit unexpectedly — work lost, session state gone
2. Developer building on the API has no way to alert end users before rate limits degrade service
3. Automation tooling cannot self-throttle based on budget proximity

Proposed solution — two tiers

Tier 1 (UI only, low effort)

Email/push notification when session or weekly budget reaches a configurable threshold (default: 80%). Opt-in in account settings.

Tier 2 (API, higher effort)

Webhook or SSE endpoint firing on budget threshold events:

{
  "event": "budget_threshold",
  "limit_type": "weekly_all_models_budget",
  "threshold_pct": 80,
  "current_pct": 81,
  "resets_at": "2026-05-11T10:00:00Z"
}

Minimum viable version (lowest effort)

Add an X-Budget-Remaining-Pct response header to every API call:

X-Budget-Remaining-Pct-Session: 23
X-Budget-Remaining-Pct-Weekly: 41

This lets developers build their own alerts without requiring Anthropic to implement full webhook infrastructure.

Reference

https://github.com/daskuntal75/llm-cost-kit/blob/main/docs/anthropic-issues-submit-ready.md

[Jairooh]

Production AI systems need real-time budget visibility to avoid unexpected service disruptions. The use cases you've identified (automation throttling, user alerts before limits) are exactly why budget management is critical for reliability. If native API support takes time, AgentShield provides cost tracking per agent with budget alerts and auto-enforcement today — useagentshield.net/from/github