Show HN: Git-native-issue – issues stored as commits in refs/issues/

Show HN: AgentBudget – Real-time dollar budgets for AI agents

Show HN: AgentBudget – Real-time dollar budgets for AI agents Hey HN,<p>I built AgentBudget after an AI agent loop cost me $187 in 10 minutes — GPT-4o retrying a failed analysis over and over. Existing tools (LangSmith, Langfuse) track costs after execution but don&#x27;t prevent overspend.<p>AgentBudget is a Python SDK that gives each agent session a hard dollar budget with real-time enforcement. Integration is two lines:<p><pre><code> import agentbudget agentbudget.init(&quot;$5.00&quot;) </code></pre> It monkey-patches the OpenAI and Anthropic SDKs (same pattern as Sentry&#x2F;Datadog), so existing code works without changes. When the budget is hit, it raises BudgetExhausted before the next API call goes out.<p>How it works:<p>- Two-phase enforcement: estimates cost pre-call (input tokens + average completion), reconciles post-call with actual usage. Worst-case overshoot is bounded to one call. - Loop detection: sliding window over (tool_name, argument_hash, timestamp) tuples. Catches infinite retries even if budget remains. - Cost engine: pricing table for 50+ models across OpenAI, Anthropic, Google, Mistral, Cohere. Fuzzy matching for dated model variants. - Unified ledger: tracks both LLM calls and external tool costs (via track() or @track_tool decorator) in a single session.<p>Benchmarks: 3.5μs median overhead per enforcement check. Zero budget overshoot across all tested scenarios. Loop detection: 0 false positives on diverse workloads, catches pathological loops at exactly N+1 calls.<p>No infrastructure needed — it&#x27;s a library, not a platform. No Redis, no cloud services, no accounts.<p>I also wrote a whitepaper covering the architecture and integration with Coinbase&#x27;s x402 payment protocol (where agents make autonomous stablecoin payments): <a href="https:&#x2F;&#x2F;doi.org&#x2F;10.5281&#x2F;zenodo.18720464" rel="nofollow">https:&#x2F;&#x2F;doi.org&#x2F;10.5281&#x2F;zenodo.18720464</a><p>1,300+ PyPI installs in the first 4 days, all organic. Apache 2.0.<p>Happy to answer questions about the design.