All Articles
Stop the Bill Before It Balloons: Designing API Key Blast Radius for Unattended Pipelines
Designing for leaks instead of pretending they won't happen: workspace-scoped keys, zero-downtime rotation, and a usage watchdog that flags spikes with a rolling baseline and median absolute deviation — wired into a scheduled run.
When the Same Model Name Starts Behaving Differently: A Startup Canary for Unattended Pipelines
An in-place Opus upgrade can change your output, and an unattended publishing pipeline will never notice. Here is a lightweight startup canary that fingerprints behavior, catches drift, and halts the batch — with measured cost and latency.
We Collected Plenty of Claude Code Usage Data — Then Budgeting Still Didn't Work. Field Notes on Cost Attribution and Idle Seats
The Claude Code Analytics API gives you data, but data alone doesn't run a budget. Here are field notes on turning raw usage logs into cost attribution, idle-seat detection, and alerts that don't cry wolf — with working code and the thresholds we actually use.
Generating localized App Store listing metadata within character limits using the Claude API
Raw translations overflow App Store Connect's character limits. Generate per-locale listing metadata within them using Claude API structured output and a repair loop.
The Day a Non-Responding MCP Call Swallowed an Entire Unattended Run — Owning the Stop With Your Own Deadline
When a remote MCP tool call stops responding, an unattended scheduled run just keeps waiting. Instead of leaving the cutoff entirely to the platform, here is how I designed my own deadline and a per-connector circuit breaker to own the stop — with working code.
My Unattended Task Was Overwriting the Previous Day's Log — the Container's date Was Returning UTC
A Cowork scheduled task that wrote date-stamped logs was silently overwriting the prior day's file. The culprit was the container's date returning UTC. Here is how I isolated it and the permanent fix: pin the timezone, append instead of overwrite, and detect the failure.
Higher Rate Limits Don't Mean Tighter Schedules — Spend the Headroom on 429 Recovery
When Claude Code's rate limits went up, the instinct was to pack the schedule tighter. Here's why I did the opposite and routed the new headroom into retry budget instead — a pacing note for unattended pipelines.
Your Sandbox Can Run the Code but Shouldn't Read Your Credentials — Shrinking the Secret-Read Surface with sandbox.credentials
Claude Code's sandbox can still read ~/.aws/credentials and token env vars by default. Using sandbox.credentials (v2.1.187+), here is how I tightened the secret-read surface of unattended runs at the OS level, with config and verification you can reuse.
Reach a Remote MCP Server in a Single API Request: Implementing the Messages API MCP Connector
How to call a remote MCP server's tools using only the Messages API's mcp_servers and mcp_toolset—no local MCP client. Covers allowlist/denylist design, response handling, and the pitfalls to avoid before unattended production use.
When the Previous Run Hasn't Finished and the Next One Starts: Leases and Fencing Tokens for Scheduled Agents
A scheduled agent that runs on a fixed clock can overtake itself and start twice. From the moment a naive lock breaks to leases, fencing tokens, and bounded catch-up — worked through with the implementation I actually run.
When Your Support AI Is Confidently Wrong in Production — Notes on Refusing Outside Its Grounding and Routing to Humans
A field-tested approach to the Claude API support agent that demos perfectly yet states non-existent facts in production. Covers deciding 'don't answer' at retrieval time, grounded generation, measuring confident-wrong rate, and tuning escalation precision.
Productionizing a Claude Design Prototype — Single Source, CI, and OGP Auto-Generation
Turn a Claude Design prototype into something that survives production with Claude Code. The call to keep the generated runtime as your foundation, separating logic with a mixin, a single-source data design around a ledger CSV, and CI auto-updates with real-browser OGP capture — implementation included.