Tool-specific setup, operation, troubleshooting and integrations
What this shelf holds
Setup, operation and troubleshooting for specific tools: Claude Code, Codex, the OpenAI API, and the open-source projects this site teaches with. Tool behavior changes, so each piece says what was checked and when.
Most of these are short. A note names one behavior, one check you can run and one limit. The longer guides take a tool from an empty terminal to a working result.
Picked by the editor
When cron or CI runs Codex, it starts wherever the scheduler started, so relative paths can point at the wrong project. Set the working directory in the command instead of inheriting it. You need: the Codex CLI, a terminal, and a project that is a Git…
When Codex ignores a rule in AGENTS.md, check which instruction files it loaded before you add another rule. A new rule can make the conflict harder to see. You need: the Codex CLI and a repository with at least one AGENTS.md. The command below runs Codex in…
Three hundred lines of instructions and it still breaks your conventions. So you add more rules. It gets worse. My working hypothesis is that a long instruction file may make important rules harder for the model to follow. First check that the file loaded and…
Anthropic measured it: users approve about 93% of permission prompts. A gate that opens 93% of the time is a doorbell. Here is what the permission system actually enforces, what it cannot, and the standing rules worth adopting before you delegate anything that matters.
Your lunch break has a token price. The model remembers nothing between turns, so every request re-sends the whole conversation — which means cost scales with context carried, not work requested. Here is the cost function, the dials that matter, and the ledger line worth keeping.
Clone it, install it editable, run the offline example, then read the 67-symbol API you'd actually build on. A working agent in about fifteen minutes, no API key required.
Courses and chapters
Newest on this shelf
A handoff should let someone resume the work without replaying every exploratory turn. Give them the state they need to make the next decision. Ask for the working directory, branch, source revision, changed files, checks run and remaining blockers. Include…
A generated file can look like the obvious place to fix a typo. The next build may overwrite that edit and bring the problem back. Ask Codex to trace the file to its generator or source collection before changing it. Require the report to name the build…
If you paste the same cleanup instructions every week, the reusable asset is the procedure and its examples, not the conversation history. Start with one narrow task such as checking the required columns in a synthetic expense file. Write a skill that names…
A command can print plausible output and still fail. Your next automation step should require successful completion and a valid artifact. For a Codex report job, capture the process status and validate the saved report before copying it to its destination…
Before applying a mechanical change across a repository, prove it on a file whose intended result you can inspect completely. Create an isolated worktree and choose a small example with one normal case and one exception. Ask Codex to make the migration, run…
A skill can look excellent on the example it was written for. A nearby request outside its scope reveals whether its boundary is clear. For a skill that validates a sales CSV, add one accepted fixture and one request to email the resulting report to…
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