--- title: "Model allowlist, lock the team to the models you actually pay for | Recipe — StudioMeyer Academy" description: "Use availableModels to restrict which models a session can pick, and enforceAvailableModels in managed settings so project or user config can't widen it. Stops surprise Opus bills and keeps a team on an approved set." canonical: "https://studiomeyer.academy/en/recipes/11.6-model-allowlist" language: en markdown_versions: ["https://studiomeyer.academy/en/recipes/11.6-model-allowlist.md"] publisher: "StudioMeyer Academy, https://studiomeyer.academy (llms.txt: https://studiomeyer.academy/llms.txt)" --- [← Alle Recipes](https://studiomeyer.academy/recipes) Phase 11 · Operator Skills Library·6 steps # Model allowlist, lock the team to the models you actually pay for Use availableModels to restrict which models a session can pick, and enforceAvailableModels in managed settings so project or user config can't widen it. Stops surprise Opus bills and keeps a team on an approved set. 6 steps0% Du liest ohne Account. Mit [Login](https://studiomeyer.academy/login?next=/recipes/11.6-model-allowlist) speichern wir Step-Fortschritt + Notes. # Model allowlist By default any session can pick any model your plan exposes. For a solo driver that is fine. For a team, or for an unattended agent that runs on a schedule, it is a cost trap. One config that quietly defaults to Opus and your daily spend doubles without anyone noticing. The fix is the `availableModels` allowlist. You declare the exact set of model IDs a session is allowed to use, and everything outside that list disappears from the `/model` picker. As of June 2026 there is also `enforceAvailableModels`, a managed setting that closes the loophole where a project or user config could widen the list again. ### Step 1: Decide what the team is allowed to run Write down the models you actually want in play before you touch any config. A typical cost-aware set looks like this: - `claude-sonnet-5` for the daily driver, most work - `claude-haiku-4-5` for cheap, high-volume tasks - `claude-opus-5` only if you genuinely need it, and you accept the bill If you do not need Opus for a given seat or a given scheduled agent, leave it off the list entirely. The point of an allowlist is that the expensive option is not one fat-finger away. ### Step 2: Add availableModels to settings Edit `~/.claude/settings.json` (user scope) or `.claude/settings.json` (project scope) and add an `availableModels` array with the exact model IDs: ```json { "availableModels": [ "claude-sonnet-5", "claude-haiku-4-5" ] } ``` After this the allowlist is active everywhere a model can be named. The `/model` picker only shows Sonnet and Haiku, an off-list `--model` or `ANTHROPIC_MODEL` is rejected, subagents and skills inherit the list, and since v2.1.176 `/fast` refuses to toggle when that would switch to an off-list Opus. The one thing plain `availableModels` leaves alone is the Default option itself, which keeps resolving to the account default until you add `enforceAvailableModels` in Step 4. ### Step 3: Use version-specific IDs when you mean it If you pin a version-specific ID like `claude-opus-5`, the allowlist matches that exact entry. A June 2026 fix made sure version-specific IDs no longer accidentally hide the matching `/model` entries. So you can safely write the precise ID rather than a family alias when you want to pin a single version. This matters for reproducibility. An unattended agent that ran fine yesterday should not silently jump to a newer model after an update. Pin the exact ID and you know what runs. ### Step 4: Enforce it from managed settings User and project settings are easy to override. If you run a real team, put the allowlist in managed settings and turn on `enforceAvailableModels`: ```json { "availableModels": [ "claude-sonnet-5", "claude-haiku-4-5" ], "enforceAvailableModels": true } ``` With `enforceAvailableModels` enabled, the allowlist also constrains the Default model. A Default that would resolve to a disallowed model now falls back to the first allowed model. And critically, user or project settings can no longer widen a managed `availableModels` list. The team gets the set you approved and cannot quietly add Opus back. ### Step 5: Check it took effect Open a session in the scope you configured and run `/model`. You should see only the models on your list. Then check the aliases: with Opus off the list, `/fast` refuses an off-list switch with a message like "is not in your organization's allowed models", and an off-list `--model claude-opus-5` is rejected. The Default option keeps resolving to the account default until you turn on `enforceAvailableModels` in Step 4. If you used managed settings, try to override `availableModels` from a project `.claude/settings.json` and confirm it does not widen the list. If the managed enforcement is working, your local addition is ignored. ### Step 6: Wire it into your scheduled agents This is where the allowlist pays for itself. Any background or scheduled agent inherits the settings of its scope. Put a tight allowlist on the directory your unattended agents run in, drop Opus, and a runaway loop costs Haiku money instead of Opus money. Combine this with `/usage` to watch the per-model breakdown over the last 24 hours and you have a clean, boring cost floor. ## Source `availableModels`, `enforceAvailableModels`, the Default fallback behavior, and the version-specific ID fixes are documented in the official Claude Code changelog, June 2026: https://code.claude.com/docs/en/changelog [← CLAUDE.md management, automate](https://studiomeyer.academy/recipes/11.5-claude-md-management) [Dedicated agents, full MCP sco →](https://studiomeyer.academy/recipes/12.1-dedicated-agents) Phase 11 Production rituals: sm-deploy, ssh-batch, email-safe-test, prisma-safety [Alle Phasen →](https://studiomeyer.academy/recipes) ## Sitemap Public pages of this site as Markdown: [sitemap](https://studiomeyer.academy/sitemap.md). Curated entry point: [llms.txt](https://studiomeyer.academy/llms.txt), full text: [llms-full.txt](https://studiomeyer.academy/llms-full.txt).