Two Anthropic Changes Hit Tomorrow: Old Claude 4 Models Retire, Agent SDK Billing Splits Off

Two separate Anthropic changes take effect on June 15, 2026. The first is straightforward: two old Claude 4 model IDs stop working. The second is more structural: programmatic usage via the Agent SDK and related tools moves off your subscription limit onto a separate credit pool.

Neither change affects interactive Claude.ai use or Claude Code running in a terminal. Both affect developers with API integrations or automated workflows.

Model retirements

The following API model IDs retire on June 15 at 9am PT:

Retiring model	Recommended replacement
claude-sonnet-4-20250514	claude-sonnet-4-6
claude-opus-4-20250514	claude-opus-4-8

After the deadline, API calls to either of those model IDs will return an error. There is no grace period. If your application hard-codes claude-sonnet-4-20250514 or claude-opus-4-20250514, it breaks.

The fix is a one-line string update in your config or API call. Anthropic has a migration guide covering the specifics. Consumer Claude.ai accounts and Claude Code’s managed environments route model selection automatically, so those are unaffected.

Agent SDK billing split

Starting June 15, the following usage types move off your normal subscription limit:

• Agent SDK (claude -p)
• Claude Code GitHub Actions
• Third-party Agent applications built on the Agent SDK

Each will draw from a new, separately billed credit pool. The amounts per plan:

Plan	Monthly agent credit
Pro	$20
Max 5x	$100
Max 20x	$200

Credits are metered at standard API list rates, are per-user (not pooled across a team), refresh monthly with your billing cycle, and do not roll over. Once you exhaust them, programmatic requests stop unless you have enabled usage credit overflow billing.

Interactive Claude Code sessions in your terminal, claude.ai chat, and Claude Cowork all remain on your existing subscription. Only the automated, programmatic path moves.

Anthropic framed this as matching billing to usage type: subscription pricing for interactive work, API-rate billing for programmatic load. If you run automated agents heavily, check whether the included credit covers your workload. The math depends on your typical token consumption.

What to do

For the API retirements: update any hard-coded model strings before tomorrow morning. Run a search for claude-sonnet-4-20250514 and claude-opus-4-20250514 in your codebase.

For the billing split: if you use claude -p, Claude Code GitHub Actions, or any third-party agent platform powered by the Agent SDK, verify whether your plan’s monthly credit covers your typical usage. If not, either reduce your automated usage, upgrade your plan, or enable overflow billing so requests don’t stop mid-run.

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Sources: Anthropic model deprecations page, Anthropic billing change announcement (archived), Codersera breakdown