Claude Fable 5 Plans, Credits, and 5.1 Migration Steps, Tests, and Rollback

Quick Answer

Claude Fable 5 is now a previous-generation record. Anthropic introduced Fable 5.1 on September 1, 2026 as the current generally available generation, including the first-party API ID claude-fable-5-1.

The July 20 Fable 5 plan rules still explain existing subscriptions, but they do not prove which generation appears in a live model picker or how a new 5.1 workload is billed. Use this split:

Surface or plan	Fable 5 record	Decision now
Claude Pro	July 20 guidance used usage credits from the start	Check the live model picker, current plan article, credits, and spend limit
Claude Max	July 20 guidance included limited Fable use inside shared weekly limits	Check which Fable generation is included and the current weekly-share rule
Team or Enterprise	July guidance differed by premium versus standard seat	Use the actual seat, admin policy, contract, and live model availability
Claude API	Historical ID claude-fable-5	Evaluate claude-fable-5-1; verify Models API, rate limits, effort default, and data controls
Token billing	Fable 5 base price was $10 input / $50 output per million tokens	Fable 5.1 keeps those base rates and prices cache reads at $0.25 per million tokens
AWS, Google Cloud, or Azure	Fable 5 used platform-specific catalogs	Anthropic lists Fable 5.1 on all three; verify platform ID, region, quota, contract, and routing
Enterprise data controls	Covered-model policy introduced a 30-day boundary for some ZDR arrangements	Check phased EFS eligibility, opt-in storage and review controls, plus transition ZDR
Flowith	Not established by Anthropic sources	Live Flowith model selector and entitlement

The earlier promotion is over. Anthropic’s July plan support article says the included promotion ended July 19, 2026 at 11:59:59 PM PT and the Fable 5 plan rules began July 20. Recheck the live article before treating those rules as current 5.1 entitlement.

Use the Claude Fable 5 model guide for the previous-generation entity record and migration checks. Use the Fable 5 vs Mythos 5 guide for the 5-to-5.1 safeguard and trusted-access boundary.

Source check: Anthropic’s Fable 5.1 and Mythos 5.1 launch and Enterprise Frontier Safeguards announcement were checked September 2, 2026. The Fable 5 plan rules below remain dated July 20 evidence; plan names, quotas, prices, rollout states, regions, and model availability can change.

What Changed With Fable 5.1

Anthropic says Fable 5.1 is the current generally available model across its products, Amazon Web Services, Google Cloud, and Microsoft Azure. Developers can start with claude-fable-5-1 on the Claude API.

The base token rates remain $10 per million input tokens and $50 per million output tokens, but the 5.1 cache-read rate is $0.25 per million tokens. Anthropic estimates about 25% lower cost than Fable 5 for typical token-billed workloads and up to about 45% for highly agentic, cache-heavy work. Those are provider estimates from its measured workload mix, not a promise for a particular application.

Before migrating, record:

• old and new model IDs;
• effort setting and product default;
• cache creation and cache-read mix;
• representative quality, latency, tool, and fallback tests;
• plan inclusion versus usage credits;
• cloud region, endpoint, quota, and contract;
• current retention or EFS arrangement;
• rollback criteria for an existing Fable 5 integration.

Why the Dates Look Confusing

Several accurate announcements describe different moments:

1. Anthropic launched Fable 5 on June 9.
2. Access was suspended after a June 12 export-control directive.
3. Anthropic announced global restoration beginning July 1.
4. The redeployment announcement described included access through July 7, then usage credits.
5. Anthropic later extended the promotion through July 19.
6. The current plan treatment began July 20.
7. Anthropic introduced Fable 5.1 as the current generation on September 1.

When a launch post and a later support article conflict on a time-bound promotion, use the latest live support and account evidence for today’s plan decision. Preserve the July rules as Fable 5 lifecycle history, not proof of current 5.1 inclusion.

July 20 Fable 5 Plan Record

Pro

Under the July 20 Fable 5 rules, access used pay-as-you-go usage credits from the start and did not draw from the Pro plan’s included usage limits. Recheck the live plan before applying that treatment to Fable 5.1.

Check:

• whether usage credits are enabled;
• the funded balance or payment method;
• per-session and monthly spend limits;
• the current standard API rates;
• whether the account received any separate one-time promotion.

Do not describe a temporary credit promotion as permanent plan inclusion.

Max

Under the July 20 record, Fable 5 was part of the Max plan’s shared weekly usage limit and up to 50% of that weekly limit could be used on Fable.

This is not 50% additional usage. Fable and other models draw from the same total weekly limit. After reaching the Fable share, the user can:

• switch to another model and continue within remaining plan limits; or
• continue with Fable through usage credits.

Team and Legacy Seat-Based Enterprise

The seat type matters:

• premium seats follow the included-limit treatment;
• standard seats use usage credits from the start.

Confirm the actual seat assignment and organization policy. A Team or Enterprise organization name alone does not reveal the entitlement.

For current enterprise contracts or newer consumption-based plans, use the admin console and governing agreement rather than extrapolating from the legacy seat article.

How Usage Credits Work

Usage credits are consumption-based billing that can continue a Claude session beyond included plan access or provide Fable access where it is not included.

Anthropic’s support documentation says credits:

• use standard API rates;
• can be enabled or disabled;
• support spend limits;
• are visible separately from included usage;
• apply across Claude conversations and Claude Code;
• do not change the regular usage-limit reset schedule.

Set a conservative spend limit before starting a long-context or agentic workload. Project files, tools, retries, and long outputs can increase token consumption.

How to Check Fable in Claude Products

Anthropic documents Fable 5 in:

• Claude on the web;
• Claude Desktop;
• Claude Mobile;
• Claude Code;
• Claude Cowork.

Open the current model picker and note the exact Fable generation rather than stopping at the family name. The historical Fable 5 support article required Claude Code 2.1.170 or later; a current 5.1 evaluation must use today’s product version and release notes.

If the model is missing, check:

1. product version;
2. signed-in account;
3. plan and seat type;
4. region or supported-country status;
5. organization administrator policy;
6. usage-credit setup;
7. current provider status.

Developer API Access and Migration

The previous first-party API model ID is:

claude-fable-5

Anthropic now documents the current model ID as:

claude-fable-5-1

The historical Fable 5 record includes:

• text and image input;
• text output;
• 1 million token context;
• up to 128,000 output tokens;
• adaptive thinking always on;
• $10 per million input tokens;
• $50 per million output tokens.

Fable 5.1 keeps those base token rates and adds a $0.25-per-million cache-read rate. Treat that as a 5.1 rate, not a retroactive change to every historical Fable 5 bill.

The dateless 5 ID is a pinned snapshot in Anthropic’s naming scheme, not an evergreen pointer to 5.1. Put model IDs in configuration, monitor lifecycle notices, and run a controlled migration instead of assuming the old ID moves automatically.

Before production use, verify:

• account access;
• regional availability;
• current limits and Models API record;
• rate limits and concurrency;
• prompt caching and Batch API pricing;
• output and tool behavior;
• covered-model retention;
• fallback and failure handling.

Cloud Platform Access

Anthropic says Fable 5.1 is available across Amazon Web Services, Google Cloud, and Microsoft Azure. That provider statement does not reveal whether one account, region, or contract is ready.

Cloud access can differ by:

• platform-specific model ID;
• global, multi-region, or regional endpoint;
• account allowlist;
• cloud region;
• quota;
• procurement contract;
• data routing;
• retention and logging controls.

Do not copy the first-party API ID blindly into a cloud request. Use the current cloud documentation and the organization’s enabled model catalog.

The EFS and Data-Retention Boundary

Fable 5 is a covered Mythos-class model, but the data-control decision changed materially after the original launch.

Anthropic announced Enterprise Frontier Safeguards as a phased system intended to combine zero-data-retention privacy with automated misuse detection. Eligible customers can use Fable 5 and Fable 5.1 with zero data retention until EFS is ready.

Where EFS is enabled, Anthropic says:

• activity data used for monitoring can stay in the customer’s own cloud account;
• the customer’s encryption keys, access policies, and audit logging can govern that storage;
• automated monitoring correlates signals across a rolling window and sends flags to the customer;
• no Anthropic human review is required; the customer’s authorized team can review flags;
• customer-owned storage, customer-managed keys, and automated review are separate opt-in controls;
• EFS does not change model behavior, API pricing, or rate limits;
• Anthropic does not charge for EFS, while the cloud provider can charge for storage, reads, writes, and egress.

This is not a universal promise that every Fable workload has zero retention today. Verify eligibility, rollout phase, covered product, storage location, review responsibility, cloud cost, and contract. Consumer data terms remain separate.

Flowith Is a Separate Availability Check

Anthropic’s global Fable release does not establish:

• a Flowith model mapping;
• a Flowith plan entitlement;
• Flowith pricing;
• context or output limits in Flowith;
• provider routing;
• data handling on a Flowith surface.

Check the current Flowith workspace and first-party Flowith documentation. If Fable is not listed, use an available model rather than treating the Anthropic ID as an input field.

Access Checklist

Before choosing a Fable generation, record:

• surface: Claude app, Code, API, cloud, or Flowith;
• current date and source;
• plan and seat;
• included limit versus usage credits;
• spend cap;
• old and target model ID plus platform ID;
• region and quota;
• context and output limits;
• safeguard fallback implications;
• transition ZDR or EFS eligibility, opt-ins, storage, review, and organization approval;
• fallback model and migration plan.

Frequently Asked Questions

Is Fable 5 free with a paid Claude plan?

Not universally. Under the July 20 Fable 5 rules, Max and premium Team or legacy Enterprise seats included limited Fable use inside their shared weekly limit, while Pro and standard seats used usage credits from the start. Check the live plan before applying that record to Fable 5.1.

Do usage credits add to my weekly limit?

They are separate consumption-based billing. They do not increase or reset the plan’s included weekly limit.

Can I turn usage credits off?

Anthropic says individual paid-plan users can disable usage credits in usage settings. Organization admins may have separate controls.

Is Fable 5 available through Claude Code?

The historical support article documented it subject to plan or credits and required Claude Code 2.1.170 or later. Use a current Claude Code version and verify whether the selector now offers Fable 5 or Fable 5.1 for the account.

Should I use Fable 5 or Fable 5.1 for a new API integration?

Evaluate Fable 5.1 first. Anthropic identifies claude-fable-5-1 as the current generally available API model. Keep Fable 5 only when compatibility testing, an existing production dependency, or a governing contract requires it.

Is Fable 5.1 always 25% cheaper than Fable 5?

No. Anthropic estimates about 25% lower cost for typical token-billed workloads because cache reads cost $0.25 per million tokens, with larger estimated savings for cache-heavy agentic work. Actual savings depend on token mix, cache reuse, effort, tools, retries, and platform billing.

Does EFS mean every enterprise gets zero data retention immediately?

No. EFS is rolling out in phases. Eligible Fable 5 and Fable 5.1 customers receive transition ZDR until EFS is ready, but the exact surface, opt-in controls, customer cloud storage, review ownership, and contract must be confirmed.

Official Sources

• Anthropic: Introducing Claude Fable 5.1 and Claude Mythos 5.1
• Anthropic: Enterprise Frontier Safeguards
• Anthropic: Claude Fable 5 and Claude Mythos 5
• Anthropic: Redeploying Claude Fable 5
• Claude Platform model overview
• Claude Fable 5 on your plan
• Manage usage credits for paid Claude plans
• Data retention practices for covered models