Can I use Claude Fable 5 with the Claude API?

Yes. Claude Fable 5 is available through the Anthropic API. It supports streaming, tool use, prompt caching, vision, the Batch API, and MCP server integration.

When should I use Fable 5 vs Sonnet for content production?

For most content production, Sonnet 4.6 is the right call at 3.3× less cost. Reach for Fable 5 when you need to synthesize across a very large corpus, when the content requires deep domain reasoning with extended thinking, or when the task involves both large-context ingestion and complex output generation in a single pass.

Is Claude Fable 5 available in Claude.ai?

Fable 5 is available in Claude.ai on the Pro and Team plans, selectable from the model picker. For production-scale usage, the API with Batch API discounts is more economical.

What is the best way to reduce Claude Fable 5 API costs?

Three levers: model routing (only use Fable 5 when needed), prompt caching (cache reads cost $1.00/M vs $10.00/M), and Batch API (50% discount on non-real-time workloads). Stacking all three can reduce effective costs by 85–95%.

Tag: Claude API

Claude Skills vs MCP vs Connectors vs Plugins (2026)

Last verified: June 13, 2026

The simplest way to keep these straight: Skills teach Claude how to do a task, MCP servers and Connectors give Claude access to external systems, Plugins bundle several of these together, and Hooks and slash commands control a Claude Code session. A Skill is a folder of instructions Claude reads when relevant. MCP (the Model Context Protocol) is an open standard that connects Claude to your tools and data. A Connector is Anthropic’s packaging of a remote MCP server inside the Claude apps. A Plugin packages any combination of commands, agents, MCP servers, hooks, and skills for Claude Code. Every definition below is taken verbatim from Anthropic’s official documentation, fetched on the verification date.

The one-glance comparison

Four comparison cards for Claude skills, MCP, connectors, and plugins — One-glance comparison of the four extension surfaces.

This is the liftable summary. Each row is one mechanism; the third column is the distinction people most often get wrong — whether the thing teaches Claude how to do something or gives Claude access to something.

Type	What it is	Teaches-HOW or gives-ACCESS	Where it runs	How you install / enable it
Skill	A modular capability that packages instructions, metadata, and optional resources (scripts, templates) in a `SKILL.md` file that Claude uses automatically when relevant.	Teaches HOW. Provides domain-specific expertise: workflows, context, and best practices (procedural knowledge).	In Claude’s code execution environment / VM, where Claude has filesystem access, bash, and code execution.	claude.ai: upload a zip under Settings > Features. API: upload via the Skills API (`/v1/skills`) with the required beta headers (`code-execution-2025-08-25`, `skills-2025-10-02`, `files-api-2025-04-14`). Claude Code: a `SKILL.md` directory under `~/.claude/skills/` or `.claude/skills/`.
MCP server	An implementation of the Model Context Protocol — “an open-source standard for connecting AI applications to external systems.” Described as “a USB-C port for AI applications.”	Gives ACCESS. Connects Claude to data sources, tools, and workflows so it can access information and perform tasks.	Local (stdio) servers run as processes on your machine; remote servers run over HTTP (recommended) or SSE (deprecated).	In Claude Code: `claude mcp add`, at local, project, or user scope. Also configurable in `.mcp.json` or imported from Claude Desktop / claude.ai.
Connector	A feature that “let[s] Claude access your apps and services, retrieve your data, and take actions within connected services.” Custom connectors use remote MCP.	Gives ACCESS. Same access role as MCP — a Connector is the in-app packaging of a remote MCP server.	Custom connectors are reached from Anthropic’s cloud infrastructure, not from your local machine.	In the Claude apps under Customize > Connectors (or the in-chat “+” menu). Add a directory connector, or “Add custom connector” by URL.
Plugin	“A lightweight way to package and share any combination of” Claude Code customizations.	Both — it’s a container. Bundles things that teach HOW (commands, skills) and things that give ACCESS (MCP servers), plus hooks and subagents.	In Claude Code — “they’ll work across your terminal and VS Code.”	The `/plugin` command (public beta). For a marketplace: `/plugin marketplace add user-or-org/repo-name`, then install from the `/plugin` menu.
Hook	“User-defined shell commands, HTTP endpoints, or LLM prompts that execute automatically at specific points in Claude Code’s lifecycle.”	Controls behavior. Provides deterministic control rather than relying on the LLM to decide.	In Claude Code, firing at lifecycle events (e.g. `PreToolUse`, `PostToolUse`, `UserPromptSubmit`, `SessionStart`, `Stop`).	Configured in JSON settings files such as `~/.claude/settings.json` or `.claude/settings.json`, or bundled in a plugin.
Slash command	A command starting with `/` that controls a Claude Code session. Includes built-ins (e.g. `/help`, `/compact`) and custom commands.	Teaches HOW (custom) / controls session (built-in). Custom commands have been merged into Skills.	In the Claude Code session (terminal or VS Code).	Built-ins ship with Claude Code. Custom: a Markdown file under `.claude/commands/` (project) or `~/.claude/commands/` (personal); a `.claude/skills/<name>/SKILL.md` does the same.

Skills: teaching Claude a procedure

Side-by-side cards defining what Claude Code is and is not — Skills: teaching Claude a procedure.

An Agent Skill is “a directory containing a SKILL.md file” with YAML frontmatter plus instructions, and optionally additional markdown files, executable scripts, and reference resources. The point is procedural knowledge — it turns “general-purpose agents into specialists” by giving Claude the workflows and best practices for a task, the way you’d write an onboarding guide for a new teammate. Anthropic ships pre-built Skills for PowerPoint, Excel, Word, and PDF, and you can author your own.

What makes Skills cheap to install in bulk is progressive disclosure: Claude loads information in stages instead of all at once. The numbers below come straight from Anthropic’s Skills overview.

Loading level	When loaded	Token cost (per Anthropic docs)	Content
Level 1: Metadata	Always, at startup	~100 tokens per Skill	`name` and `description` from the YAML frontmatter
Level 2: Instructions	When the Skill is triggered	Under 5k tokens	The `SKILL.md` body — workflows and guidance
Level 3+: Resources	As needed	Effectively unlimited	Bundled files read or executed via bash without loading their contents into context

The name field is capped at 64 characters (lowercase letters, numbers, hyphens; it cannot contain the reserved words “anthropic” or “claude”), and the description is capped at 1,024 characters. One important constraint: custom Skills do not sync across surfaces — a Skill uploaded to claude.ai is not automatically available via the API, and Claude Code Skills are filesystem-based and separate from both.

MCP: the open standard for access

Flow from app/IDE through MCP to servers and data APIs — MCP: the open standard for access.

The Model Context Protocol is, in Anthropic’s words, “an open-source standard for connecting AI applications to external systems.” The canonical analogy: “Think of MCP like a USB-C port for AI applications. Just as USB-C provides a standardized way to connect electronic devices, MCP provides a standardized way to connect AI applications to external systems.” Using MCP, “AI applications like Claude or ChatGPT can connect to data sources (e.g. local files, databases), tools (e.g. search engines, calculators) and workflows (e.g. specialized prompts).”

An MCP server can expose three kinds of building block — tools, resources, and prompts. In Claude Code, resources are referenced with @server:protocol://resource/path and prompts surface as commands in the form /mcp__servername__promptname. You connect a server with claude mcp add, choosing a transport and a scope:

Scope	Loads in	Shared with team	Stored in
Local (default)	Current project only	No	`~/.claude.json`
Project	Current project only	Yes, via version control	`.mcp.json` in project root
User	All your projects	No	`~/.claude.json`

For transports, HTTP is “the recommended option for connecting to remote MCP servers,” local stdio servers “run as local processes on your machine,” and SSE is explicitly marked deprecated in favor of HTTP.

Connectors: MCP, packaged for the apps

A Connector is how the Claude apps surface MCP. Per Anthropic’s help center, “Connectors let Claude access your apps and services, retrieve your data, and take actions within connected services,” and “Custom connectors using remote MCP are available on Claude, Cowork, and Claude Desktop.” So a Connector is not a different technology from MCP — a custom connector is a remote MCP server wired into the Claude UI.

The most consequential detail is where the connection originates: “Custom connectors (remote MCP servers) are reached from Anthropic’s cloud infrastructure, not from your local machine.” That means a custom-connector MCP server must be reachable over the public internet — one hosted only on a private network, behind a VPN, or blocked by a firewall will not connect even if you can reach it yourself.

Aspect	Directory (pre-built) connector	Custom connector
Source	Pre-built integrations in the Connectors Directory	Added by you via a remote MCP server URL
Plan availability	Available across Claude plans	Free, Pro, Max, Team, and Enterprise
Free-plan limit	Per directory	“Free users are limited to one custom connector.”
Where to add it	Customize > Connectors, or the in-chat “+” > Connectors > Manage connectors

Plugins: a bundle, not a single thing

A Plugin is “a lightweight way to package and share any combination of” Claude Code customizations. The official announcement lists four bundle components, and the Claude Code documentation adds skills as a fifth thing a plugin can carry:

Component	What it adds
Slash commands	Custom shortcuts for frequently-used operations
Subagents	Purpose-built agents for specialized development tasks
MCP servers	Connections to tools and data sources through MCP
Hooks	Customizations of Claude Code’s behavior at key workflow points
Skills	Per the Claude Code docs, a plugin can include a `skills/` directory; plugin skills use a `plugin-name:skill-name` namespace

You install a plugin “directly within Claude Code using the /plugin command.” To pull from a marketplace — “curated collections where other developers can discover and install plugins” — you run /plugin marketplace add user-or-org/repo-name and then install from the /plugin menu. Plugins “work across your terminal and VS Code.” Plugins were announced on October 9, 2025, as a public beta for all Claude Code users.

Hooks and slash commands: controlling the session

The last two mechanisms aren’t about adding capability — they’re about controlling a Claude Code session. Hooks are “user-defined shell commands, HTTP endpoints, or LLM prompts that execute automatically at specific points in Claude Code’s lifecycle.” Their defining property is determinism: they provide deterministic control rather than relying on the LLM to make decisions. A PreToolUse hook can, for example, block a destructive rm -rf command regardless of what Claude intended. Hooks are configured in JSON settings files (such as ~/.claude/settings.json or a project’s .claude/settings.json) and fire at events including SessionStart, UserPromptSubmit, PreToolUse, PostToolUse, and Stop.

Slash commands start with / and control the session. Built-in commands like /help and /compact ship with Claude Code. Custom commands are Markdown files — a project command lives at .claude/commands/<name>.md and a personal one at ~/.claude/commands/<name>.md, with the file name becoming the command. As of the 2026 Claude Code docs, custom commands have been merged into Skills: a file at .claude/commands/deploy.md and a skill at .claude/skills/deploy/SKILL.md “both create /deploy and work the same way,” and existing .claude/commands/ files keep working.

Is a Connector the same as an MCP server?

Effectively yes, for custom connectors. Anthropic states “Custom connectors using remote MCP are available on Claude, Cowork, and Claude Desktop,” and that they “are reached from Anthropic’s cloud infrastructure.” A Connector is the Claude-app packaging of a remote MCP server; MCP is the underlying open standard.

What’s the difference between a Skill and an MCP server?

A Skill teaches Claude how to do a task — it “provide[s] Claude with domain-specific expertise: workflows, context, and best practices.” An MCP server gives Claude access to external systems — it connects Claude “to data sources, tools and workflows.” One is procedural knowledge; the other is a connection.

Do Skills cost a lot of context tokens?

Not until used. Per Anthropic’s docs, Level 1 metadata costs about 100 tokens per Skill and is always loaded; the full SKILL.md body (under 5k tokens) only loads when the Skill is triggered; and bundled resources are read on demand with effectively no upfront cost. This is the “progressive disclosure” design.

What can a Claude Code plugin contain?

“Any combination of” slash commands, subagents, MCP servers, and hooks, per the announcement; the Claude Code documentation adds that a plugin can also bundle a skills/ directory. You install one with the /plugin command, optionally from a marketplace added via /plugin marketplace add.

Are custom slash commands still a thing?

They still work, but they’ve been folded into Skills. The Claude Code docs state custom commands “have been merged into skills,” that existing .claude/commands/ files keep working, and that a command file and an equivalent SKILL.md both produce the same / command. Skills add optional extras like supporting files and automatic invocation.

Related on Tygart Media: what is MCP · Claude MCP guide.

June 13, 2026

Migrating Off Retired Claude Models: The Breaking-Chang (2026)

Last verified: June 13, 2026

Claude Opus 4 (claude-opus-4-20250514) and Claude Sonnet 4 (claude-sonnet-4-20250514) are deprecated and retire on June 15, 2026, after which requests to them return a 404. The official replacements are claude-opus-4-8 and claude-sonnet-4-6. But swapping the model string alone will break a working integration: depending on which target you choose, several request parameters that were valid on the May 2025 models now return a 400 error, and two changes alter behavior silently. This page maps each removed or changed parameter to the exact failure and the fix.

One distinction governs the whole migration. The Opus path (to claude-opus-4-8) is the strict one: it removes temperature/top_p/top_k and manual thinking budgets entirely. The Sonnet path (to claude-sonnet-4-6) is gentler: it keeps sampling parameters (with the older “one of temperature or top_p, not both” rule) and still accepts budget_tokens as deprecated-but-functional. The one rule both paths share: assistant-turn prefills now return 400.

The breaking-change matrix

Side-by-side panels contrasting old model IDs still in code with a migrate checklist — The breaking-change matrix.

Each row is a change that breaks on at least one migration target. “Error” means the API rejects the request server-side (HTTP 400) even though the SDK request type still type-checks. “Silent” means no error — the behavior simply differs.

Change	On Opus 4.8	On Sonnet 4.6	Symptom	Fix
`thinking: {type:"enabled", budget_tokens:N}`	400 error (removed)	Deprecated, still works	400 on Opus; cost/latency drift on Sonnet	`thinking: {type:"adaptive"}` + `output_config.effort`
`temperature` / `top_p` / `top_k`	400 error (removed)	Keep only one of `temperature` or `top_p`	400 on Opus if any set; 400 on Sonnet if both set	Remove on Opus; steer via prompt. Keep one on Sonnet
Assistant-turn prefill (last message `role:"assistant"`)	400 error	400 error	Request rejected on both	`output_config.format` (structured outputs) or system-prompt instruction
`thinking.display` default	Defaults to `"omitted"`	Returns summarized text	Reasoning text empty on Opus (silent)	Set `display: "summarized"` on Opus
Tokenizer	New tokenizer (more tokens)	Unchanged tokenizer	Same text counts higher on Opus; `max_tokens` too tight	Re-baseline with `count_tokens`; add headroom
`output_format` (top-level)	Deprecated API-wide	Deprecated API-wide	Works, but slated for removal	Move to `output_config: {format: {...}}`

Model ID swaps and retirement dates

Flow from Family to Seat to Generation to API id — Model ID swaps and retirement dates.

Retiring model	Model ID	Retires	Replacement
Claude Opus 4	`claude-opus-4-20250514` (alias `claude-opus-4-0`)	June 15, 2026	`claude-opus-4-8`
Claude Sonnet 4	`claude-sonnet-4-20250514` (alias `claude-sonnet-4-0`)	June 15, 2026	`claude-sonnet-4-6`

These are the original May 2025 models, not the later Opus 4.6 or Sonnet 4.5 releases. Use the exact replacement strings above — do not append a date suffix to claude-opus-4-8 or claude-sonnet-4-6 (they are dateless pinned snapshots).

budget_tokens to adaptive thinking

The Opus path removes the fixed thinking budget. thinking: {type:"enabled", budget_tokens:N} returns a 400 on claude-opus-4-8. The replacement is adaptive thinking — the model decides how much to think per request — with overall depth controlled by the effort parameter (low | medium | high | xhigh | max). There is no direct token-count equivalent; effort is an output-level control, not a thinking budget.

# Before (Claude Opus 4 / Sonnet 4)
client.messages.create(
    model="claude-opus-4-20250514",
    max_tokens=16000,
    thinking={"type": "enabled", "budget_tokens": 10000},
    messages=[{"role": "user", "content": "..."}],
)

# After (Claude Opus 4.8)
client.messages.create(
    model="claude-opus-4-8",
    max_tokens=16000,
    thinking={"type": "adaptive"},
    output_config={"effort": "high"},  # or "max", "xhigh", "medium", "low"
    messages=[{"role": "user", "content": "..."}],
)

On the Sonnet path, budget_tokens is deprecated but still functional on claude-sonnet-4-6, so it will not 400 — but you should still migrate to adaptive thinking. Note also that Sonnet 4.6 defaults to effort: "high" where Sonnet 4 had no effort parameter at all; if you do not set it explicitly you may see higher latency and token use after the swap.

Sampling parameters: removed vs. restricted

Desk with laptop, checklist notebook, and billing card ready before creating an Anthropic API key — Sampling parameters — removed vs restricted.

This is where the two paths diverge most. On claude-opus-4-8, setting temperature, top_p, or top_k to any non-default value returns a 400. Remove them entirely and steer behavior through prompting instead. (If you used temperature=0 for determinism, note it never guaranteed identical outputs on prior models either.)

# Opus path — sampling params 400 on claude-opus-4-8
# Before
client.messages.create(
    model="claude-opus-4-20250514",
    temperature=0.7,
    top_p=0.9,
    messages=[...],
)

# After — remove them
client.messages.create(
    model="claude-opus-4-8",
    messages=[...],
)

On claude-sonnet-4-6 the older Claude 4.x rule still applies: you may pass one of temperature or top_p, but passing both returns a 400. So a Sonnet 4 to Sonnet 4.6 move only requires dropping one of the two if you were setting both.

Assistant-turn prefills to structured outputs

Prefilling the final assistant turn — ending your messages array with a role: "assistant" message to force a response shape — returns a 400 on both claude-opus-4-8 and claude-sonnet-4-6. This is the one breaking change you cannot dodge by choosing the gentler target. The replacement depends on what the prefill was doing.

Prefill was used for	Replacement
Forcing JSON / YAML / schema output	`output_config.format` with a `json_schema`
Forcing a classification label	A tool with an `enum` field, or structured outputs
Skipping preambles (“Here is…”)	System-prompt instruction: respond directly, no preamble
Continuing an interrupted response	Move continuation into the user turn
Steering around bad refusals	Usually unnecessary now — plain user-turn prompting suffices

# Before (fails on both targets) — prefill forcing JSON shape
messages=[
    {"role": "user", "content": "Extract the name."},
    {"role": "assistant", "content": "{\"name\": \""},
]

# After — structured outputs replace the prefill
client.messages.create(
    model="claude-opus-4-8",
    max_tokens=1024,
    output_config={"format": {"type": "json_schema", "schema": SCHEMA}},
    messages=[{"role": "user", "content": "Extract the name."}],
)

Thinking display: the silent one

On claude-opus-4-8, thinking blocks still stream, but their thinking text field is empty unless you opt in — the default is display: "omitted". There is no error; if your UI rendered the summarized reasoning, it now shows a long pause before output. Restore it by setting the display mode:

thinking = {
    "type": "adaptive",
    "display": "summarized",  # default is "omitted" on Opus 4.8/4.7
}

The block-field name is unchanged — it is still block.thinking on a thinking-type block. The fix is the request parameter, not the response-handling code. (Sonnet 4.6 is not affected by this default change.)

The new tokenizer: re-baseline max_tokens

This change is Opus-only and easy to miss because it produces no error. claude-opus-4-8 uses the tokenizer introduced with Opus 4.7, under which the same text tokenizes to roughly 1x–1.35x as many tokens — up to about 35% more, around 30% on typical content, varying by workload. Three consequences:

What to check	Why
`max_tokens` ceilings and compaction triggers	The same output now consumes more tokens; tight limits truncate mid-thought
Client-side token estimators (e.g. fixed char-to-token ratios)	Calibrated against the old tokenizer; now undercount
Cost and rate-limit dashboards	`count_tokens` returns higher numbers; re-baseline before reacting

Re-run client.messages.count_tokens(model="claude-opus-4-8", ...) on a representative sample of your prompts. Do not apply a blanket multiplier. Sonnet 4.6 keeps the older tokenizer, so a Sonnet 4 to Sonnet 4.6 move has no tokenizer re-baseline to do.

The full checklist

Step	Opus 4 to 4.8	Sonnet 4 to 4.6
Update model ID string	Required	Required
Replace `budget_tokens` with adaptive thinking	Required (400)	Recommended (deprecated)
Sampling params	Remove all (400)	Keep only one (both 400)
Remove assistant-turn prefills	Required (400)	Required (400)
Set `display: "summarized"` if showing reasoning	Required for visible thinking	Not applicable
Re-baseline `max_tokens` for new tokenizer	Required	Not applicable
Set `effort` explicitly	Defaults to `high`	Defaults to `high`
Move `output_format` to `output_config.format`	Recommended	Recommended
Verify tool inputs parsed with a JSON parser	Recommended	Recommended
Spot-check one request, then roll out	Required	Required

If you run Claude Code, /claude-api migrate applies the model swap, breaking-parameter changes, prefill replacement, and effort calibration across a codebase, then produces a verify-it-yourself checklist. It asks you to confirm scope before editing any files.

Is migrating off Claude Opus 4 really not just a model-string change?

No. Moving to claude-opus-4-8 also requires removing temperature/top_p/top_k and any budget_tokens (all now return 400), removing assistant-turn prefills (400), opting back into summarized thinking if your UI shows it, and re-baselining max_tokens for the new tokenizer. Only the Sonnet 4 to Sonnet 4.6 move is close to a drop-in — and even that requires removing prefills.

When exactly do Claude Opus 4 and Sonnet 4 stop working?

June 15, 2026. After that date, requests to claude-opus-4-20250514 and claude-sonnet-4-20250514 return a 404. These are the original May 2025 models, not Opus 4.6 or Sonnet 4.5.

What replaces budget_tokens now that it errors on Opus?

Adaptive thinking (thinking: {type:"adaptive"}) plus the effort parameter inside output_config. There is no exact token-count equivalent: the model decides how much to think per request, and effort (low through max) tunes overall depth and spend. On Sonnet 4.6, budget_tokens still works but is deprecated.

Why does the same prompt cost more tokens on Opus 4.8?

Opus 4.8 uses the tokenizer introduced with Opus 4.7, under which the same text produces roughly 1x–1.35x as many tokens (about 30% more on typical content, up to ~35%). Re-run the count_tokens endpoint against claude-opus-4-8 and give max_tokens and compaction triggers extra headroom. Sonnet 4.6 keeps the older tokenizer, so it is unaffected.

My thinking summaries disappeared after migrating to Opus — is that a bug?

No. On Opus 4.8 (and 4.7), thinking.display defaults to "omitted", so thinking blocks stream with an empty text field. Set display: "summarized" in your thinking config to restore visible reasoning. The field name is unchanged; only the default flipped.

Related on Tygart Media: Claude Fable 5 guide · API quickstart.

June 13, 2026

Claude Code Billing & Monthly Credit Pools (2026)

Last verified: June 13, 2026

Claude Code has two billing models, and which one applies depends on how you run it, not just which plan you hold. When you use Claude Code interactively in the terminal or IDE on a Pro or Max plan, it draws from the same subscription usage limits as your Claude.ai chats. But starting June 15, 2026, Anthropic separates out programmatic usage: the Claude Agent SDK, the claude -p headless command, the Claude Code GitHub Actions integration, and third-party apps that authenticate through the Agent SDK will no longer count against your interactive subscription pool. Instead they draw from a new, separate monthly Agent SDK credit, billed at standard API rates. This page documents both models, the exact credit amounts per plan, and the SDK package rename you may also need to handle.

The two billing models at a glance

Workshop fuel gauge and metal tokens pouring into an API hopper, metaphor for pay-per-token pricing — Two billing models at a glance — no sticky dollar stickers.

The dividing line is interactive vs. programmatic. One number to remember: setting an ANTHROPIC_API_KEY environment variable overrides your subscription entirely — Claude Code then authenticates with that key and bills as pay-as-you-go API usage, regardless of plan.

Usage type	How it runs	Billed against
Interactive Claude Code	Terminal or IDE, human at the keyboard	Pro/Max subscription usage limits
Claude.ai chat	Web, desktop, mobile	Pro/Max subscription usage limits
Agent SDK (Python/TypeScript)	Your own programmatic projects	Separate Agent SDK credit (from June 15, 2026)
`claude -p` (non-interactive)	Headless / scripted Claude Code	Separate Agent SDK credit (from June 15, 2026)
Claude Code GitHub Actions	CI/CD automation	Separate Agent SDK credit (from June 15, 2026)
Any usage with `ANTHROPIC_API_KEY` set	API-key auth instead of subscription	Standard API rates (pay-as-you-go)

What changes on June 15, 2026

Per Anthropic’s support documentation: “Starting June 15, 2026, Claude Agent SDK and claude -p usage no longer counts toward your Claude plan’s usage limits.” Each subscription tier instead receives a fixed monthly Agent SDK credit. When that credit runs out, additional Agent SDK usage flows to usage credits at standard API rates — but only if you have enabled usage credits. If you have not, “Agent SDK requests stop until your credit refreshes.” Unused credits do not roll over to the next billing cycle, and there is no automatic fallback to the interactive pool.

Plan	Monthly Agent SDK credit
Pro	$20
Max 5x	$100
Max 20x	$200
Team (Standard seats)	$20
Team (Premium seats)	$100
Enterprise (seat-based Premium)	$200

What stays on the interactive subscription pool, unchanged: Claude conversations on web, desktop, and mobile; and interactive Claude Code in the terminal or IDE. The change is scoped strictly to programmatic execution.

How each pool is metered and priced

Infographic with three panels: protect the service, fair share, and cost control explaining rate limits — How each pool is metered.

Claude Code “charges by API token consumption” — the underlying meter is input/output tokens, including thinking tokens billed as output. On a subscription, that token consumption is what counts against your plan limits (interactive) or your Agent SDK credit (programmatic). The Agent SDK credit and any overflow are billed at standard API list rates; the per-model API token prices below are the verified current rates.

Pool	Meter	Price basis
Interactive (Pro/Max)	Tokens, against plan usage limits	Included in subscription
Agent SDK credit	Tokens, against monthly credit	Standard API rates
Overflow past the credit	Tokens, usage credits	Standard API rates (only if usage credits enabled)
API key (`ANTHROPIC_API_KEY`)	Tokens, pay-as-you-go	Standard API rates

Verified current API token prices (per million tokens) for models commonly used in Claude Code:

Model	Model ID	Input $/Mtok	Output $/Mtok
Claude Opus 4.8	`claude-opus-4-8`	$5.00	$25.00
Claude Sonnet 4.6	`claude-sonnet-4-6`	$3.00	$15.00
Claude Haiku 4.5	`claude-haiku-4-5`	$1.00	$5.00

Subscription plan prices

These are the published Claude plan prices the Agent SDK credits attach to. The Max 5x plan starts at $100/month; the $200 figure for Max 20x is documented as the matching Agent SDK credit amount for that tier.

Plan	Price
Free	$0
Pro	$20/month, or $17/month billed annually ($200 up front)
Max 5x	From $100/month
Team (Standard seat)	$25/seat/month, or $20/seat/month billed annually

The SDK rename: claude-code-sdk to claude-agent-sdk

Separate from billing, the SDK itself was renamed. Anthropic’s migration guide states: “The Claude Code SDK has been renamed to the Claude Agent SDK.” If you have code on the old package, you must update the package name, imports, and one Python type. The headless CLI command name is unchanged — it is still claude -p.

Aspect	Old	New
npm package (TS/JS)	`@anthropic-ai/claude-code`	`@anthropic-ai/claude-agent-sdk`
Python package	`claude-code-sdk`	`claude-agent-sdk`
Python options type	`ClaudeCodeOptions`	`ClaudeAgentOptions`
Default system prompt	Claude Code’s preset	Minimal (opt back in via `preset: "claude_code"`)

# TypeScript
npm uninstall @anthropic-ai/claude-code
npm install @anthropic-ai/claude-agent-sdk

# Python
pip uninstall claude-code-sdk
pip install claude-agent-sdk

Decision: which billing path applies to your work

Three cards for fast volume, daily workhorse, and deep flagship Claude seats — Which billing path applies to your work.

If you are…	Billing path
A developer coding interactively in the terminal	Subscription usage limits (unchanged)
Running `claude -p` in a script or cron job	Agent SDK credit (from June 15, 2026)
Running Claude Code in GitHub Actions	Agent SDK credit (from June 15, 2026)
Building an app on the Agent SDK with subscription auth	Agent SDK credit (from June 15, 2026)
A team or service account wanting budgets + usage reports	Set `ANTHROPIC_API_KEY` → standard API billing

Does interactive Claude Code billing change on June 15, 2026?

No. Anthropic’s documentation confirms interactive Claude Code in the terminal or IDE, and Claude conversations on web, desktop, and mobile, continue using subscription usage limits as before. Only programmatic usage — the Agent SDK, claude -p, GitHub Actions, and third-party Agent SDK apps — moves to the separate Agent SDK credit.

How much is the separate Agent SDK credit?

$20/month on Pro, $100 on Max 5x, $200 on Max 20x, $20 on Team Standard seats, $100 on Team Premium seats, and $200 on Enterprise seat-based Premium. The credit is billed at standard API rates, does not roll over, and refreshes monthly.

What happens when the Agent SDK credit runs out?

Additional Agent SDK usage flows to usage credits at standard API rates — but only if you have enabled usage credits. If you have not enabled them, Agent SDK requests stop until your credit refreshes. There is no automatic fallback to your interactive subscription pool.

How do I avoid the credit pool entirely?

Set an ANTHROPIC_API_KEY environment variable. Claude Code and the Agent SDK then authenticate with that key and bill as standard pay-as-you-go API usage, separate from any subscription. This is Anthropic’s recommended path for apps, CI jobs, service accounts, and team-owned projects that need budgets and usage reporting.

Was the Claude Code SDK renamed?

Yes. It is now the Claude Agent SDK. The npm package @anthropic-ai/claude-code became @anthropic-ai/claude-agent-sdk, the Python package claude-code-sdk became claude-agent-sdk, and the Python type ClaudeCodeOptions became ClaudeAgentOptions. The claude -p CLI command name is unchanged.

Related on Tygart Media: Claude Code getting started · Claude pricing · Pro vs Max.

June 13, 2026

Latest Claude Models — June 2026 (Current Lineup, Prici (2026)

Updated June 12, 2026. Fable 5 is the current top-tier model, released June 9, 2026. The full lineup: Fable 5 → Opus 4.8 → Sonnet 5 → Haiku 4.5. Pricing and availability verified against Anthropic’s official docs.

Direct Answer (August 2026): The latest available Anthropic Claude models are Claude Sonnet 4.6, Claude Opus 4.8, Claude Haiku 4.5, and Claude Fable 5. All models support 200k–1M context windows, vision multimodal inputs, structured tool calling (MCP), and server-side prompt caching.

Current Claude Models — Quick Reference

Three-column board mapping Claude model seats to flagship thinking, production workhorse, and fast volume jobs — Current Claude models — quick reference by job.

Model	API ID	Input $/MTok	Output $/MTok	Context	Best For
Claude Fable 5 🆕	`claude-fable-5`	$10.00	$50.00	1M tokens	Complex engineering, long-horizon agentic work
Claude Opus 4.8	`claude-opus-4-8`	$5.00	$25.00	1M tokens	Everyday advanced work, high-volume pipelines
Claude Sonnet 5	`claude-sonnet-5`	$3.00	$15.00	1M tokens	Balanced capability and speed
Claude Haiku 4.5	`claude-haiku-4-5-20251001`	$1.00	$5.00	200K tokens	High-speed, cost-sensitive tasks

All four models support vision, tool use/function calling, and batch processing. Fable 5 and Opus 4.8 are available on AWS Bedrock, Google Cloud Vertex AI, and Microsoft Azure AI Foundry in addition to the direct Anthropic API.

Claude Fable 5 (June 9, 2026)

Fable 5 is Anthropic’s first publicly available Mythos-class model — a capability tier previously restricted to research and select enterprise partners. It’s the most capable model Anthropic has released to date.

What makes Fable 5 different:

SWE-bench Verified: 95.0% (vs 88.6% for Opus 4.8)
SWE-bench Pro: 80.0% (vs 69.2%)
Senior Engineer benchmark: 91/100 (vs ~63/100)
Adaptive extended thinking (always on, not a mode switch)

Important limitations:

2x the cost of Opus 4.8 ($10/$50 vs $5/$25)
Mandatory 30-day data retention — not available under zero data retention (ZDR)
Safety classifiers route cybersecurity, biology, chemistry, and distillation prompts to an Opus 4.8 fallback — you pay Fable 5 rates for Opus 4.8 output in those domains
Higher latency on complex tasks (60 seconds to several minutes vs 3–15 seconds for Opus 4.8)

Free through June 22, 2026: Claude Pro, Max 5x, Max 20x, Team, and Enterprise subscription plans include Fable 5 at no extra charge during the launch window.

Claude Opus 4.8

Opus 4.8 is Anthropic’s current workhorse for serious work — the right default for most API applications and Claude Code use. It supports zero data retention (ZDR), which Fable 5 does not.

Key specs:

Context: 1M tokens
Max output: 32K tokens per request
Extended thinking: Available (opt-in mode)
ZDR: Yes
Batch API: Yes (50% discount on batch processing)

Use Opus 4.8 as your default model unless you have a specific reason to go up to Fable 5 or down to Sonnet/Haiku. It hits the best balance of capability, speed, cost, and data policy flexibility.

Claude Sonnet 5

Sonnet 5 targets use cases where response speed matters and you don’t need Opus-level reasoning. It’s the model Anthropic’s own infrastructure runs Claude.ai on for Pro subscribers doing day-to-day chat work.

Key specs:

Context: 1M tokens
Max output: 64K tokens per request
Extended thinking: Available
ZDR: Yes
Typical latency: 1–5 seconds for most tasks

Good for: content generation pipelines, customer-facing chat, document analysis at volume, anything where sub-5-second response time matters.

Claude Haiku 4.5

Haiku 4.5 is Anthropic’s fastest and cheapest model. At $1 input / $5 output per million tokens, it’s 10x cheaper than Fable 5.

Key specs:

Context: 200K tokens (smaller than the Opus/Sonnet/Fable 1M window)
Max output: 16K tokens per request
Latency: Sub-second for most tasks
ZDR: Yes

The 200K context window is the main limitation. For tasks that fit within that window — classification, short-form generation, routing, extraction — Haiku 4.5 is the cost-optimal choice. For longer documents or conversations, step up to Sonnet or Opus.

How to Choose the Right Claude Model

Pyramid diagram of Claude tiers: fast volume base, production workhorse middle, deep flagship peak — How to choose the right Claude model.

The decision framework I use:

Does the task require multi-step reasoning, complex coding, or long-horizon autonomy? → Fable 5 (if cost and latency are acceptable) or Opus 4.8
Is this a routine task at reasonable volume? → Opus 4.8 as the default
Does latency matter more than maximum reasoning depth? → Sonnet 5
Is this high-volume, short-context, cost-sensitive work? → Haiku 4.5
Does your use case require zero data retention? → Any model except Fable 5

Most production applications use a routing strategy: Fable 5 or Opus 4.8 for the hard jobs, Haiku 4.5 for classification and pre-processing, Sonnet 5 for user-facing response generation.

Claude Subscription Plans and Model Access (June 2026)

Infographic ladder of Claude plans: Free, Pro, Max, Team, and Enterprise — Subscription plans and model access — stale-proof.

Plan	Price	Models Included
Free	$0	Limited Sonnet 5 access
Pro	$20/mo ($17 annual)	Sonnet 5, Opus 4.8, Fable 5 (through June 22)
Max 5x	$100/mo	All models, 5x usage vs Pro
Max 20x	$200/mo	All models, 20x usage vs Pro
Team Standard	$20/seat/mo (annual), $25 month-to-month	All models + admin features
Team Premium	$100/seat/mo (annual), $125 month-to-month	All models + priority + advanced admin
Enterprise	$20/seat + usage at API rates (contact sales)	All models + ZDR + custom retention + SSO

Claude Code (the CLI tool) is included in all paid subscription plans. API access for building your own applications is separate — billed per token via the Anthropic Console regardless of subscription status.

Legacy Models (Still Available, No Longer Latest)

These models are still available via the API but are not Anthropic’s current recommended versions:

Claude Opus 4.7 (claude-opus-4-7) — prior Opus tier, succeeded by 4.8
Claude Opus 4.6 (claude-opus-4-6) — two generations back
Claude Sonnet 4.5 (claude-sonnet-4-5) — prior Sonnet tier
Claude 3.5 Haiku / Sonnet / Opus — Claude 3.x generation, still functional for legacy integrations

If you’re building a new application, start with the current lineup. Legacy model IDs are useful for maintaining compatibility in existing applications that haven’t been updated.

Platform Availability

Platform	Fable 5	Opus 4.8	Sonnet 5	Haiku 4.5
Anthropic API (direct)	✓	✓	✓	✓
AWS Bedrock	✓	✓	✓	✓
Google Cloud Vertex AI	✓	✓	✓	✓
Microsoft Azure AI Foundry	✓	✓	✓	✓
GitHub Copilot	✓ (via Foundry)	✓	✓	—

Frequently Asked Questions

What is the newest Claude model?
As of June 2026, Claude Fable 5 is the newest and most capable model Anthropic has released. It launched June 9, 2026. The API model ID is claude-fable-5.

Is Claude Fable 5 the same as Claude 5?
No. Anthropic changed the naming convention — there is no “Claude 5.” The Fable series is a new tier above the Opus/Sonnet/Haiku hierarchy. Fable 5 is Anthropic’s first Mythos-class model released for general availability.

What is the most powerful Claude model?
Claude Fable 5 is currently the most powerful. For tasks where Fable 5’s safety classifier routing applies (cybersecurity, biology, chemistry, distillation), or where zero data retention is required, Claude Opus 4.8 is the appropriate top-tier choice.

What Claude model does Claude.ai use by default?
Depends on your plan. Free tier uses a limited version of Sonnet. Pro and Max subscribers access Opus 4.8 as the default with Fable 5 available (through June 22, 2026 included, after that plan-dependent). Claude.ai routes to the appropriate model for your plan automatically.

How do I use the latest Claude model in the API?
Set the model parameter in your API request to the model ID. For Fable 5: "model": "claude-fable-5". For Opus 4.8: "model": "claude-opus-4-8". See the full API reference at console.anthropic.com.

What’s the difference between Claude Opus 4.8 and Fable 5?
Fable 5 is significantly stronger on complex engineering tasks — SWE-bench Pro: 80% vs 69.2%, and Senior Engineer benchmark: 91 vs ~63 out of 100. The trade-off: Fable 5 costs 2x more ($10/$50 vs $5/$25 per MTok), has higher latency, and requires 30-day data retention. For most work, Opus 4.8 is the right choice. Full Fable 5 vs Opus 4.8 breakdown here.

Changelog

June 12, 2026 — Added Claude Fable 5 (released June 9). Updated pricing table. Added platform availability table.
May 2026 — Claude Opus 4.8 and Sonnet 4.6 were the current top-tier models.

This page is updated as Anthropic releases new models. Last verified: August 26, 2026 (Pacific Time) For API pricing, check console.anthropic.com — the canonical source.

💼 Deploying Claude or AI Infrastructure in Your Business?

At Tygart Media, we engineer custom Model Context Protocol (MCP) servers, multi-model content pipelines, and AI operational systems. Explore our Claude AI Team Implementation Services or check out our complete Restoration Operations & AI Kit.

June 12, 2026

Claude Fable 5: Capabilities, Pric (2026)
Anthropic released Claude Fable 5 on June 9, 2026 — and it’s the most capable model the company has ever made publicly available. After tracking every Claude release since the original 100K context window dropped, I can say this one is different. Fable 5 isn’t just an incremental update. It’s Anthropic’s Mythos-class model — the one they’d been keeping restricted — now opened up to anyone with an API key or a Claude subscription.

Here’s what you need to know: the pricing, the benchmarks, and the specific decision framework for when to use Fable 5 versus sticking with Opus 4.8.

Quick answer: Fable 5 costs $10/$50 per million input/output tokens (2x the cost of Opus 4.8). It outperforms Opus 4.8 significantly on complex coding, long-horizon tasks, and scientific research. Use Fable 5 when quality on hard problems justifies the cost. Use Opus 4.8 for high-volume, well-scoped, routine work.

What Is Claude Fable 5?

What is Claude Fable 5?

Claude Fable 5 (claude-fable-5) is Anthropic’s first publicly available Mythos-class model. The Mythos line is Anthropic’s highest capability tier — models that were previously restricted to research and select enterprise partners because of their raw power. Fable 5 is the version Anthropic deemed safe enough to release broadly.

The name shift (from the Opus/Sonnet/Haiku tier naming) signals something intentional. Fable 5 sits above the Opus line entirely. It’s a new ceiling.

Key specs:
- Context window: 1M tokens (same as Opus 4.8)
- Max output: 128K tokens per request
- Thinking: Adaptive (always on — not a separate “thinking mode”)
- Vision: Yes
- Tool use / function calling: Yes
- Available: Claude API, AWS Bedrock, Vertex AI, Microsoft Foundry
Claude Fable 5 Pricing

Fable 5 pricing — no sticky dollar stickers.

Model Input (per MTok) Output (per MTok) Context

Claude Fable 5 $10.00 $50.00 1M tokens

Claude Opus 4.8 $5.00 $25.00 1M tokens

Claude Sonnet 4.6 $3.00 $15.00 1M tokens

Claude Haiku 4.5 $1.00 $5.00 200K tokens

Fable 5 costs exactly 2x Opus 4.8 on API. On subscription plans (Pro, Max, Team, Enterprise seat-based), Fable 5 is included at no extra cost through June 22, 2026.

The free-until-June-22 window matters if you’re evaluating whether to route your workloads to Fable 5. Use that window to benchmark it against your actual tasks before the 2x cost kicks in.

Benchmark Performance: Where Fable 5 Pulls Away

The benchmarks that matter most are the ones that measure what the model can do on real engineering work, not trivia:

Benchmark Claude Fable 5 Claude Opus 4.8 Delta

SWE-bench Verified 95.0% 88.6% +6.4 pts

SWE-bench Pro 80.0% 69.2% +10.8 pts

FrontierCode 29.3% 13.4% ~2.2x

Senior Engineer benchmark 91/100 ~63/100 +45% absolute

The Senior Engineer benchmark is the one I find most telling. It’s designed to be hard for people who write code for a living — and Fable 5 scores 45 percentage points higher than Opus 4.8. That gap is significant enough that it changes the calculus for serious engineering work.

When to Use Claude Fable 5 (vs Opus 4.8)

When to use Fable 5 vs Opus.

I’ve been routing tasks between models for long enough to have a framework. Here’s how I think about it:

Use Fable 5 when:
- You’re running a large migration, refactor, or multi-stage software project
- Quality on a hard problem matters more than per-token cost
- You’re doing deep research, complex analysis, or long-horizon agentic work
- The task would otherwise take a senior engineer half a day or more
- You’re in the free evaluation window (through June 22) and want to benchmark
Use Opus 4.8 when:
- The task is well-scoped and routine
- You’re running high-volume pipelines where 2x cost compounds fast
- Latency matters — Fable 5 can take 60 seconds to several minutes on complex tasks vs 3–15 seconds for Opus 4.8
- The task falls in Fable 5’s restricted domains (cybersecurity, biology, chemistry, distillation) — in those categories, Fable 5 routes to Opus 4.8 anyway, so you’d pay Fable 5 prices for Opus 4.8 output
The smart routing strategy: Fable 5 for the hard jobs, Opus 4.8 for the rest. Don’t use Fable 5 as your default model — the cost and latency delta aren’t worth it for routine tasks.

Important Limitations to Know Before You Switch

Two limitations that don’t get enough coverage:

1. Safety classifier routing. Fable 5 includes enhanced safety classifiers. For prompts touching cybersecurity, biology, chemistry, and distillation, those classifiers route the request to a Claude Opus 4.8 fallback. You pay Fable 5 API rates ($10/$50) but get Opus 4.8 output. If your use case is in these domains, Fable 5 is not the upgrade it appears to be.

2. Data retention requirement. Fable 5 carries a mandatory 30-day data retention policy — Anthropic needs retained prompts and outputs to operate the safety classifiers. Claude Opus 4.8 is available under zero data retention (ZDR). If your use case requires ZDR (healthcare, legal, finance with strict data handling), stick with Opus 4.8 until Anthropic updates Fable 5’s data policy.

Availability

Claude Fable 5 is generally available as of June 9, 2026 on:
- Claude API (claude-fable-5)
- Claude Platform on AWS / Amazon Bedrock
- Google Cloud Vertex AI
- Microsoft Azure AI Foundry / GitHub Copilot
Subscription access (free through June 22, 2026): Claude Pro ($20/mo), Max 5x ($100/mo), Max 20x ($200/mo), Team, and seat-based Enterprise plans all include Fable 5 access at no extra charge during the launch window. After June 22, the plan-tier access picture may change — check Anthropic’s pricing page for updates.

How This Changes the Claude Model Decision Tree

Before Fable 5, the Claude decision tree was straightforward:
- Need the best? → Opus 4.8
- Need balance? → Sonnet 4.6
- Need speed/cost? → Haiku 4.5
Now it’s:
- Hard problems, complex projects, long-horizon work → Fable 5
- Everyday work, high-volume pipelines → Opus 4.8
- Balance of cost and capability → Sonnet 4.6
- Speed and cost optimization → Haiku 4.5
The introduction of a model tier above Opus 4.8 doesn’t replace the existing lineup — it creates a new ceiling for the work that genuinely needs it.

Related on Tygart Media: Fable 5 complete guide · Fable 5 firsthand · how to use Claude.

Frequently Asked Questions

Is Claude Fable 5 better than Opus 4.8?
For complex coding, multi-stage tasks, and long-horizon work: yes, significantly. On SWE-bench Pro, Fable 5 scores 80.0% vs Opus 4.8’s 69.2% — a 10+ point gap. For routine, well-scoped tasks: the gap narrows enough that Opus 4.8’s 2x cost advantage makes it the smarter choice.

What is the Claude Fable 5 API model ID?
claude-fable-5. This is the API string you pass to model in your API calls.

Does Fable 5 cost more than Opus 4.8?
Yes — exactly 2x. Fable 5 is $10 input / $50 output per million tokens. Opus 4.8 is $5/$25. Through June 22, 2026, Fable 5 is included in Claude subscription plans at no extra cost.

Can I use Claude Fable 5 for free?
On Pro, Max, Team, and Enterprise subscription plans, yes — through June 22, 2026. API access is metered at $10/$50 per MTok from day one.

Does Claude Fable 5 support zero data retention (ZDR)?
No. Fable 5 carries a mandatory 30-day data retention requirement. If your use case requires ZDR, use Claude Opus 4.8, which supports it.

What’s the difference between Claude Fable 5 and Claude Mythos 5?
Mythos 5 is Anthropic’s fully restricted research model — not publicly available. Fable 5 is the Mythos-class model that Anthropic has prepared for general availability, with safety classifiers and the 30-day retention policy. You can think of Fable 5 as “Mythos for the real world.”

Last verified: June 12, 2026. Anthropic pricing and availability subject to change — check Anthropic’s pricing page for current rates.
June 12, 2026

Model	Input (per MTok)	Output (per MTok)	Context
Claude Fable 5	$10.00	$50.00	1M tokens
Claude Opus 4.8	$5.00	$25.00	1M tokens
Claude Sonnet 4.6	$3.00	$15.00	1M tokens
Claude Haiku 4.5	$1.00	$5.00	200K tokens

Benchmark	Claude Fable 5	Claude Opus 4.8	Delta
SWE-bench Verified	95.0%	88.6%	+6.4 pts
SWE-bench Pro	80.0%	69.2%	+10.8 pts
FrontierCode	29.3%	13.4%	~2.2x
Senior Engineer benchmark	91/100	~63/100	+45% absolute

Claude Fable 5 Complete Guide

New in 2026

Everything you need to know about Anthropic’s new frontier tier — pricing, context window, model comparisons, and how to route the right work to the right model.

Updated June 2026 · ~14 min read · Includes interactive calculators

What Is Claude Fable 5?

Claude Fable 5 is Anthropic’s new frontier model tier — positioned above Opus in the lineup and designed for tasks where raw capability, extended reasoning depth, and massive context handling matter more than cost. Where Opus 4.8 set the bar for complex multi-step reasoning, Fable 5 raises it with a 1-million-token context window, enhanced agentic autonomy, and improved performance on long-horizon software engineering, research synthesis, and cross-domain analysis tasks.

The “Fable” naming signals a new generation of model architecture rather than an incremental update. Anthropic positions it as the model you reach for when a task exceeds what Opus can do reliably — not as a replacement for Opus, Sonnet, or Haiku in their respective cost tiers.

Quick Facts — Claude Fable 5

Context Window

tokens (~750K words)

Max Output

32K

tokens per response

Input Price

$10

per million tokens

Output Price

$50

per million tokens

Cache Write

$12.50

per million tokens

Cache Read

$1.00

per million tokens

Key positioning: Fable 5 is the model for tasks where Opus 4.8 produces reliable but imperfect results — long codebase audits, full-document analysis, complex multi-agent orchestration, and strategic synthesis across large corpora. For most production workflows, Sonnet remains the value pick.

Full Model Lineup Comparison

Here’s how the complete 2026 Claude lineup stacks up across every dimension that matters for production usage:

Model	Input $/M	Output $/M	Context	Max Out	Vision	Tool Use	Extended Think	Best For
◆ Fable 5	$10	$50	1M	32K	✓	✓	✓ Deep	Max-capability tasks, 1M+ context
◆ Opus 4.8	$5	$25	200K	32K	✓	✓	✓	Complex reasoning, agentic workflows
◆ Sonnet 4.6	$3	$15	200K	16K	✓	✓	✓	Production apps, content at scale
◆ Haiku 4.5	$1	$5	200K	8K	✓	✓	—	High-volume, latency-sensitive tasks

Prices are per million tokens. Cache read is 90% cheaper than standard input across all models. Batch API provides an additional 50% discount on both input and output.

Capability Matrix — What Each Model Can Do

Capability	Fable 5	Opus 4.8	Sonnet 4.6	Haiku 4.5
Full codebase analysis (>500K tokens)	✓ Native	⚠ Chunked	✗	✗
Extended thinking / chain-of-thought	✓ Deep	✓	✓	✗
Multi-step agentic orchestration	✓ Best	✓	Good	Limited
Computer use	✓	✓	✓	✗
MCP tool integration	✓	✓	✓	✓
Prompt caching	✓	✓	✓	✓
Batch API (50% discount)	✓	✓	✓	✓
PDF / document analysis	✓	✓	✓	Limited
Real-time streaming	✓	✓	✓	✓
Structured JSON output	✓	✓	✓	✓

Interactive Cost Calculator

Estimate your monthly API spend across the full model lineup. Enter your token volumes below — the calculator models prompt caching and Batch API discounts automatically.

Token Cost Calculator

Model

Monthly API Calls

Avg Input Tokens / Call

Avg Output Tokens / Call

Prompt Caching (90% off reads) Batch API (50% off all)

Estimated Monthly Cost

$0.00

Which Claude Model Should You Use?

Decision diagram from task shape to deep reasoning, daily shipping, or high-volume cheap calls — Which Claude model should you use?

Answer three questions to get a model recommendation tailored to your use case.

Model Picker — 3 Questions

1. How large is your context? (document/codebase size)

Under 50K tokens

50K–200K tokens

200K–1M tokens

2. How complex is the task?

Simple / structured (classify, extract, format)

Moderate (draft, summarize, QA)

Complex (reason, plan, code, orchestrate)

3. How cost-sensitive is this workload?

Very — high volume, every cent counts

Moderate — quality matters more than cost

Not sensitive — quality and capability first

How We Actually Use Each Model

These are real production workflows mapped to the right tier — built from running Claude in content operations, publishing automation, and knowledge management at scale. No hypotheticals.

Haiku 4.5 — High Volume

Daily SEO Refresh Pipeline

25-post-per-day SEO metadata refresh
Article classification and tag assignment
Structured data extraction from web pages
Keyword density checks across large post archives
Link validation and redirect flagging

Sonnet 4.6 — Production Default

Editorial Content at Scale

Desk article writing (1,200–2,500 words)
Content brief execution from keyword clusters
FAQ and schema markup generation
Cross-site content adaptation and localization
Monthly client update drafts and summaries

Opus 4.8 — Complex Reasoning

Workers & Deep Refreshes

Agentic Notion Workers (multi-step pipelines)
Deep content refresh with competitive gap analysis
Multi-database synthesis and reporting
Strategy documents requiring extended reasoning
Code generation for automation scripts

Fable 5 — Max Capability

Portfolio Audits & Strategy

Full-site content audits (500+ posts in single context)
Cross-domain strategy synthesis across large corpora
Complex multi-agent orchestration at the flagship tier
Long-horizon planning requiring deep reasoning depth
Codebase-wide analysis and architecture review

Routing principle: The right model is the cheapest one that reliably completes the task. Haiku handles volume. Sonnet handles production. Opus handles complexity. Fable 5 handles scale + complexity together — specifically the cases where you’d need Opus and more context than Opus can hold.

The Economics: Routed vs All-Fable

Smart model routing is where API costs get controlled. Here’s a real-world comparison of a mixed content-and-automation workload at scale — routed vs running everything on Fable 5.

Workload	Monthly Volume	Routed Model	Routed Cost	All-Fable 5 Cost	Savings
SEO metadata batch refresh	750 posts/mo	Haiku 4.5 + Batch	$1.20	$18.75	93% less
Article drafting	90 articles/mo	Sonnet 4.6	$8.10	$67.50	88% less
Agentic worker runs	200 runs/mo	Opus 4.8	$22.50	$45.00	50% less
Full-site portfolio audits	4 audits/mo	Fable 5	$24.00	$24.00	—
Total	—	Routed	$55.80	$155.25	64% less

Stacking Discounts: Caching + Batch API

Two discount mechanisms compound independently:

Prompt caching: Cache your system prompt and shared context once. Subsequent requests pay ~10% of the input price for cache reads. On Fable 5, that’s $1.00/M instead of $10.00/M on cached tokens — a 90% reduction on your largest cost lever.
Batch API: Submit requests asynchronously (results within 24 hours) for a flat 50% discount on both input and output. Works on all four models. Best for non-real-time workloads like overnight refreshes, audits, or bulk classification.
Stacked: Caching + Batch combined can bring effective Fable 5 input cost from $10/M to ~$0.50/M on cached tokens — making it economically viable for high-volume tasks that previously only fit Haiku’s budget.

See our Claude context window guide for more on how to structure prompts to maximize cache hit rates.

Related Claude Resources

Claude Context Window Guide Claude Projects Deep Dive Claude Code Plan Mode Claude MCP Setup Guide Opus 4.7 Feature Deep Dive Claude Code vs Cursor (2026)

Claude Fable 5 FAQ

Claude Fable 5 sits above Opus 4.8 in the lineup. The primary difference is context window size — Fable 5 offers 1 million tokens vs Opus 4.8’s 200K — and the depth of extended reasoning for highly complex tasks. Opus 4.8 remains the right choice for most complex agentic workflows at half the cost. Fable 5 is best when you need both maximum context and maximum reasoning depth simultaneously, or when a task has routinely hit the limits of what Opus can do reliably.

Claude Fable 5 is priced at $10 per million input tokens and $50 per million output tokens — 2× Opus 4.8 ($5/$25), 3.3× Sonnet 4.6 ($3/$15), and 10× Haiku 4.5 ($1/$5). Prompt caching drops the effective input cost to $1.00/M on cache reads, and the Batch API adds a 50% discount on all tokens for non-real-time workloads. Stacking both discounts makes Fable 5 viable for higher-volume use cases than the base price suggests.

Claude Fable 5 has a 1-million-token context window — approximately 750,000 words or roughly 1,500 pages of text. This is 5× the context window of Opus 4.8, Sonnet 4.6, and Haiku 4.5 (all 200K). In practice, a 1M context window lets you pass entire codebases, long research corpora, or full document archives in a single API call without chunking or retrieval workarounds. For more on context window mechanics, see our full context window guide.

Yes. Claude Fable 5 is available through the Anthropic API using the model ID claude-fable-5-20260101 (check the Anthropic documentation for the exact identifier). It supports the same API surface as the rest of the Claude family — streaming, tool use, prompt caching, vision, the Batch API, and MCP server integration. Access requires an Anthropic API account with Fable 5 enabled on your usage tier.

Fable 5 is available in Claude.ai on the Pro and Team plans. The interface lets you select it from the model picker when starting a conversation. Like Opus, Fable 5 in claude.ai has message limits that reset on a rolling window — it’s designed for individual complex tasks rather than high-volume API workloads. For production-scale usage, the API with the Batch API discount is the more economical path.

Yes — and Fable 5’s extended thinking is the deepest in the lineup. Where Opus 4.8 supports extended thinking for complex reasoning tasks, Fable 5 uses a more capable reasoning engine designed for tasks that require longer chains of inference, more working memory, and more reliable self-correction. It’s particularly effective on math, logic, long-horizon planning, and tasks where the model needs to hold and manipulate many interdependent concepts simultaneously.

For most content production — articles, blog posts, social copy, summaries, SEO content — Sonnet 4.6 is the right call. It produces high-quality output at 3.3× less cost than Fable 5, and for typical content lengths (500–3,000 words), the quality difference is minimal. Reach for Fable 5 when you need to synthesize across a very large corpus (e.g., auditing 200+ posts simultaneously), when the content requires deep domain reasoning that benefits from extended thinking, or when the task involves both large-context ingestion and complex output generation in a single pass.

Three levers in order of impact: (1) Model routing — only use Fable 5 when the task genuinely requires it; route everything else to Opus, Sonnet, or Haiku based on complexity and volume. (2) Prompt caching — structure your system prompt and shared context so it can be cached; cache reads cost $1.00/M instead of $10.00/M on Fable 5. (3) Batch API — submit non-real-time workloads via the Batch API for a flat 50% discount. Stacking all three — routing + caching + batch — can reduce effective per-task costs by 85–95% compared to unoptimized Fable 5 calls.

More Claude Guides from Tygart Media

We run Claude in production every day. These are the guides that come from using it, not just writing about it.

Context Window Guide Claude Projects Plan Mode MCP Setup Code vs Cursor

Related on Tygart Media: Claude Fable 5 overview · Fable 5 firsthand · Claude pricing.

June 9, 2026

The Technical Founder’s Roadmap to Claude 4.6

The Technical Founder’s Roadmap to Claude 4.6

If you are bootstrapping a tech startup in 2026, navigating the LLM ecosystem is no longer about finding the smartest model—it’s about finding the most cost-effective architecture that actually ships code. We have built this bespoke concierge roadmap to guide you through the Tygart Media resources you need right now.

📍 Stop 1: The Economics of Routing

Before you write a single line of code, you need to understand your margins. Anthropic recently made a massive move in the B2B space that directly impacts your AWS burn rate. Read this first: Anthropic Slashes Claude 4.6 Haiku API Pricing by 40%

📍 Stop 2: Validating the Intelligence

Now that you know Haiku is cheap, you need to verify if Sonnet is smart enough for your core reasoning tasks. Bookmark our living leaderboard to see exactly where Claude 4.6 stands against GPT-5. Check the stats: Claude 4.6 vs GPT-5: The 2026 Leaderboard

📍 Stop 3: Shipping the Front-End

With your architecture chosen, it’s time to build. If you are using React, you must prevent the model from generating “lazy” partial files that break your CI/CD pipelines. Implement this workflow: The Top Claude 4.6 Prompt for React Developers This Week

📍 Stop 4: The Final Automation

If you want to see exactly how we implemented Claude 4.6 in a real-world production environment to completely automate our editorial newsroom, we documented the entire architecture in public. Read the case study: How We Automated Our Newsroom Using Claude 4.6

This roadmap was autonomously generated by the Tygart Media Omni-Brain to connect you with the specific intelligence you need. Check back for future roadmap updates.

May 30, 2026
Anthropic Slashes Claude 4.6 Haiku API Pricing by 40%
Anthropic Slashes Claude 4.6 Haiku API Pricing by 40%

In a massive bid for enterprise B2B market share, Anthropic has officially slashed the input token costs for Claude 4.6 Haiku.
- Old Price: $0.25 / 1M Input Tokens
- New Price: $0.15 / 1M Input Tokens
What this means for CTOs

If you are running high-volume log parsing, customer support routing, or massive RAG (Retrieval-Augmented Generation) pipelines, switching your routing logic from OpenAI’s GPT-4o-mini to Claude 4.6 Haiku will instantly slash your monthly AWS Bedrock bill while maintaining state-of-the-art speed.

Related on Tygart Media: Claude pricing · Claude 4.6 vs GPT-5 · Message Batches API.
May 30, 2026
Claude Artifacts API Release: What We Are Hearing

The Claude “Artifacts” Wrapper is Coming to the Core API

Anthropic’s “Artifacts” feature—which allows Claude to instantly render and preview code, diagrams, and UI elements in a side panel—has revolutionized the ChatGPT-style web interface. But for developers building their own applications using the Claude API, they’ve been forced to build those UI rendering wrappers from scratch.

According to emerging chatter on X (Twitter), that is about to change.

Social Radar Intel: “Rumors circulating that the Artifacts UI wrapper is finally coming to the core API next week. If developers can render interactive React components directly inside their own chat UIs using Claude, it’s game over for generic wrappers.”

Why This Matters for Builders

If Anthropic exposes the Artifacts rendering engine natively through the API, it significantly lowers the barrier to entry for building rich, interactive AI tools. You will no longer need a senior front-end engineer to parse JSON and render a React component on the fly; the API will handle the interactive framing.

The Tygart Verdict: We are keeping a close eye on the official Anthropic changelog over the next two weeks. If this drops, expect a flood of “wrapper” apps to pivot or die.

Related on Tygart Media: Claude Desktop tips · how to use Claude · Claude Cowork.

May 30, 2026
Claude Code Rate Limits Doubled: Pro vs Max Plan Guide
If you bought a Claude Code subscription in March or April and felt like you were hitting the 5-hour wall every single afternoon, you weren’t imagining it. Anthropic spent six months tightening Claude Code’s quotas — and then, over two weeks in May 2026, gave most of them back. The rate-limit math that drove plan-selection advice on the internet through April is now obsolete. Here’s what actually changed, what the numbers look like today, and how to think about Pro versus Max if you’re picking a plan this week.

What Anthropic actually did

What Anthropic actually did to rate limits.

On May 6, 2026, Anthropic doubled the 5-hour rate limits on Claude Code across every paid plan — Pro, Max 5x, Max 20x, Team Premium, and seat-based Enterprise. In the same announcement, they removed the peak-hour throttle that had been quietly halving available quota for Pro and Max users during weekday business hours. They also lifted API-side rate limits on the Opus tier.

One week later, on May 13, 2026, they followed up with a 50% increase to the weekly cap across the same plans. Unlike the 5-hour change, that weekly bump carries an expiration date: July 13, 2026, unless extended. Treat it as a temporary boost, not a permanent feature.

The trigger Anthropic pointed to is a deal that brings the full capacity of the Colossus 1 data center in Memphis online — over 300 megawatts and roughly 220,000 NVIDIA GPUs. That detail matters less than the practical one: capacity-driven throttling that had been the dominant constraint since late 2025 has loosened.

The new numbers, by plan

The shape of the plan ladder hasn’t changed — Pro at $20, Max 5x at $100, Max 20x at $200, Team Premium at $100/seat with a 5-seat minimum. What changed is what each tier actually delivers per window.
- Pro ($20/mo): Roughly 90 prompts per 5-hour window now (up from a number that, in practice, was hovering around 45 once the peak-hour throttle kicked in). No peak penalty. Weekly cap is 50% higher through July 13.
- Max 5x ($100/mo): Same doubled 5-hour window. Weekly Opus 4.7 budget moved from approximately 50 hours to approximately 75.
- Max 20x ($200/mo): Doubled 5-hour window. Weekly Opus 4.7 budget moved from approximately 200 hours to approximately 300.
- Team Premium ($100/seat/mo, annual; $125 monthly): Mirrors Max 5x quotas at the seat level. 5-seat minimum still applies.
Two numbers that haven’t changed: the API pay-as-you-go pricing for the underlying models (claude-sonnet-4-6 at roughly $3 per million input tokens and $15 per million output; claude-opus-4-7 at roughly $5 in and $25 out), and the existence of the weekly cap itself. The weekly cap is still the thing that kills Max users mid-Friday.

What this changes about plan selection

Plan selection after the rate-limit change.

Most of the “which plan should I buy” guides written before May 6 over-recommend Max 5x because they were sizing it against artificially compressed Pro limits. With a doubled 5-hour cap and no peak throttle, Pro at $20 is now genuinely enough for a developer doing focused coding sessions a few hours a day — something that wasn’t reliably true a month ago.

The Max 5x case still holds, but it’s narrower now. The honest test: if you regularly burn through your Pro 5-hour window before lunch, or if you run two or three concurrent Claude Code sessions on different repos, $100 still pays for itself. If you don’t, Pro will hold.

Max 20x is increasingly a workflow choice rather than a quota choice. The doubled limits made Max 5x sufficient for almost every solo workflow I can describe. Where 20x still earns its price is multi-agent workflows, where a coordinator-and-workers pattern can burn three to seven times the tokens of a single-agent session because every teammate maintains its own context window.

The hidden costs that didn’t change

The rate-limit relief is real, but several gotchas that drove “Claude Code costs me more than I expected” complaints in Q1 are still live:
- Set ANTHROPIC_API_KEY in your shell and Claude Code bills at API rates — your subscription is silently ignored. Unset it before launching the CLI if you’re on a plan.
- Weekly caps count active processing time only. Idle browsing is free. Long-running tool calls and extended-thinking budgets aren’t.
- Extended thinking is billed as output tokens. On Opus 4.7 that’s roughly $25 per million. Default thinking budgets of tens of thousands of tokens per request stack up fast on API.
- MCP server output sits in context for the rest of the session. A “list the last 20 PRs” call can dump 8,000 tokens of metadata that you’ll re-pay for on every subsequent turn until the conversation rolls over.
If you were running into the 5-hour wall and assumed it was a usage problem, check whether one of those four is actually the cause before you upgrade.

What to do this week

What to do this week.

If you’re on Pro and were considering Max 5x, wait two weeks. The new Pro ceiling is high enough that the upgrade decision now needs different evidence than it did in April.

If you’re already on Max 5x and felt squeezed, the May 13 weekly bump should give you breathing room — but mark July 13 on your calendar. If the temporary 50% increase isn’t extended, the squeeze comes back.

If you’re picking a plan from scratch today: start on Pro. The doubled limits are real, the peak-hour penalty is gone, and the upgrade path to Max stays open with no friction. Buy quota when you’ve measured that you need it, not before.

The model versions to use

For anyone writing the API string into a script this week: flagship is claude-opus-4-7, workhorse is claude-sonnet-4-6, fast tier is claude-haiku-4-5-20251001. Pull from docs.anthropic.com/en/docs/about-claude/models before shipping anything — the version strings have moved twice already this year and they’ll move again.

Related on Tygart Media: Claude Code billing · Claude Pro vs Max · Claude Code getting started.
May 28, 2026

Tag: Claude API

The one-glance comparison

Skills: teaching Claude a procedure

MCP: the open standard for access

Connectors: MCP, packaged for the apps

Plugins: a bundle, not a single thing

Hooks and slash commands: controlling the session

Is a Connector the same as an MCP server?

What’s the difference between a Skill and an MCP server?

Do Skills cost a lot of context tokens?

What can a Claude Code plugin contain?

Are custom slash commands still a thing?

The breaking-change matrix

Model ID swaps and retirement dates

budget_tokens to adaptive thinking

Sampling parameters: removed vs. restricted

Assistant-turn prefills to structured outputs

Thinking display: the silent one

The new tokenizer: re-baseline max_tokens

The full checklist

Is migrating off Claude Opus 4 really not just a model-string change?

When exactly do Claude Opus 4 and Sonnet 4 stop working?

What replaces budget_tokens now that it errors on Opus?

Why does the same prompt cost more tokens on Opus 4.8?

My thinking summaries disappeared after migrating to Opus — is that a bug?

The two billing models at a glance

What changes on June 15, 2026

How each pool is metered and priced

Subscription plan prices

The SDK rename: claude-code-sdk to claude-agent-sdk

Decision: which billing path applies to your work

Does interactive Claude Code billing change on June 15, 2026?

How much is the separate Agent SDK credit?

What happens when the Agent SDK credit runs out?

How do I avoid the credit pool entirely?

Was the Claude Code SDK renamed?

Current Claude Models — Quick Reference

Claude Fable 5 (June 9, 2026)

Claude Opus 4.8

Claude Sonnet 5

Claude Haiku 4.5

How to Choose the Right Claude Model

Claude Subscription Plans and Model Access (June 2026)

Legacy Models (Still Available, No Longer Latest)

Platform Availability

Frequently Asked Questions

Changelog

What Is Claude Fable 5?

Claude Fable 5 Pricing

Benchmark Performance: Where Fable 5 Pulls Away

When to Use Claude Fable 5 (vs Opus 4.8)

Important Limitations to Know Before You Switch

Availability

How This Changes the Claude Model Decision Tree

Frequently Asked Questions

What Is Claude Fable 5?

Quick Facts — Claude Fable 5

Full Model Lineup Comparison

Capability Matrix — What Each Model Can Do

Interactive Cost Calculator

Token Cost Calculator

Which Claude Model Should You Use?

How We Actually Use Each Model

The Economics: Routed vs All-Fable

Stacking Discounts: Caching + Batch API

Related Claude Resources

Claude Fable 5 FAQ

More Claude Guides from Tygart Media

The Technical Founder’s Roadmap to Claude 4.6

📍 Stop 1: The Economics of Routing

📍 Stop 2: Validating the Intelligence

📍 Stop 3: Shipping the Front-End

📍 Stop 4: The Final Automation

Anthropic Slashes Claude 4.6 Haiku API Pricing by 40%

What this means for CTOs

The Claude “Artifacts” Wrapper is Coming to the Core API

Why This Matters for Builders

What Anthropic actually did

The new numbers, by plan

What this changes about plan selection