Anthropic - OpenClaw

Anthropic builds the Claude model family. OpenClaw supports two auth routes:

API key - direct Anthropic API access with usage-based billing (anthropic/* models)
Claude CLI - reuse an existing Claude Code login on the same host

Usage and cost tracking

OpenClaw detects the available Anthropic credential and selects the matching usage surface:

Claude subscription/setup credentials show quota windows and optional extra-usage budget.
ANTHROPIC_ADMIN_KEY or ANTHROPIC_ADMIN_API_KEY shows 30 days of provider-reported organization cost and Messages API usage in Control UI Usage, including daily spend, token/cache totals, top models, and cost categories.
An sk-ant-admin... credential stored in the Anthropic provider profile is detected as an Admin API key automatically.

Admin API cost history comes from Anthropic’s Usage and Cost API. It is actual provider billing, separate from OpenClaw’s session-derived estimated cost.

OpenClaw’s Claude CLI backend runs the installed Claude Code CLI in non-interactive print mode (claude -p). Anthropic’s current Claude Code docs describe that mode as Agent SDK/programmatic usage. Anthropic’s June 15, 2026 support update paused the announced separate Agent SDK billing change: Claude Agent SDK, claude -p, and third-party app usage still draw from a signed-in subscription’s usage limits, and the previously announced monthly Agent SDK credit is not available while Anthropic revises that plan.Interactive Claude Code still draws from the signed-in Claude plan’s limits. API key auth is direct pay-as-you-go billing and does not depend on that plan. For long-lived gateway hosts, shared automation, and predictable production spend, use an Anthropic API key.Anthropic’s current support articles can change this behavior without an OpenClaw release:

Getting started

API key
Claude CLI

Best for: standard API access and usage-based billing.

Get your API key

Create an API key in the Anthropic Console.

Run onboarding

openclaw onboard
# choose: Anthropic API key

Or pass the key directly:

openclaw onboard --anthropic-api-key "$ANTHROPIC_API_KEY"

Verify the model is available

openclaw models list --provider anthropic

Config example

{
  env: { ANTHROPIC_API_KEY: "example-anthropic-key-not-real" },
  agents: { defaults: { model: { primary: "anthropic/claude-opus-4-8" } } },
}

Best for: reusing an existing Claude CLI login without a separate API key.

Ensure Claude CLI is installed and logged in

Verify with:

claude --version

Run onboarding

openclaw onboard
# choose: Claude CLI

OpenClaw detects and reuses the existing Claude CLI credentials.

Verify the model is available

openclaw models list --provider anthropic

Setup and runtime details for the Claude CLI backend are in CLI Backends.

Claude CLI reuse expects the OpenClaw process to run on the same host as the Claude CLI login. Docker installs can persist a container home and log in to Claude Code there; see Claude CLI backend in Docker. Other container installs such as Podman do not mount host ~/.claude into setup or runtime; use an Anthropic API key there, or choose a provider with OpenClaw-managed OAuth such as OpenAI Codex.

Config example

Prefer the canonical Anthropic model ref plus a CLI runtime override:

{
  agents: {
    defaults: {
      model: { primary: "anthropic/claude-opus-4-8" },
      models: {
        "anthropic/claude-opus-4-8": {
          agentRuntime: { id: "claude-cli" },
        },
      },
    },
  },
}

Legacy claude-cli/claude-opus-4-7 model refs still work for compatibility, but new config should keep provider/model selection as anthropic/* and put the execution backend in provider/model runtime policy.

Billing and `claude -p`

OpenClaw uses Claude Code’s non-interactive claude -p path for Claude CLI runs. Anthropic currently treats that path as Agent SDK/programmatic usage:

Anthropic’s June 15, 2026 support update paused the previously announced separate Agent SDK credit plan.
Subscription-plan Claude Agent SDK, claude -p, and third-party app usage still draw from the signed-in subscription’s usage limits.
The previously announced monthly Agent SDK credit is not available while Anthropic revises that plan.
Console/API-key logins use pay-as-you-go API billing and do not receive the subscription Agent SDK credit.

See Anthropic’s Agent SDK plan article for the pause notice, and the Claude Code plan articles for Pro/Max and Team/Enterprise subscription behavior.Anthropic can change Claude Code billing and rate-limit behavior without an OpenClaw release. Check claude auth status, /status, and Anthropic’s linked docs when billing predictability matters.

For shared production automation, use an Anthropic API key instead of Claude CLI. OpenClaw also supports subscription-style options from OpenAI Codex, Qwen Cloud, MiniMax, and Z.AI / GLM.

Thinking defaults (Claude Sonnet 5, Mythos 5, Fable 5, 4.8, and 4.6)

anthropic/claude-sonnet-5 uses adaptive thinking at high effort by default. Use /think off to disable thinking, or /think xhigh|max for the model’s higher native effort levels. OpenClaw omits manual thinking budgets, custom sampling parameters, assistant prefills, and Priority Tier for Sonnet 5 because Anthropic does not support those request features on this model. The catalog uses Anthropic’s introductory $2/$10 input/output pricing through August 31, 2026; standard $3/$15 pricing begins September 1, 2026. anthropic/claude-fable-5 always uses adaptive thinking and defaults to high effort. Anthropic does not allow thinking to be disabled for this model, so /think off and /think minimal map to low effort instead. OpenClaw also omits custom temperature values for Fable 5 requests, since Anthropic rejects a temperature override on any thinking-enabled request. anthropic/claude-mythos-5 is a limited-access model with the same always-on adaptive-thinking contract. OpenClaw defaults to high, maps /think off and /think minimal to low, and omits caller-selected sampling parameters. The catalog publishes its 1,000,000-token context window, 128,000-token output limit, image input, and $10/$50 input/output pricing. Claude Opus 4.8 keeps thinking off by default in OpenClaw. When you explicitly enable adaptive thinking with /think high|xhigh|max, OpenClaw sends Anthropic’s Opus 4.8 effort values; Claude 4.6 models (Opus 4.6 and Sonnet 4.6) default to adaptive. Override per-message with /think:<level> or in model params:

{
  agents: {
    defaults: {
      models: {
        "anthropic/claude-opus-4-8": {
          params: { thinking: "high" },
        },
      },
    },
  },
}

Related Anthropic docs:

Safety refusal fallback (Claude Fable 5)

Using Claude Fable 5 means also using Claude Opus 4.8. Fable 5 ships with safety classifiers that can decline a request, and Anthropic’s sanctioned recovery is to have claude-opus-4-8 serve that turn. OpenClaw opts into this automatically for direct API-key requests, so some Fable turns are answered and billed as Claude Opus 4.8. If your policy or budget cannot accept Opus-served turns, do not select anthropic/claude-fable-5.

Why this exists

Fable 5 classifiers return stop_reason: "refusal" on requests in restricted domains, and they also false-positive on benign-adjacent work (security tooling, life sciences, or even asking the model to reproduce its raw reasoning). Without a fallback, the turn dies with an error even though another Claude model would happily serve it - Anthropic’s own refusal message tells API integrators to configure a fallback model.

How it works

For every direct API-key request to anthropic/claude-fable-5, OpenClaw sends Anthropic’s server-side fallback opt-in: the server-side-fallback-2026-06-01 beta header plus fallbacks: [{"model": "claude-opus-4-8"}]. Claude Opus 4.8 is the only fallback target Anthropic permits for Fable 5.
Only a safety-classifier decline triggers the fallback. Rate limits, overloads, and server errors behave exactly as before and go through OpenClaw’s normal model failover.
The rescue happens inside the same call. A decline before any output is invisible apart from latency; the whole answer comes from Opus 4.8. On a mid-stream decline the partial text is kept as the prefix the fallback model continues from, while the declined model’s reasoning and tool calls are discarded per Anthropic’s replay rules (they must not be echoed back or executed).
If Claude Opus 4.8 declines as well, the turn surfaces the refusal as an error, exactly like before this feature.

The fallback happens at the Anthropic API level, so claude-opus-4-8 does not need to be in your configured model list or fallback chain - a Fable-capable API key can always serve Opus.

Observability and billing

A fallback-served turn records a provider_fallback diagnostic on the assistant message naming fromModel and toModel, and the message’s responseModel reports claude-opus-4-8.
Anthropic bills per attempt: a decline before output is free, and the rescue bills at Claude Opus 4.8 rates (currently half of Fable 5 rates). OpenClaw’s per-turn cost estimate prices fallback-served turns at Opus rates to match.
A mid-stream decline additionally bills the already-streamed Fable partial on Anthropic’s side; that portion is reported in the API’s per-attempt usage but not folded into OpenClaw’s per-turn estimate.

Scope

Applies to anthropic/claude-fable-5 with API-key auth against api.anthropic.com. OAuth (Claude CLI subscription reuse), proxy base URLs, Bedrock, Vertex, and Foundry requests are unchanged and still surface refusals as errors there. Verified live: a benign prompt asking Fable 5 to reproduce its raw chain of thought is declined with category: "reasoning_extraction" when sent without fallbacks, and the same prompt through OpenClaw returns a normal Opus-served answer with the provider_fallback diagnostic attached. See Anthropic’s refusals and fallback guide for the underlying behavior.

Prompt caching

OpenClaw supports Anthropic’s prompt caching feature for API-key auth.

Value	Cache duration	Description
`"short"` (default)	5 minutes	Applied automatically for API-key auth
`"long"`	1 hour	Extended cache
`"none"`	No caching	Disable prompt caching

{
  agents: {
    defaults: {
      models: {
        "anthropic/claude-opus-4-6": {
          params: { cacheRetention: "long" },
        },
      },
    },
  },
}

Per-agent cache overrides

Use model-level params as your baseline, then override specific agents via agents.list[].params:

{
  agents: {
    defaults: {
      model: { primary: "anthropic/claude-opus-4-6" },
      models: {
        "anthropic/claude-opus-4-6": {
          params: { cacheRetention: "long" },
        },
      },
    },
    list: [
      { id: "research", default: true },
      { id: "alerts", params: { cacheRetention: "none" } },
    ],
  },
}

Config merge order:

agents.defaults.models["provider/model"].params
agents.list[].params (matching id, overrides by key)

This lets one agent keep a long-lived cache while another agent on the same model disables caching for bursty/low-reuse traffic.

Bedrock Claude notes

Anthropic Claude models on Bedrock (amazon-bedrock/*anthropic.claude*) accept cacheRetention pass-through when configured.
Non-Anthropic Bedrock models are forced to cacheRetention: "none" at runtime.
API-key smart defaults also seed cacheRetention: "short" for Claude-on-Bedrock refs when no explicit value is set.

Advanced configuration

Fast mode

OpenClaw’s shared /fast toggle sets Anthropic’s service_tier field for direct API-key traffic to api.anthropic.com.

Command	Maps to
`/fast on`	`service_tier: "auto"`
`/fast off`	`service_tier: "standard_only"`

{
  agents: {
    defaults: {
      models: {
        "anthropic/claude-sonnet-4-6": {
          params: { fastMode: true },
        },
      },
    },
  },
}

Only applies to direct api.anthropic.com requests made with an API key. OAuth/subscription-token requests and proxy routes never get a service_tier field.
Explicit serviceTier or service_tier params override /fast when both are set.
On accounts without Priority Tier capacity, service_tier: "auto" may resolve to standard.

Media understanding (image and PDF)

The bundled Anthropic plugin registers image and PDF understanding. OpenClaw auto-resolves media capabilities from the configured Anthropic auth; no additional config is needed.

Property	Value
Default model	`claude-opus-4-8`
Supported input	Images, PDF documents

When an image or PDF is attached to a conversation, OpenClaw automatically routes it through the Anthropic media understanding provider.

1M context window

Claude Sonnet 5, Mythos 5, and Fable 5 have an exact 1,000,000-token input window and support up to 128,000 output tokens. Anthropic’s 1M context window is also GA on Claude 4.x models with adaptive thinking: Opus 4.8, Opus 4.7, Opus 4.6, and Sonnet 4.6. OpenClaw sizes these models automatically, no params.context1m needed:

{
  agents: {
    defaults: {
      models: {
        "anthropic/claude-sonnet-5": {},
        "anthropic/claude-mythos-5": {},
        "anthropic/claude-opus-4-6": {},
      },
    },
  },
}

Older configs can keep params.context1m: true; it is a harmless no-op for these models and OpenClaw no longer sends the retired context-1m-2025-08-07 beta header regardless. Older anthropicBeta config entries with that value are dropped during request header resolution, and unsupported older Claude models stay on their normal context window.params.context1m: true behaves the same way for the Claude CLI backend (claude-cli/*): eligible GA-capable Opus and Sonnet models already get the 1M window automatically, so the param is optional there too.

Requires long-context access on your Anthropic credential. OAuth/subscription token auth keeps its required Anthropic beta headers, but OpenClaw strips the retired 1M beta header if it remains in older config.

Claude Opus 4.8 1M context

anthropic/claude-opus-4-8 and its claude-cli variant have a 1M context window by default; no params.context1m: true needed.

Troubleshooting

401 errors / token suddenly invalid

Anthropic token auth expires and can be revoked. For new setups, use an Anthropic API key instead.

No API key found for provider "anthropic"

Anthropic auth is per agent; new agents do not inherit the main agent’s keys. Re-run onboarding for that agent (or configure an API key on the gateway host), then verify with openclaw models status.

No credentials found for profile "anthropic:default"

Run openclaw models status to see which auth profile is active. Re-run onboarding, or configure an API key for that profile path.

No available auth profile (all in cooldown)

Check openclaw models status --json for auth.unusableProfiles. Anthropic rate-limit cooldowns can be model-scoped, so a sibling Anthropic model may still be usable. Add another Anthropic profile or wait for cooldown.

More help: Troubleshooting and FAQ.

Model selection

Choosing providers, model refs, and failover behavior.

CLI backends

Claude CLI backend setup and runtime details.

Prompt caching

How prompt caching works across providers.

OAuth and auth

Auth details and credential reuse rules.

​Usage and cost tracking

​Getting started

​Config example

​Config example

​Billing and claude -p

​Thinking defaults (Claude Sonnet 5, Mythos 5, Fable 5, 4.8, and 4.6)

​Safety refusal fallback (Claude Fable 5)

​Why this exists

​How it works

​Observability and billing

​Scope

​Prompt caching

​Advanced configuration

​Troubleshooting

​Related

Model selection

CLI backends

Prompt caching

OAuth and auth

Usage and cost tracking

Getting started

Config example

Config example

Billing and `claude -p`

Thinking defaults (Claude Sonnet 5, Mythos 5, Fable 5, 4.8, and 4.6)

Safety refusal fallback (Claude Fable 5)

Why this exists

How it works

Observability and billing

Scope

Prompt caching

Advanced configuration

Troubleshooting

Related