Anthropic

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.

Getting started

openclaw onboard# choose: Anthropic API key

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

openclaw models list --provider anthropic

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

claude --version

openclaw onboard# choose: Claude CLI

openclaw models list --provider anthropic

openclaw models auth login --provider anthropic --method setup-token

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

Claude sessions across computers

The bundled Anthropic plugin adds a Claude Code group to the normal sessions sidebar. Rows open in the normal Chat pane. It discovers non-archived Claude Code sessions on the Gateway and on connected node hosts:

• Claude CLI sessions come from valid project-index records and current JSONL files whose bounded metadata prefix identifies a non-sidechain sdk-cli session under ~/.claude/projects/.
• Claude Desktop sessions use the Desktop title, activity time, and archive state when its metadata points to the same Claude Code session ID.
• A CLI-only session has no archive flag, so it remains visible while its transcript is present.

No additional OpenClaw config is required for discovery. The Anthropic plugin is bundled and enabled by default; a native macOS node advertises the read-only Claude session commands when the local ~/.claude/projects/ directory exists. Approve the node pairing upgrade when those commands first appear.

The sidebar groups rows by their Gateway or paired-node host, starts with the newest bounded page from each host, and refreshes on the normal 30-second cadence. Use Load more sessions below a catalog group to append the next page for every host that has more history; appended rows stay visible and are re-fetched to the same depth across refreshes. Catalog clients use sessions.catalog.list; opening a row uses sessions.catalog.read.

Terminal takeover resolves claude from the owning host user's login-shell PATH before the service/daemon PATH. This keeps app-launched sessions aligned with the Claude CLI the operator gets in a normal terminal.

Selecting a row reads the newest transcript page first. Load older transcript items follows an opaque byte cursor and reads another bounded section from the JSONL file instead of loading the entire history. Normal user, assistant, reasoning, tool-call, and tool-result content is preserved. An individual item larger than the node/Gateway safety ceiling is clearly marked as truncated.

For a Gateway-local claude-cli row, typing in the normal composer calls sessions.catalog.continue. OpenClaw re-resolves the local catalog record, creates or reuses a model-locked native session, imports at most 200 visible items or 512 KiB, and seeds the Claude CLI binding. The first turn resumes with --fork-session; Claude assigns the fork a new session ID, so later turns use the fork and the source session stays untouched.

A headless node host can also make its Claude CLI rows continuable by enabling the node-local setting below and restarting the node host:

{  nodeHost: {    agentRuns: {      claude: { enabled: true },    },  },}

The node advertises agent.cli.claude.run.v1 only when the setting is enabled and its local claude executable resolves. OpenClaw re-resolves the catalog record on that node, imports the same bounded history, and binds the adopted session to the node and catalog-reported working directory. Each turn runs the node's real claude -p process using that node's Claude files and login. The node's exec approval policy still applies; the Gateway cannot force the opt-in.

Node continuation v1 is one-shot only. It omits Gateway loopback MCP config and Gateway skills plugin arguments, does not reseed from a Gateway transcript, and rejects attachments and images. Claude Desktop rows remain view-only. Native macOS app nodes also remain view-only until the app advertises the run command.

See Nodes: Claude sessions and transcripts for the node command and security boundary.

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" },        },      },    },  },}

Safety refusal fallback (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

1. 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.
2. 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.
3. 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).
4. 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.

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

{  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" } },    ],  },}

Advanced configuration

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

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

Troubleshooting

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