Anthropic

Advisor tool (secondary-model advisor) beta header.

Agent persistent memory beta header (Memory Stores API).

Beta header constants

User management (CE) beta header for Organization endpoints.

Context compaction revision (signed compaction blocks).

Context compaction beta header.

Computer-use toolset revision (November 2025).

1M context window beta header.

Extended / interleaved thinking betas.

Dreams (memory consolidation) beta header.

Research-preview API: request/response shapes may change without a deprecation period. Required by client.beta.dreams.* together with MANAGED_AGENTS_BETA (both auto-attached). Access is separately gated.

Primary fallback-credit beta. Tracks the latest official default (July 2026).

Fallback-credit beta header (June 2026). Kept for callers that pin the older bare-string credit-token behavior.

Fallback-credit beta header (July 2026) — required for object-form fallback_credit_token ({token, mode}) and used by default by BetaRefusalFallbackMiddleware.

Only valid string form of fallbacks (server-defined default chain).

Fast mode beta header.

Inline tool definitions beta header.

MCP client revision with tool-list pinning.

MCP Tunnels beta header (research preview).

Required by client.beta.tunnels.* and client.beta.tunnels.certificates.*. Supersedes Admin API /v1/organizations/tunnels during a migration window. Management calls need WIF with workspace:manage_tunnels — not API keys.

Mid-conversation output-config changes beta header.

Mid-conversation system clear_at beta header.

Mid-conversation tool changes beta header.

Surfaces model_context_window_exceeded as a recoverable stop_reason.

Shorthand helper for accessing model IDs via symbols

Anthropic::Model::CLAUDE_SONNET # => "claude-sonnet-5"
Anthropic::Model::CLAUDE_FABLE  # => "claude-fable-5"
Anthropic::Model::CLAUDE_OPUS   # => "claude-opus-5"
Anthropic::Model::CLAUDE_HAIKU  # => "claude-haiku-4-5"

Anthropic.model_name(:sonnet) # => "claude-sonnet-5"
Anthropic.model_name(:fable)  # => "claude-fable-5"
Anthropic.model_name(:mythos) # => "claude-mythos-5"
Anthropic.model_name(:opus)   # => "claude-opus-5"
Anthropic.model_name(:opus_5) # => "claude-opus-5"
Anthropic.model_name(:haiku)  # => "claude-haiku-4-5-20251001"

Output token cap betas.

PDF document support beta header.

Primary server-side fallbacks beta. Tracks the latest official default (July 2026). Auto-attached when fallbacks: is set.

Server-side fallbacks beta header (June 2026).

Prefer SERVER_SIDE_FALLBACK_BETA / SERVER_SIDE_FALLBACK_BETA_2026_07_01 for new code; this constant is kept for callers that pin the older header.

Server-side fallbacks beta header (July 2026) — supports fallbacks: "default" and aligns with the official Python/Ruby/TS SDKs.

Task budgets beta header (session/task spend ceilings).

Thinking binding controls beta header.

Thinking display mode updates for enabled/adaptive thinking configs.

Thinking token count in streaming deltas (optional display).

Latest user-profiles revision. Kept alongside USER_PROFILES_BETA (2026-03-24, still the resource default) for callers that pin newer behavior such as order_by listing support.

User-profiles revision with external_user_details support.

User profiles beta header.

Request header identifying the worker polling a self-hosted environment work queue.

Request header selecting the Workspace a request runs under.

Collect the beta header strings required by a set of server tools.

This is the single source of truth for server-tool-to-beta mappings so that resource classes don't have to duplicate the case logic.

Returns true when fallbacks is a non-empty chain or the string "default".

Any other string (including empty) is treated as absent so we do not auto-attach the server-side fallback beta for typos like "defaults". Serialization via FallbacksParamConverter also rejects non-"default" strings with ArgumentError.

Merge an anthropic-workspace-id request header into an existing header hash. Centralized so every resource sets the header the same way; nil leaves the headers untouched.

Convenience method to create an output schema

output = Anthropic.output_schema(
  name: "weather_report",
  schema: {
    "temperature" => Schema.number("Current temperature"),
    "conditions"  => Schema.string("Weather conditions"),
  },
  required: ["temperature", "conditions"]
)

Resolve and compile the complete "anthropic-beta" headers mapping

Helper method for creating inline tools with Schema DSL

weather_tool = Anthropic.tool(
  name: "get_weather",
  description: "Get current weather for a location",
  schema: {
    "location" => Schema.string("City name, e.g. San Francisco, CA"),
    "unit"     => Schema.enum("celsius", "fahrenheit", description: "Temperature unit"),
  },
  required: ["location"]
) do |input|
  location = input["location"].as_s
  unit = input["unit"]?.try(&.as_s) || "fahrenheit"
  "The weather in #{location} is sunny and 72°#{unit == "celsius" ? "C" : "F"}."
end

Macro to create a typed output schema from a struct

struct MyOutput
  include JSON::Serializable
  getter result : String
  getter confidence : Float64
end

schema = Anthropic.output_schema(type: MyOutput, name: "my_output")

Macro to create typed tools with struct input

This provides Ruby BaseTool-like functionality where:

• Input schema is derived from a Crystal struct
• Handler receives typed struct instead of JSON::Any
• Field descriptions come from @[JSON::Field(description: "...")]

struct SearchInput
  include JSON::Serializable
  getter query : String
  getter category : Category?
end

tool = Anthropic.tool(
  name: "search",
  description: "Search products",
  input: SearchInput
) do |input|
  "Found results for #{input.query}"
end