Claude Agent SDK / Claude Code

​

Install

pip install "decimalai[claude-agent-sdk]"

​

Trace every run

import asyncio

import decimalai
decimalai.init(api_key="dai_sk_...", claude_agent_sdk=True)

# Every query() stream is now traced automatically
from claude_agent_sdk import query, ClaudeAgentOptions


async def main():
    async for message in query(prompt="Fix the bug", options=ClaudeAgentOptions()):
        print(message)


asyncio.run(main())   # one query() run to completion = one trace

​

Explicit form — wrap a stream you already have

import asyncio

import decimalai
decimalai.init(api_key="dai_sk_...")   # no claude_agent_sdk=True: nothing is patched

from decimalai.claude_agent_sdk import trace_stream
from claude_agent_sdk import query, ClaudeAgentOptions

options = ClaudeAgentOptions(system_prompt="You are a support agent.")


async def main():
    async for message in trace_stream(
        query(prompt="Refund order 4512", options=options),
        agent_name="support",
        user_input="Refund order 4512",
        options=options,   # read for manifest extraction
    ):
        print(message)


asyncio.run(main())

​

What gets captured

• One trace per query() run: every assistant turn as an LLM call, tool calls matched to their results (with latency and per-tool error status)
• Cumulative token usage and cost from the final ResultMessage, including cache-read/creation input tokens
• Auto-detected manifest from ClaudeAgentOptions + the init message: model, system prompt, allowed tools (names), and subagents
• Run status: a failed tool doesn’t fail the run — the ResultMessage is authoritative
• Skills Claude Code loads from your installed skills, as activations with their version (SDK 0.16.0+; see Skills)

​

Skills: Claude Code loads them from disk

decimalai skills add acme/refund-policy    # writes .agents/skills/acme-refund-policy/

​

Load installed skills as a Claude Code plugin

import asyncio

import decimalai
decimalai.init(api_key="dai_sk_...", claude_agent_sdk=True)

from claude_agent_sdk import ClaudeAgentOptions, query
from decimalai.claude_agent_sdk import skills_plugin

options = ClaudeAgentOptions(
    plugins=[skills_plugin()],   # the project's .agents/, the plugin root, as an absolute path
    skills="all",   # the Agent SDK's own switch for the Skill tool
)


async def main():
    async for message in query(prompt="Refund order 4512", options=options):
        print(message)


asyncio.run(main())

claude --plugin-dir "$(git rev-parse --show-toplevel)/.agents"

• Each load is an activation (SDK 0.16.0+). With the stream traced (init(claude_agent_sdk=True) or trace_stream), each skill body the CLI hands the model is recorded as an activation carrying its version, and the DecimalAI skills in the CLI’s skill catalog as offered. The frontmatter never reaches your process, so the version comes from the lock, by the hash of the delivered body. After decimalai skills update, Claude Code serves the new version.
• Skill names carry the plugin’s prefix. Claude Code lists the skills as decimalai-skills:acme-refund-policy. The plugin is not called decimalai because the marketplace plugin already has that name, and two plugins with one name replace each other.
• Only skills your org wrote pre-approve tools. While a skill is active, Claude Code runs the tools its allowed-tools lists without asking. The registry keeps that list whole only for a skill your org wrote itself; for any other, a fork or an import included, it keeps only Read, Grep and Glob, so running that skill’s scripts needs your permission.
• On-demand skills stay on demand. A skill the registry marks on-demand carries disable-model-invocation: true. Claude Code lists it but runs it only when you invoke it; of the native loaders, only Claude Code and the Pydantic AI harness honour that key.

​

Caveats

• DECIMAL_AUTO_TRACE has no claude-agent-sdk value — use init(claude_agent_sdk=True) in code.
• Tool schema depth in the manifest is names only (allowed_tools is a name list). Use register_manifest() if you need schema-aware regression checks.
• This adapter is distinct from decimalai.anthropic (agent_config() for the raw Messages API) and from init(anthropic=True) (raw provider tracing). The Claude Agent SDK is Anthropic-native; pair it with the anthropic provider only.

​

What’s next