zambo-smolagents

Verifiable execution receipts for smolagents agents. Give your smolagents agent Zambo's 100+ live tools. Every tool call is executed by Zambo and mints a verifiable AER-1 receipt: a public URL carrying the tool, its arguments, the observed result, a SHA-256 fingerprint, and machine-readable JSON-LD.

from smolagents import CodeAgent, InferenceClientModel
from zambo_smolagents import zambo_tools

agent = CodeAgent(
    tools=zambo_tools(["live_price", "prompt_shield"]),
    model=InferenceClientModel(),
)
agent.run("What is the live BTC price?")

No account. No API key. Free tier: 20 calls per tool per day.

What the receipt actually proves

Each receipt page (for example https://zambo.dev/run/<id>) is Zambo's tamper-evident record that Zambo executed the tool call itself: the tool name, the exact arguments your agent sent, the observed result, a timestamp, and a SHA-256 fingerprint of the record, published as JSON-LD. Anyone can re-verify it with no account.

Every tool's output ends with the receipt URL (Verifiable receipt: https://zambo.dev/run/<id>), so the agent's trajectory shows proof next to every call. You can also collect receipts programmatically:

from zambo_smolagents import zambo_tool

receipts = {}
tool = zambo_tool("live_price", on_receipt=lambda name, url: receipts.setdefault(name, []).append(url))
print(tool(arguments_json='{"symbol": "BTC"}'))
print(receipts)

Install

pip install zambo-smolagents

One tool, custom inputs

from zambo_smolagents import zambo_tool

price_tool = zambo_tool(
    "live_price",
    inputs={
        "symbol": {"type": "string", "description": "Asset symbol, e.g. BTC."},
    },
)
print(price_tool(symbol="BTC"))

Browse the full catalog any time with zambo_smolagents.list_tools(), or pick tools by use case through Zambo's capability_search tool.

Notes

• Zambo calls need no key and no signup. Heavy runs (dozens of tool calls) will reach the free daily limit; the tool raises a clear error and the agent run continues with the other tools.
• Receipts are public by design. Do not pass secrets as tool arguments.
• The client is pure stdlib (urllib) with retries: smolagents is the only third-party dependency.

Links

• Zambo: https://zambo.dev
• AER-1 receipt spec: https://zambo.dev/aer-1/
• Framework agent execution receipts: https://zambo.dev/guides/framework-agent-execution-receipts/
• What is an AI agent execution receipt?: https://zambo.dev/guides/ai-agent-execution-receipt/

MIT License.

Local AER-1 receipts (no network needed)

The package also mints AER-1 execution receipts locally, with no API calls:

from zambo_smolagents import mint_receipt, verify_receipt

receipt = mint_receipt("my_tool", {"query": "hello"}, {"answer": "hi"}, ms=42)
assert verify_receipt(receipt)  # recomputes the SHA-256 locally

Local receipts follow the AER-1 core members (id, created_at, tool, provenance_class, canonical_bytes, output_hash) and use the provenance class EXECUTED BY ZAMBO-SMOLAGENTS, naming this package as the recording system. They pass the same hash-recomputation check as any AER-1 receipt.