Zambo

Zambo's free tier provides 20 calls per tool per day with no registration required, and is compatible with Claude, ChatGPT, Gemini, Cursor, Windsurf, and any agent that supports the MCP protocol.

The article is essentially promotional in nature, centered on Zambo/AER-1, and mentions pricing information such as a $0.99 day pass.

The receipt mechanism provides corresponding installation packages for mainstream frameworks, such as pip install crewai-zambo for CrewAI, pip install langchain-zambo for LangChain, pip install aer1-openai-agents for OpenAI Agents, and npm install aer-1 for the Node ecosystem.

Zambo is positioned as an evidence layer for auditing and accountability rather than a judgment layer for quality control, and its value is significant in scenarios that require after-the-fact traceability, such as compliance, auditing, and multi-party collaboration.

Zambo's capability boundary is ensuring the evidence chain has not been tampered with, not ensuring decisions are error-free; even if an agent performs an incorrect operation, Zambo will still generate a complete receipt for that incorrect operation.

Zambo's free tier allows 20 calls per tool per day with no account or API key required; for higher-frequency use, a $0.99 day pass can be purchased to enable unlimited receipt generation within a single day.

Zambo's verification process is: copy the receipt ID, paste it on the verification page at https://zambo.dev/verify/, the verifier recomputes the SHA-256 hash, and a match indicates the result has not been altered.

Zambo positions itself as a universal verification layer spanning multiple frameworks rather than a plugin tied to a single ecosystem, and provides independent components such as the aer1kit core suite, the aer1-verify verifier, and the aer1-middleware middleware.

Zambo provides installation packages covering multiple agent frameworks, including LangChain (langchain-zambo), CrewAI (crewai-zambo), OpenAI Agents, Agno, LlamaIndex, AutoGen, and Pydantic.

Clients that support MCP (such as Claude, ChatGPT, Cursor, Windsurf, and VS Code) can connect to Zambo simply by copying and pasting the MCP URL https://zambo.dev/mcp.

Zambo provides a Grok bot that allows users to ask it to prove something on X and receive a shareable, retweetable receipt.

Zambo offers an installation-free demo: visit the official demo page, click a button, and receive a real execution receipt in approximately 10 seconds, with no registration, API key, or installation required.

Zambo verifies the execution behavior itself—recording what ran, the inputs and outputs, and the runtime—but does not guarantee the correctness of the answer; it only proves that the record has not been tampered with since it was saved.

Zambo generates a verifiable execution receipt for every tool call made by an AI agent, binding the execution evidence together with a SHA-256 hash for independent verification.

Zambo claims to be compatible with any AI, including Claude, ChatGPT, Gemini, Cursor, Windsurf, and any agent framework capable of calling tools via MCP.

Zambo is a verification tool for AI agent work, designed with the philosophy of receipt-by-default, where every call made through Zambo automatically returns a verifiable receipt.

Zambo's receipt can only prove that the saved result has not been altered since it was saved, and cannot prove that the answer itself is correct.

The entire verification and checking process reportedly takes only about 30 seconds, and anyone holding a receipt ID can run the check without registration or special permissions.

The author recommends verifying execution with receipts and verifying correctness through consistent methods such as cross-checking key numbers.

The tamper-proof mechanism of hash receipts is the underlying principle behind blockchain's tamper-proof capability, and Zambo ports it in a lightweight manner to agent invocation scenarios.