Glossary
The acronyms of this book, spelled out, with a short explanation and the context in which they appear. In the body of the chapters, hovering over an acronym shows its meaning (abbr); here is the complete reference. The expansions were checked against the text itself (Principle I).
Agents, protocols and orchestration
- MCP — Model Context Protocol. Open protocol that standardizes how a harness plugs external tools, data and prompts into the model. Appears in: ch. 06 (MCP) and ch. 17 (Protocols).
- ACP — Agent Client Protocol. Protocol (originated at Zed) for the agent ↔ editor/client conversation. Not to be confused with IBM's Agent Communication Protocol (also "ACP"), discontinued and merged into A2A. Appears in: ch. 13 (Interfaces), ch. 17.
- MRTR — Multi Round-Trip Requests. Pattern from the MCP 2026-07-28 spec that replaces server-initiated requests (sampling/elicitation): the server responds
input_requiredand the client retries with the answers. Appears in: ch. 06. - DCR — Dynamic Client Registration. Dynamic registration of OAuth clients; deprecated in the MCP 2026-07-28 spec in favor of CIMD. Appears in: ch. 06.
- CIMD — Client ID Metadata Documents. DCR's successor in MCP authorization: the client's identity comes from a metadata document. Appears in: ch. 06.
- A2A — Agent-to-Agent. Protocol for delegation between agents (originated at Google, donated to the Linux Foundation). Appears in: ch. 10 (Subagents), ch. 17.
- LSP — Language Server Protocol. The standard that inspired agent protocols: it separates the "intelligence" (server) from the interface (client). Appears in: ch. 11, ch. 12, ch. 14.
- RPC — Remote Procedure Call. Calling a procedure in another process/machine as if it were local; the basis of several protocols. Appears in: chs. 05, 06, 10 and 12.
- MAST — Multi-Agent System Failure Taxonomy. Taxonomy of failure modes of multi-agent systems (from the paper "Why Do Multi-Agent LLM Systems Fail?"). Appears in: ch. 10 (Subagents), bibliography.
- RAG — Retrieval-Augmented Generation. Generation augmented by retrieval: fetch relevant excerpts and inject them into the context. Appears in: ch. 03 (Context), ch. 08.
Models and AI
- AI — Artificial Intelligence (in the Portuguese original, IA — Inteligência Artificial). Appears in: the whole book.
- LLM — Large Language Model. The model the harness wraps. Appears in: the whole book.
- GPT — Generative Pre-trained Transformer. A family of language models. Appears in: chs. 01, 05 and 09, bibliography.
- SWE-bench / SWE-agent — Software Engineering (benchmark / software-engineering agent). Appears in: ch. 11 (Evals).
Tools, interfaces and networking
- API — Application Programming Interface. The contract through which programs talk to each other. Appears in: the whole book.
- SDK — Software Development Kit. A kit for building on top of a platform (e.g. the Agent SDK). Appears in: ch. 12 (Extensibility), ch. 13.
- CLI — Command-Line Interface. Appears in: ch. 13.
- TUI — Text (Terminal) User Interface. Interactive text interface in the terminal. Appears in: ch. 13.
- IDE — Integrated Development Environment. (e.g. VS Code). Appears in: ch. 13.
- UI — User Interface / UX — User Experience. The user's interface and experience. Appears in: ch. 13.
- HCI — Human-Computer Interaction. (a scientific field). Appears in: ch. 13.
- HTTP — HyperText Transfer Protocol. The protocol of the web. Appears in: chs. 06, 10, 11 and 13.
- SSE — Server-Sent Events. Streaming of events from server to client (used in the chat). Appears in: ch. 13.
- JSON — JavaScript Object Notation. The data format of tool schemas. Appears in: ch. 05, 06.
- OS — Operating System (in the Portuguese original, SO — Sistema Operacional). Appears in: ch. 07 (Permissions and Sandboxing).
- CI — Continuous Integration. Appears in: ch. 11, apparatus.
- DDD — Domain-Driven Design. Guides the
harness-zero. Appears in: the hands-on build.
Editorial, publishing and research
- DOI — Digital Object Identifier. The work's persistent identifier (Zenodo). Appears in: apparatus, cover.
- ORCID — Open Researcher and Contributor ID. The researcher's identifier (the author's). Appears in: apparatus, "About the author".
- ISBN — International Standard Book Number. The standard identifier for books. Appears in: Editorial Guide.
- CC — Creative Commons. A family of open licenses (the content is CC BY 4.0). Appears in: license, apparatus.
- MIT. Permissive software license (the name comes from the Massachusetts Institute of Technology); covers the code. Appears in: license.
- ICMJE — International Committee of Medical Journal Editors and COPE — Committee on Publication Ethics. Authorship/ethics guidelines followed in disclosing AI co-authorship. Appears in: Editorial Guide §6.
- ICLR — International Conference on Learning Representations. Scientific conference cited in the bibliography. Appears in: bibliography.