Glossary

Glossary

Words this project uses with a fixed meaning. When a term is overloaded upstream, the PiCode sense is the one below.

Term	Meaning in PiCode
Host	The agent that executes: Pi. PiCode ships an internal one; connecting to an external one is optional. Vocabulary fixed by the owner.
Harness	The layer organizing work above the host: Gentle AI (gentle-pi package + gentle-ai Go CLI). Also internal by default.
Pin	The exact upstream version the tree is verified against: upstream/stable.json records the VS Code commit picode-source/ descends from. It moves by hand, via a merge — see Building PiCode.
Product delta	distribution/product-delta.json — the only source of PiCode's product identity (including the version): set, unset, unsetNested, unsetArrayEntries. Data, applied to picode-source/product.json by distribution/apply-product-delta.mjs in phase 1 of the build.
Source tree	picode-source/ — PiCode's own source: the VS Code-derived editor with every PiCode change committed as code, versioned in the repository. Nothing is downloaded and nothing is applied; a newer VS Code arrives as a merge against this tree.
Portable profile	The data/ folder beside the executable: user data, extensions, tmp, and the Pi profile. Disposable; the future cloud-sync unit.
Connector	The built-in core extension extensions/picode (compiled by phase 2 of the build): pi's model provider, the @pi participant, MCP tools, profile import, themes. Draws no UI of its own — that is the rule.
Agent host	The core process slot (src/vs/platform/agentHost/) where VS Code puts its agents; Pi enters it as an IAgent provider.
RPC mode	pi --mode rpc: JSONL over stdio, LF-only framing, delta events assembled client-side, usage per message not total.
Managed runtime	Pi installed by PiCode into resources/pi-runtime, pinned version, invoked as node …/cli.js (no .cmd shim — CVE-2024-27980 hardening).
ODD	Organic Driven Development — Gentle AI's default workflow: authorize, explore, resolve uncertainty, classify, track, implement task by task, close. SDD is a branch inside ODD, entered by explicit request.
SDD / OpenSpec	The spec-driven branch: proposal → spec → design → tasks → apply → verify → archive, with phase artifacts and agents.
Engram	Gentle's persistent-memory companion package (gentle-engram, mem_* tools). Not built into PiCode; a Pi package like any other.
Skills / Subagents / Prompt templates	Pi's extension formats: SKILL.md folders, .md agent files, prompts/*.md (filename becomes /command). Discovered from profile and package paths.
Work unit	One reviewable change: a commit or PR slice a human can hold in their head. The unit of both git and review discipline.
RDD / receipt	Receipt-Driven Development: Gentle AI's review lifecycle (frozen candidate, lineage, capture, acknowledgement). Its switch belongs to the user; PiCode exposes state, invents no policy.
Open VSX	The extension gallery this editor may install from; the Microsoft Marketplace is not licensed for third-party builds.
Legacy panel	The retired webview surface (extensions/picode-pi-chat): removed by the owner's decision on 2026-09-27. Its replacement is the native chat modified in the core (src/vs/workbench/contrib/chat/** plus src/vs/platform/agentHost/).

Two version numbers, on purpose

distribution/product-delta.json carries two, because they do two jobs:

• set.version — the editor's number. It keeps the VS Code shape so extensions keep installing (today 1.141.1), and it is what the updater compares. The source descends from VS Code 1.135.0; the number is bumped so extension engines that ask for ^1.x are not refused.
• set.picodeVersion — PiCode's number. It names the release (0.2.1), its tag and its download file.

What you read in the interface is PiCode's; what the updater compares is the editor's. VSCodium and Cursor do the same. The full reasoning is in odd/tasks/picode-versionado.md.

Related: What PiCode Is · Building PiCode · Decisions Log