Lore

The story of how cli/cli evolved, derived from git history (2019-10-03 to 2026-04-30, 11,228 commits on trunk).

Eras

The bootstrap (Oct 2019 - Feb 2020)

The repo opens with a single commit on 2019-10-03 from the GitHub team. CI lands the next morning, and within weeks gh issue and gh pr start to take shape. This era was conducted under the working name gh and was originally introduced as a successor to the long-running hub project. The early architecture (cmd/gh, pkg/cmd/<command>, an api/ package) is recognizably the same one used today.

Public beta and 1.0 (Feb 2020 - Sep 2020)

gh ships its first public beta in early 2020 and reaches v1.0 by autumn. The boundaries of pkg/cmd/issue/, pkg/cmd/pr/, pkg/cmd/repo/, pkg/cmd/auth/, and pkg/cmd/release/ are settled. The cmdutil.Factory pattern is established as the standard way to wire dependencies into commands. pkg/iostreams/ and pkg/httpmock/ solidify as the cross-cutting infrastructure.

The Codespaces integration (Apr 2021 - 2022)

GitHub Codespaces ships as a public product, and a substantial chunk of its CLI lives directly in cli/cli. The pkg/cmd/codespace/ and internal/codespaces/ trees are added with their own SSH, port-forwarding, and Live Share RPC clients. Today this is still one of the largest single subsystems by line count (internal/codespaces/api/api.go alone is ~37 KB).

Extensions and the platform years (2022 - 2023)

gh extension matures into a real package manager: precompiled binaries (2022), Go-source-tree extensions, and the "official extension stub" mechanism that gently nudges users toward GitHub-owned extensions when they invoke unrecognized commands. A search index (gh extension search), browse (gh extension browse), and a moq-based test mock (pkg/cmd/extension/mocks.go) all land here.

Attestation (early 2024)

A new pkg/cmd/attestation/ tree appears in early 2024 and grows quickly. It vendors a Sigstore + TUF verification stack (pkg/cmd/attestation/verification/, pkg/cmd/attestation/trustedroot/) and embeds an offline copy of the GitHub Sigstore trusted-root under pkg/cmd/attestation/verification/embed/tuf-repo.github.com/. From the same milestone, every gh release is itself signed and verifiable with gh at verify.

The agent and skills era (2025 - 2026)

The two most active areas of recent development:

• AI agent detection (added across 2025): internal/agents/detect.go recognizes Codex, Claude Code, Copilot CLI, Gemini CLI, Amp, and OpenCode from environment variables and propagates the result into the API user agent. This pre-dates gh skill and is reused by it.
• Skills (pkg/cmd/skills/, internal/skills/, started ~mid-2025): a full subsystem with install, update, publish, preview, and search subcommands, plus an installer, a registry client, a discovery layer, a frontmatter parser, and a lockfile. As of April 2026, skills dominates the 90-day churn list (78 commits in internal/skills/, 18 in pkg/cmd/skills/install/install.go alone).
• gh agent-task (added in this same window): a top-level command tree under pkg/cmd/agent-task/ for orchestrating long-running AI tasks against a repository.
• gh accessibility and gh copilot also land in this era as first-party commands.

Longest-standing features

Feature	First seen	Notes
Cobra root + cmd/gh/main.go boot path	2019-10	The 4-step main -> ghcmd.Main -> root.NewCmdRoot -> Execute flow has been stable since v1.0.
pkg/cmd/issue/list/list.go	2020-08	Has been the canonical example of "the right way to write a gh command" since 2020.
pkg/iostreams/iostreams.go	2019 / early 2020	The TTY/color/pager abstraction has changed signatures rarely; new fields are added but the interface is stable.
api/queries_repo.go	2019 / early 2020	Now ~46 KB; it has accreted queries continuously and remains the central place to add repository-related GraphQL/REST calls.
pkg/httpmock/	2019	The mock has been the testing primitive for HTTP since the project started.

Deprecated and replaced surfaces

• context/: marked DEPRECATED in docs/project-layout.md. New code only uses it for the legacy Remotes type.
• test/ and utils/: also marked DEPRECATED. utils/ survives as the home of "print a table" helpers that have not yet been migrated to internal/tableprinter.
• gh secret v1 schema: replaced by the unified secrets handler in pkg/cmd/secret/shared once Actions, Codespaces, and Dependabot secrets converged.
• Old prompter: the project migrated from raw survey/v2 calls scattered through commands to the centralized internal/prompter interface (with mocked tests via moq). survey/v2 is still a transitive dependency for legacy UI elements.
• Hub-style CLI: although hub (the unofficial predecessor) is not in this repo, docs/gh-vs-hub.md preserves the rationale for splitting from it.

Major rewrites and migrations

• Config v1 to v2 (internal/config/migration/): introduced when the CLI added multi-account support. The migration code still lives alongside the loader so older config files continue to upgrade in place. See docs/multiple-accounts.md.
• ProjectsV1 to ProjectsV2: each gh project command was rewritten against the GraphQL ProjectsV2 API. Look for // TODO ProjectsV1Cleanup markers under pkg/cmd/project/ for the cleanup tail.
• go-gh extraction: the lower-level HTTP and auth code lives in cli/go-gh. api/client.go is now a thin wrapper that adds GitHub-specific headers, telemetry, and SSO redirect handling on top of go-gh's api.NewGraphQLClient and api.NewRESTClient.
• Telemetry over Twirp (2024 - 2025): the internal/barista/observability/telemetry.twirp.go client (40 KB, generated) replaced ad-hoc HTTP posts. The internal/telemetry/ service now batches events and supports a log mode that flushes a human-readable summary to stderr.
• Skills introduction (2025): not a rewrite but an entirely new top-level subsystem. It accounts for ~78 of 404 pkg/cmd change events in the last 90 days.

Growth trajectory

• 2019-2020: single-digit committers, foundational packages.
• 2021-2022: the GitHub CLI team grows; Codespaces, Actions (gh run, gh workflow), and gh extension arrive.
• 2023-2024: dependency hygiene (golangci-lint ratchets up), license-compliance tooling (internal/licenses), attestation, multi-account support.
• 2025-2026: AI tooling becomes a first-class concern: agent detection, gh skill, gh agent-task, gh accessibility, gh copilot, and a corresponding telemetry service.

The longest-tenured contributors (by commit count on trunk, excluding bots) are Mislav Marohnić, Kynan Ware, William Martin, vilmibm, Nate Smith, Babak K. Shandiz, Andy Feller, Corey Johnson, Meredith Lancaster (the dominant author of pkg/cmd/attestation/), and Sam Coe. Subsystem-specific ownership (e.g. Codespaces, attestation, skills) is enforced via .github/CODEOWNERS and surfaced in maintainers.md.