GECK

The Sprint Zero launcher for Animus Sprint Loops.

GECK generates the two artifacts that start a Sprint Loop with full context:

• mission-spec.md — a durable, tracked, root-level mission document
  (goal, success criteria, constraints, working agreement, backlog seeds).
  This is the drift baseline every sprint compares against as building
  happens.
• launch-prompt.md — the complete instructional prompt you paste into
  Claude Code, Codex CLI, or an open harness to start Sprint 0 correctly,
  wired into Sprint Loops' own persistence machinery.

It also seeds the target project's Sprint Loops state — decisions.md
(an ADR pointing at the spec), agent-tasks/agent-tasks.md (backlog seeds),
and confidence.txt — deterministically and idempotently, so the mission
context flows into every subsequent sprint automatically.

Why this exists

Animus Sprint Loops already solves cross-session persistence well: typed
backlog tasks, per-task git commits, an ADR log, an enforced research budget.
The one thing it doesn't durably keep is the mission — a sprint's goal
today enters as ephemeral prompt text and survives only as a one-line summary
in a gitignored sprints/ directory. Launching Sprint 0 "properly" meant
hand-writing a rich prompt from scratch every time, with the full intent
evaporating once the session ended.

GECK closes that gap. mission-spec.md is the one thing worth keeping from
GECK's earlier incarnation as a standalone memory protocol (see
v1.3-protocol-final for that history) —
repurposed as the upstream launcher for a protocol that already does
everything else better.

Because Sprint Loops' finalize-plan.sh already forces every Research Phase
to review decisions.md, the ADR GECK seeds (ADR-000) makes every future
sprint re-read the mission spec and report drift automatically — no changes
to Sprint Loops required.

Install

git clone https://github.com/crussella0129/Animus_GECK.git
cd Animus_GECK
cargo build --release --bin geck
# target/release/geck (or target/<triple>/release/geck)

Requires Rust 1.75+. geck is a single native binary with no other runtime
dependency — it does not itself need Git Bash or WSL (Sprint Loops' shell
scripts do; see the harness-specific notes in the generated prompt).

Quick start

# Interactive wizard — no flags launches it
geck launch

# Or fully non-interactive
geck launch \
  --path ./my-project \
  --project-name "My Project" \
  --goal "Ship a REST API with auth, rate limiting, and OpenAPI docs." \
  --profile api \
  --criterion "All endpoints have integration tests" \
  --non-goal "Not building a frontend" \
  --harness claude-code \
  --merge-mode approve \
  --work-branch dev \
  --charter "Survey the existing auth middleware before designing the new API." \
  --backlog-seed "Add rate limiting middleware"

This writes my-project/mission-spec.md and my-project/launch-prompt.md,
and seeds my-project/decisions.md, my-project/agent-tasks/agent-tasks.md,
and my-project/confidence.txt. Paste the contents of launch-prompt.md
into your agent session to start Sprint 0. See docs/example/
for a worked pair of artifacts.

Re-rendering the prompt

If you hand-edit mission-spec.md, or the installed Sprint Loops skill has
moved on since you launched, regenerate just the prompt:

geck prompt --path ./my-project
geck prompt --path ./my-project --harness codex-cli   # switch target harness

mission-spec.md's YAML frontmatter is the source of truth geck prompt
re-parses — it never re-derives the prompt from anything else.

Commands

Run geck launch --help for the full non-interactive flag list.

The wizard

geck launch with no arguments opens a menu-driven wizard: every section —
project name, path, repo URL (auto-detected from git when the path is a
repo root), profile, goal, success criteria, non-goals, languages,
must-use/must-avoid, platforms, harness, merge mode, work branch, Sprint 0
charter, backlog seeds, extra stop-checkpoints, and a seed toggle — is
visible on the menu at all times. Edit any section in any order, preview
both generated artifacts, then save.

mission-spec.md

---
geck: '2.0'
project: My Project
created: 2026-07-21
profile: api
harness: claude-code
merge_mode: approve
work_branch: dev
repo: https://github.com/you/my-project.git
sprint_loops_ref: 2026-07-21
---
# Mission: My Project

## Goal
...

## Success Criteria
Mission-level definition of done. Checked off across sprints, not per-sprint.
- [ ] ...

## Non-Goals
...

## Constraints
...

## Working Agreement
- **Merge mode:** approve — a human approves each sprint's PR before it merges.
- **Work branch:** dev

## Sprint 0 Charter
...

## Backlog Seeds
- T-101 (backlog): ...

## Amendment Protocol
This file is amended by humans only. ...

The frontmatter is machine-readable (what geck prompt re-parses); the body
is the human-readable mission document. This file is amended by humans
only — an agent proposing a change records an ADR in decisions.md
referencing the relevant section instead of editing the spec directly.

Relationship to Animus Sprint Loops

GECK is a launcher, not an adapter. Animus Sprint Loops
remains the canonical protocol — its open-harnesses/, claude-code/, and
codex-cli/ bundles are unmodified by this project. GECK only writes into a
Sprint-Loops-shaped project before Sprint 0 starts: the seeds it writes
(decisions.md, agent-tasks/, confidence.txt) use the exact schemas
Sprint Loops itself defines, and init-sprint.sh's own [ -f ] guards mean
it never clobbers what GECK seeded.

Profiles

21 built-in profiles (website, web_app, api, cli_tool, data_science, devops,
game, embedded, blockchain, and more) seed a spec's languages, frameworks,
platforms, and suggested success/must-use/must-avoid criteria. List them
with geck list-profiles; profile values only fill fields you haven't set
explicitly.

Development

cargo build --workspace
cargo test --workspace
cargo fmt --all
cargo clippy --workspace --all-targets

Two crates: geck-core (the library — spec model, templates, scaffolding,
profiles) and geck-cli (the geck binary — CLI + wizard).

License

See LICENSE file.