# Contributing to The Nexus

## Issue Assignment — The Lock Protocol

**Rule: Assign before you code.**

Before starting work on any issue, you **must** assign it to yourself. If an issue is already assigned to someone else, **do not submit a competing PR**.

### For Humans

1. Check the issue is unassigned
2. Assign yourself via the Gitea UI (right sidebar → Assignees)
3. Start coding

### For Agents (Claude, Perplexity, Mimo, etc.)

1. Before generating code, call the Gitea API to check assignment:
   ```
   GET /api/v1/repos/{owner}/{repo}/issues/{number}
   → Check assignees array
   ```
2. If unassigned, self-assign:
   ```
   POST /api/v1/repos/{owner}/{repo}/issues/{number}/assignees
   {"assignees": ["your-username"]}
   ```
3. If already assigned, **stop**. Post a comment offering to help instead.

### Why This Matters

On April 11, 2026, we found 12 stale PRs caused by Rockachopa and the `[claude]` auto-bot racing on the same issues. The auto-bot merged first, orphaning the manual PRs. Assignment-as-lock prevents this race condition.

---

## Branch Protection & Review Policy

All repositories enforce these rules on `main`:

| Rule | Status |
|------|--------|
| Require Pull Request for merge | ✅ Enabled |
| Require 1 approval before merge | ✅ Enabled |
| Dismiss stale approvals on new commits | ✅ Enabled |
| Require CI to pass (where CI exists) | ⚠️ Conditional |
| Block force pushes to `main` | ✅ Enabled |
| Block deletion of `main` branch | ✅ Enabled |

### Default Reviewer Assignments

| Repository | Required Reviewers |
|------------|-------------------|
| `hermes-agent` | `@perplexity`, `@Timmy` |
| `the-nexus` | `@perplexity` |
| `timmy-home` | `@perplexity` |
| `timmy-config` | `@perplexity` |

### CI Enforcement Status

| Repository | CI Status |
|------------|-----------|
| `hermes-agent` | ✅ Active |
| `the-nexus` | ⚠️ CI runner pending (#915) |
| `timmy-home` | ❌ No CI |
| `timmy-config` | ❌ Limited CI |

---

## Branch Naming

Use descriptive prefixes:

| Prefix | Use |
|--------|-----|
| `feat/` | New features |
| `fix/` | Bug fixes |
| `epic/` | Multi-issue epic branches |
| `docs/` | Documentation only |

Example: `feat/mnemosyne-memory-decay`

---

## PR Requirements

1. **Rebase before merge** — PRs must be up-to-date with `main`. If you have merge conflicts, rebase locally and force-push.
2. **Reference the issue** — Use `Closes #NNN` in the PR body so Gitea auto-closes the issue on merge.
3. **No bytecode** — Never commit `__pycache__/` or `.pyc` files. The `.gitignore` handles this, but double-check.
4. **One feature per PR** — Avoid omnibus PRs that bundle multiple unrelated features. They're harder to review and more likely to conflict.

---

## Path Conventions

| Module | Canon Path |
|--------|-----------|
| Mnemosyne (backend) | `nexus/mnemosyne/` |
| Mnemosyne (frontend) | `nexus/components/` |
| MemPalace | `nexus/mempalace/` |
| Scripts/tools | `bin/` |
| Git hooks/automation | `.githooks/` |
| Tests | `nexus/mnemosyne/tests/` |

**Never** create a duplicate module at the repo root (e.g., `mnemosyne/` when `nexus/mnemosyne/` already exists). Check `FEATURES.yaml` manifests for the canonical path.

---

## Feature Manifests

Each major module maintains a `FEATURES.yaml` manifest that declares:
- What exists (status: `shipped`)
- What's in progress (status: `in-progress`, with assignee)
- What's planned (status: `planned`)

**Check the manifest before creating new PRs.** If your feature is already shipped, you're duplicating work. If it's in-progress by someone else, coordinate.

Current manifests:
- [`nexus/mnemosyne/FEATURES.yaml`](nexus/mnemosyne/FEATURES.yaml)

---

## Workflow

1. Check the issue is unassigned → self-assign
2. Check `FEATURES.yaml` for the relevant module
3. Create feature branch from `main`
4. Submit PR with clear description and `Closes #NNN`
5. Wait for reviewer approval
6. Rebase if needed, then merge

### Emergency Exceptions

Hotfixes require:
- ✅ @Timmy approval
- ✅ Post-merge documentation
- ✅ Follow-up PR for full review

---

## Large-Repo Clone Strategy

Some repos in this org (hermes-agent, the-nexus as it grows) can exceed 1000 tracked files, which causes `git clone --depth 1` to time out and also hits the Gitea tree-API cap of 1000 entries.

### Recommended clone patterns for agents

**Blobless partial clone** — fastest overall; metadata arrives immediately, blobs are fetched on demand:
```sh
git clone --filter=blob:none --depth 1 <repo-url>
```

**Treeless partial clone** — skips tree objects for past commits; best when you need full working tree but not history:
```sh
git clone --filter=tree:0 <repo-url>
```

**Sparse checkout** — only materialise the subdirectories you actually need:
```sh
git clone --filter=blob:none --no-checkout <repo-url> myrepo
cd myrepo
git sparse-checkout init --cone
git sparse-checkout set nexus tests          # only check out these dirs
git checkout main
```

### Gitea tree API workaround

When the tree endpoint returns exactly 1000 entries and you suspect truncation, pass `recursive=1` and page through with the `page` parameter:
```
GET /api/v1/repos/{owner}/{repo}/git/trees/{sha}?recursive=1&page=2
```

### Why `.gitattributes` export-ignore exists

Directories marked `export-ignore` in `.gitattributes` are excluded from `git archive` tarballs and future sparse-export tooling. This reduces the surface area for export-based agent workflows. It does **not** affect `git clone` directly — use the partial-clone flags above for that.

---

## Stale PR Policy

A cron job runs every 6 hours and auto-closes PRs that are:
1. **Conflicted** (not mergeable)
2. **Superseded** by a merged PR that closes the same issue or implements the same feature

Closed PRs receive a comment explaining which PR superseded them. If your PR was auto-closed but contains unique work, reopen it, rebase against `main`, and update the feature manifest.

---

## CI/CD Requirements

All main branch merges require (where applicable):
- ✅ Linting
- ✅ Unit tests
- ⚠️ Integration tests (pending for the-nexus, see #915)
- ✅ Security scans