Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/agent0ai/space-agent/backend-referencenpx skills add agent0ai/space-agent --skill backend-referencegit clone --depth 1 https://github.com/agent0ai/space-agentWhat it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00029 | $0.01470 |
| Opus 5 | $0.00015 | $0.00735 |
| Sonnet 5 | $0.00006 | $0.00294 |
| Haiku 4.5 | $0.00003 | $0.00147 |
Grade A, and why
Backend Reference scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
Copies of this mod
1 near-identical copy found in the catalogue:
- Backend Reference — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 84 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Use this skill when frontend work depends on understanding backend behavior. This skill is read-only context, not authorization to change backend files.
Hard Boundary
- Do not edit
server/,commands/, orpackaging/from this skill set. - If the task truly requires backend changes, stop and ask instead of treating this skill as permission.
- Backend changes are non-standard in this project. Only ask for them when frontend-only work cannot safely enforce security, integrity, cross-user isolation, or runtime stability.
- When you ask, explain why the frontend solution would be insufficient and describe the narrow backend change required.
Page And Request Flow
Current request order is:
- API preflight handling
/api/proxy/api/<endpoint>/mod/.../~/...and/L0/...,/L1/...,/L2/...- page shells and page actions
The browser app mounts through page shells in server/pages/. /login is public. / and /admin require authentication.
API Families
Important frontend-facing endpoint families are:
- app files:
file_list,file_paths,file_read,file_write,file_delete,file_copy,file_move,file_info,folder_download - local history:
git_history_list,git_history_diff,git_history_preview,git_history_rollback,git_history_revert - modules:
module_list,module_info,module_install,module_remove - runtime and identity:
extensions_load,password_generate,password_change,user_crypto_session_key,user_self_info
These endpoints are thin wrappers over shared helpers in server/lib/customware/ and server/lib/auth/.
file_write still defaults to whole-file replacement, but it also supports operation: "append", "prepend", and "insert". Insert writes accept exactly one anchor through line, before, or after, use the first literal before or after match, treat line as a 1-based insertion point, and require utf8.
file_list and file_paths support access: "write" or writableOnly: true for writable-only discovery. They also support gitRepositories: true; with a pattern such as **/.git/, file_paths returns local-history owner roots like L1/team/ and L2/alice/ without exposing reserved .git metadata paths.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2d ago First seen · 84 lines · 29 tokens per session scan A 0137fc83f230
Backend Reference is a skill published in the GitHub repository agent0ai/space-agent (1,390 stars, last pushed 2mo ago), licensed MIT. It adds 29 tokens to every session and 1,470 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
systematic-debugging
Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.
brainstorming
You MUST use this before any creative work - creating features, building components, adding functionality, or modifying behavior. Explores user intent, requirements and design before implementation.
chat-pet-sprite-creation
Use when creating or changing VS Code chat pet sprite art, sprite sheets, state animations, eye treatments, Stable/Insiders variants, or pet transitions under src/vs/workbench/contrib/chat/browser/widget/media/chatPet.
cpu-profile-analysis
Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…
agent-host-chat-contributions
Build and review cross-cutting agent-host chat behavior through lifecycle contributions. Use when adding turn lifecycle side effects, prompt or context injection, restored-history transformation, protocol-action observation, or when reviewing changes that add code to AgentSideEffects or AgentService.
auto-perf-optimize
Run agent-driven VS Code performance or memory investigations. Use when asked to launch Code OSS, automate a VS Code scenario, run the Chat memory smoke runner, capture renderer heap snapshots, take workflow screenshots, compare run summaries, or drive a repeatable scenario before heap-snapshot analysis.