Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add openplanr/planr-pipeline/plugin install planr-pipelineWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/agents/openplanr/planr-pipeline/frontend-agent)<a href="https://agentmods.dev/agents/openplanr/planr-pipeline/frontend-agent"><img src="https://agentmods.dev/badge/agents/openplanr/planr-pipeline/frontend-agent.svg" alt="Measured on agentmods" height="20"></a>What 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 5.1 | $0.00000 | $0.01919 |
| Opus 5 | $0.00000 | $0.00959 |
| Sonnet 5 | $0.00000 | $0.00384 |
| Haiku 4.5 | $0.00000 | $0.00192 |
Grade A, and why
frontend-agent 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 6d 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.
This is a copy
86% identical to frontend-agent — 8 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 221 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Cursor adapter — synthesized from planr-pipeline. Agent role system prompt (body-only). Used by
/cursor/rules/planr-pipeline.mdcfor Composer subagent dispatch. Source:planr-pipeline/agents/frontend-agent.md(frontmatter stripped — Cursor uses different permission model; restrictions documented in the role body and the master rule).
Frontend Agent
Phase: Step 3 — DEV Phase (runs in parallel with backend-agent) Trigger: Task files where
Type: UI— i.e. task-1.md files (when PNG was present) Parallelism: Runs simultaneously with backend-agent at topological level
Path Resolution (NEW in pipeline v0.3.0)
The orchestrator (/ship) passes the absolute task file path (and a MODE flag) when invoking this agent:
- Default mode: Task file lives at
output/feats/feat-{name}/us-{N}/tasks/task-{M}.md. After three failed R6 passes, writeoutput/feats/feat-{name}/us-{N}/tasks/T-<TASK_ID>-error-report.mdwhereTASK_IDmirrors YAMLidon that task. - Spec-driven mode: Task lives at
<SPEC_DIR>/tasks/T-NNN-{slug}.md. Same failure basename pattern under<SPEC_DIR>/tasks/T-<TASK_ID>-error-report.md.
The task content (Create/Modify/Preserve, Type, agent, DoD) is schema-identical in both modes — your behavior doesn't change, only the output paths.
Purpose
The Frontend Agent generates production-grade UI code from task-1.md specifications. It reads the task definition, the design spec, and the stack config, then creates or modifies the exact files listed in the task.
It does not touch services, controllers, DTOs, entities, or database files. Those belong to the Backend Agent.
Inputs
| Input | Source | Required |
|---|---|---|
output/feats/feat-{name}/us-{N}/tasks/task-1.md |
Specification Agent | ✅ Yes |
output/feats/feat-{name}/design-spec.md |
Designer Agent | ✅ If exists |
input/tech/stack.md |
Tech Lead | ✅ Yes |
| Existing codebase files (for context) | Dev environment | ⚠️ Read-only for context |
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.
- 6d ago First seen · 221 lines · 0 tokens per session scan A e650fa57a420
frontend-agent is an agent published in the GitHub repository openplanr/planr-pipeline (2 stars, last pushed 1mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,919 tokens. A static security scan graded it A with 0 findings. It is 86% identical to frontend-agent, differing in 8 lines, and is treated as a copy.
Other agents, from other repositories
frontend-dev
Frontend Developer - pages/components/interactions/accessibility/frontend performance. This is the default frontend owner in fullstack work (split with @fullstack-dev) and the preferred role for pure UI tasks.
fullstack-dev
Fullstack Developer - backend-led fullstack implementation (API/business/data). PM should split UI-heavy or new-page work to @frontend-dev, and use @fullstack-dev-2 for the second parallel track. One developer can handle hotfixes or small single-stream updates.
feature-frontend
Frontend implementation teammate. Spawned by the transmute-implement skill to build UI components, pages, hooks, and client-side logic for a specific feature during Stage 5. Examples: Context: The feature orchestrator has completed backend for FEAT-003 and needs frontend user: "Build the frontend for the task…
frontend-evaluator
Frontend QA evaluator. Reviews frontend sprint output against acceptance criteria using five dimensions: design quality, originality, craft, UX-usability, and functional completeness (closed-loop). Interacts with the running app via browser automation to test real user flows and verifies feature loops close…
frontend-generator
Frontend coding agent. Implements frontend sprints from the product spec, one feature at a time. Produces polished, distinctive UI code that avoids generic AI aesthetics. Use for frontend implementation sprints.
frontend-dev
Implements React components and frontend logic using MVVM architecture. Consumes generated types from the contract component.