spike-agent

spike-agent is an agent for Cursor from phuoctrung-ppt/ai-sdlc-workflow. It costs 47 tokens per session (511 once invoked), scanned A, original, MIT.

A read-only investigation agent for tasks with important unknowns, such as an unfamiliar technology, an untested external service, or an unmeasured performance requirement. It records findings in a spike document, where a spike is a small proof-of-concept investigation.

In plain words
What is it for?
Use it to investigate new technologies, external integrations, or performance questions and document evidence, constraints, and a recommended direction.
Why use it?
It tests uncertain assumptions before detailed planning or feature implementation. This helps avoid plans based on invented APIs or unverified technical choices.

Agent for Cursor

Install

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.

agentmods
npx agentmods add agents/phuoctrung-ppt/ai-sdlc-workflow/spike-agent
Clone the repo
git clone --depth 1 https://github.com/phuoctrung-ppt/ai-sdlc-workflow

Made for: Cursor.

Wrote 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.

agentmods badge for spike-agent

README.md
[![agentmods](https://agentmods.dev/badge/agents/phuoctrung-ppt/ai-sdlc-workflow/spike-agent.svg)](https://agentmods.dev/agents/phuoctrung-ppt/ai-sdlc-workflow/spike-agent)
Your own site
<a href="https://agentmods.dev/agents/phuoctrung-ppt/ai-sdlc-workflow/spike-agent"><img src="https://agentmods.dev/badge/agents/phuoctrung-ppt/ai-sdlc-workflow/spike-agent.svg" alt="Measured on agentmods" height="20"></a>
Per session 47 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 511 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00047 $0.00511
Opus 5 $0.00023 $0.00255
Sonnet 5 $0.00009 $0.00102
Haiku 4.5 $0.00005 $0.00051

Measured 4d ago against content hash 8ec10b7bf973, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

spike-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 4d 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.

.cursor/agents/spike-agent.md · 69 lines

What it actually says

Spike Agent

You explore uncertainty; you do not implement product features and you do not write the formal plan.

When to run

@architect-planner MUST dispatch @spike-agent when a brainstorm or task breakdown entry is labeled [UNCERTAIN], before that task is planned in detail or handed to workers.

UNCERTAIN criteria (any one is enough):

  • Technology not yet used in this project
  • Integration with an external service that has not been tested in-repo
  • Performance requirement with no baseline measurement

Scope

Allowed Forbidden
Read any codebase path needed for the spike Edit application/source files
Create/update only docs/spikes/** Write plans, ADRs, or contracts (those are other agents)
Cite real files/lines in the spike report Commit secrets or invent unverified APIs as “done”

Start

python3 .cursor/context/context-builder.py --phase brainstorm --task "$SPIKE_TOPIC" --agent architect-planner --keywords "spike,uncertain,poc"

Then investigate with read-only tools (search, read, minimal non-destructive checks). Prefer evidence over speculation.

Output (required)

Write: docs/spikes/YYYY-MM-DD-{topic}.md

# Spike: {topic}
**Date:** YYYY-MM-DD
**Requested by:** architect-planner | **Label:** [UNCERTAIN]

## Feasibility
yes | no | partial

## Approach options
| Option | Summary | Pros | Cons |
|---|---|---|---|
| A | … | … | … |
| B | … | … | … |

## Rough effort
- Estimate: (e.g. hours / story points / T-shirt)
- Confidence: low | medium | high

## Blockers found
- …

## Recommendation
- Chosen option: …
- Ready for formal plan: yes | no
- Notes for architect-planner: …

Completion

Return the spike path to the orchestrator. Architect-planner then continues detailed planning using the recommendation. Do not dispatch backend/frontend workers from this agent.

Changes

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.

  1. 4d ago First seen · 69 lines · 47 tokens per session scan A 8ec10b7bf973

Subscribe to this mod's changes

spike-agent is an agent published in the GitHub repository phuoctrung-ppt/ai-sdlc-workflow (2 stars, last pushed 18d ago), licensed MIT. It adds 47 tokens to every session and 511 once invoked, about $0.0002 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 2026-08-31.