spec

A short software specification that records the request, expected behavior, files to change, and commands that prove the work is complete.

In plain words
What is it for?
Use it to plan a coding task, describe behavior for empty, boundary, and error inputs, identify affected files, and define end-to-end checks.
Why use it?
It gives implementation a clear target and helps prevent the work from drifting beyond the original request. It also makes edge cases and unfinished dependencies explicit before coding starts.

Command

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 commands/ashkaan/contextium/spec
Clone the repo
git clone --depth 1 https://github.com/Ashkaan/contextium
Per session 16 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 266 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 $0.00016 $0.00266
Opus 5 $0.00008 $0.00133
Sonnet 5 $0.00003 $0.00053
Haiku 4.5 $0.00002 $0.00027

Measured yesterday against content hash aef0d2deed8a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

spec 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 yesterday.

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.

templates/commands/spec.md · 15 lines

What it actually says

Write the SPEC. Four sections, no more:

  1. Ask — what was asked for, in the asker's own words. This is what the finished work gets checked against, and it is what keeps the build from drifting into something fancier than was wanted.
  2. Behavior — what success looks like, concretely: given these inputs, the system does this. Include the edges: 0, 1, empty, max, and error.
  3. Files — what to create or change, one line each, naming the existing pattern each one mirrors. List the downstream callers you'll update in the same pass; nothing deferred.
  4. Done — the exact commands to run and the output that means success. Not "tests pass" — the command and the expected result, including at least one end-to-end check.

Then review it before building — /spec-audit. Resolve anything the design left vague now: a SPEC that says "whatever config that other thing uses" is a guess wearing a spec's clothes.

Stop after the SPEC. The build happens in a fresh chat, so the context that grew attached to the plan is not the one that judges the result.

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. yesterday First seen · 15 lines · 16 tokens per session scan A aef0d2deed8a

Subscribe to this mod's changes

spec is a command published in the GitHub repository Ashkaan/contextium (32 stars, last pushed 4d ago), licensed MIT. It adds 16 tokens to every session and 266 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.