implement-plan

A command for carrying out an approved technical plan stored in the thoughts/tasks/ directory. The plan is a written sequence of work phases with specific changes and success checks.

In plain words
What is it for?
Use it when you already have an approved plan and want its phases implemented, checked, and updated as each part is completed.
Why use it?
It gives implementation a clear sequence and keeps progress visible through task checkboxes. It also requires the surrounding ticket and referenced files to be read before changes begin.

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/ihorkatkov/pantheon/implement-plan
Clone the repo
git clone --depth 1 https://github.com/ihorkatkov/pantheon
Per session 22 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 737 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 $0.00022 $0.00737
Opus 5 $0.00011 $0.00368
Sonnet 5 $0.00004 $0.00147
Haiku 4.5 $0.00002 $0.00074

Measured 2d ago against content hash 24e31933e03c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

implement-plan 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.

.opencode/commands/implement-plan.md · 91 lines

How it starts

The opening of the file, as written. The whole thing — 91 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Implement Plan

You are tasked with implementing an approved technical plan from thoughts/tasks/ directory. These plans contain phases with specific changes and success criteria.

Getting Started

When given a plan path:

  • Read the plan completely and check for any existing checkmarks (- [x])
  • Read the original ticket and all files mentioned in the plan
  • Read files fully - never use limit/offset parameters, you need complete context
  • Think deeply about how the pieces fit together
  • Create a todo list to track your progress
  • Start implementing if you understand what needs to be done

If no plan path provided, ask for one.

Implementation Philosophy

Plans are carefully designed, but reality can be messy. Your job is to:

  • Follow the plan's intent while adapting to what you find
  • Implement each phase fully before moving to the next
  • Verify your work makes sense in the broader codebase context
  • Update checkboxes in the plan as you complete sections

When things don't match the plan exactly, think about why and communicate clearly. The plan is your guide, but your judgment matters too.

If you encounter a mismatch:

  • STOP and think deeply about why the plan can't be followed
  • Present the issue clearly:
    Issue in Phase [N]:
    Expected: [what the plan says]
    Found: [actual situation]
    Why this matters: [explanation]
    
    How should I proceed?
    

Verification Approach (TDD Enforced)

After implementing a phase, you MUST follow the TDD cycle and validation:

  1. RED Phase: Verify tests fail before implementation

    • Run project tests (see AGENTS.md) or run a specific test file
    • Confirm tests fail for the right reasons
    • Document that RED phase is complete
  2. GREEN Phase: Implement to make tests pass

    • Write minimal implementation
    • Run project tests (see AGENTS.md)
    • Confirm all tests pass
  3. VALIDATE Phase: Run full validation

    • Run project validation commands (see AGENTS.md)
    • This typically runs: lint, fmt, check, and tests
    • Fix any issues that arise
    • Confirm validation exits with success

Read the full file on GitHub · 91 lines

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. 2d ago First seen · 91 lines · 22 tokens per session scan A 24e31933e03c

Subscribe to this mod's changes

implement-plan is a command published in the GitHub repository ihorkatkov/pantheon (5 stars, last pushed 5mo ago), licensed MIT. It adds 22 tokens to every session and 737 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 2026-08-31.