You have a plan in ChatGPT that finally looks right. The next step belongs in Claude because that is where you want to implement it. Opening Claude and typing “build this” leaves out the exact constraints that made the plan acceptable. Pasting the entire planning chat gives Claude every abandoned path as well as the one you chose.
The useful boundary is a plan-to-build checkpoint: a short record of what is settled, what is uncertain, and what Claude should change first.
Stop when the plan becomes executable
Do not hand off at an arbitrary point in the conversation. Stop when you can answer four questions:
- What outcome should the implementation produce?
- Which approach did you accept?
- Which constraints must the implementation preserve?
- What is the first concrete change or test?
If one answer is still missing, keep planning or mark it as an open question. A vague gap should not become a confident instruction merely because it crossed into another assistant.
Separate what you confirmed from what ChatGPT inferred. “The endpoint must remain backward compatible” may be your requirement. “The existing client probably retries” may only be a model inference. Labeling those differently lets Claude challenge the second without reopening the first. Separating facts from a guess gives the underlying rule.
Write the implementation brief
The brief should let a coding assistant begin without reconstructing the planning session. Include:
- Outcome: the behavior a person or calling system should observe.
- Accepted approach: the design you chose, in a few direct sentences.
- Constraints and non-goals: compatibility, security, performance, scope, and anything deliberately excluded.
- Rejected options: only the plausible paths Claude might otherwise reopen, with the reason each is closed.
- Repository coordinates: repository name, branch, exact commit or tag, relevant file paths, and the part of the code they contain.
- Evidence: the command already run, its exact result, or the failure that motivated the work.
- Next ask: the first implementation step and the checks that should pass.
Paths are often better than pasted source. They tell Claude where to look while leaving the repository as the source of truth.
Send a self-handoff, not a context dump
If ChatGPT and Claude connect to the same RelayLink account, use the ordinary draft, review, and explicit-confirm flow addressed to your own email. A self-handoff needs no second account or contact request, creates no email or magic link, and remains unread until any assistant pulls it. The account portal is the fallback inbox.
That is not automatic context synchronization. RelayLink carries only the structured text you approved, not hidden memory, chat history, browser state, or a project. A self-addressed briefing is a checkpoint between sessions, not a shared mind.
Give Claude the working environment separately
Claude needs its own authorized access to the repository and the named branch or commit. RelayLink packages carry text only. They do not attach files, clone repositories, preserve a terminal, or reproduce the state of a coding tool.
Do not put API keys, webhook secrets, customer data, or confidential source into the handoff unless both the recipient and the AI provider are authorized to receive it. Prefer a file path, commit identifier, issue reference, or safe excerpt. Check your employer’s and providers’ data rules before moving protected work between services.
Test the result against the checkpoint
Claude’s implementation is not correct because it follows ChatGPT’s plan, and ChatGPT’s plan is not correct because Claude can implement it. Run the named tests, inspect the diff, and compare the observed behavior with the outcome you approved.
If implementation reveals a false assumption, update the checkpoint rather than defending it. The goal of splitting the work is a cleaner boundary between planning and building. The human still owns both the plan and the verdict.