Client API Handoff Pack (Handoff)

Client API Handoff Pack (Handoff)

1. 01

   Freeze the spec and tag the release before writing any handoff document

   Export the OpenAPI file from the design workspace (Apidog or equivalent) and stamp it with a version number and date. A handoff pack that references a moving spec is worthless within a week.

2. 02

   Assemble the credential and access register with named owners

   List every key, token, webhook secret, and gateway policy that touches the client's stack, plus who holds admin rights on each. Forrester's November 2026 research flags vendors that control metering, access, and dispute resolution simultaneously, so the client needs to see exactly where their dependency sits.

3. 03

   Publish the developer-facing reference from the frozen spec, not from memory

   Generate the interactive reference and auth examples from the spec file so the client's in-house team can test endpoints without calling your delivery lead. ReadMe-style portals do this automatically; a static PDF does not.

4. 04

   Document the failure modes the client will actually hit

   Cover rate limits, retry and backoff behaviour, token spend caps on any LLM route, and what happens when an upstream provider changes pricing or deprecates a model. Gemini 4 Carbon's December 1 price change is the kind of event a handoff doc should already anticipate.

5. 05

   Run a live walkthrough with the client's receiving engineer on a sandbox key

   Have them authenticate, call two endpoints, and trigger one deliberate error. Handoffs fail when the receiving team reads the docs but never executes against them.

6. 06

   Set the post-handoff support window in writing

   State the number of days of included break-fix support, the response time, and the hourly rate beyond that window. This is the line between a clean handoff and an unpaid retainer.

7. 07

   Archive the pack in the client's own repository, not only yours

   A handoff that lives exclusively in agency storage creates lock-in the client will eventually resent. Mirror the spec, docs, and access register into their version control.