Proof-of-value playbook for API evaluation

You are not buying an API because you need another tool. You are buying confidence that closeout deadlines will not slip silently.

Use this 5-step path during prospect exploration:

Step 1: Verify the states you care about

Start with /api/v1/supported-states.

Your outcome: a short list of jurisdictions your pilot can safely cover today.

Step 2: Test one invoice per core state

Run /api/v1/calculate-deadline for a real invoice pattern per state (e.g., CA, TX, FL).

Your outcome: proof that the endpoint returns dates your team can trust.

Step 3: Compare legal context

Open /api/v1/state-guides/{state} for each core state you test.

Your outcome: stakeholder confidence in state-by-state differences.

Step 4: Build the first exception plan

Design what happens when deadlines are missed or when states are unsupported.

Your outcome: a real operational playbook, not just an API green checkmark.

Step 5: Decide pilot scope

Document:

• which states passed
• which states still need legal review
• a 30-day pilot timeline and success metrics

This sequence is simple on purpose because you should be deciding quickly whether to proceed, not inventing heavy middleware before you know if the endpoint solves your core risk.

Output you can bring to a planning meeting

1. A screenshot or export of the state list
2. 3–6 realistic test calculations
3. A one-page exception policy for failed states and late deadlines

When this is complete, you can move from curiosity to procurement review in the same week.