---
title: "B2B Identity Resolution API: Developer Guide (2026)"
description: "Evaluate B2B identity resolution APIs by input, output, authentication, data quality and delivery. Includes current Leadpipe docs and a rollout checklist."
canonical_url: "https://www.leadpipe.com/blog/b2b-identity-resolution-api-guide/"
source_url: "https://www.leadpipe.com/blog/b2b-identity-resolution-api-guide/"
md_url: "https://www.leadpipe.com/blog/b2b-identity-resolution-api-guide.md"
content_type: "article"
pubDate: "2026-03-10T00:00:00.000Z"
last_updated: "2026-09-23T00:00:00.000Z"
---

# B2B Identity Resolution API: Developer Guide (2026)

Quick answer

Choose an identity resolution API by the signal you can provide and the entity you need back. Visitor retrieval, known-contact enrichment and customer-record unification are different interfaces. Verify authentication, field availability, organization boundaries and delivery behavior before integrating.

An API that enriches an email address does not automatically identify an anonymous website visitor. An API that returns an identified visitor does not necessarily accept arbitrary emails for lookup. Start with the input and output before comparing vendors or copying code.

At Leadpipe, we support visitor identification and delivery into a team’s existing workflow. This guide explains how to evaluate that integration and uses the current public documentation for Leadpipe-specific details. It is not a performance benchmark or a claim that every identity product shares the same architecture.

For company-level input, Leadpipe also offers an [IP to Company API](/product/ip-to-company/): look up stored company information from IPv4 or IPv6 without treating the result as a named visitor. Use the [firmographic data guide](/blog/firmographic-data/) to define the account fields your workflow needs.

## Choose the right identity interface

| Interface | Starting point | Useful output | What to verify |
| --- | --- | --- | --- |
| Visitor identification and retrieval | Supported activity on an installed website | Available resolved visitor records and context | Pixel scope, identity level, regions and account access |
| Contact enrichment | An existing supported identifier | Additional fields about a record | Accepted inputs, ambiguity, field provenance and usage terms |
| Customer identity resolution | Records from your own customer systems | Links or unified profiles | Merge rules, conflict handling and reversal |
| Intent audience access | A defined topic or audience query | Eligible audience results | Topic definition, freshness, entitlement and permitted use |

Both B2B and consumer systems can use exact identifiers and inference. Neither market has one universal matching method. A provider’s “deterministic” label does not establish that every source record is correct. Use the [identity graph guide](/blog/glossary-identity-graph/) for the underlying concepts and the [API comparison](/blog/identity-resolution-api-comparison-2026/) for category-specific vendor evaluation.

## Leadpipe: start with account status and visitor retrieval

The [official quickstart](https://docs.leadpipe.com/api-reference/quickstart) documents an organization API key sent in the `X-API-Key` header. Keep that key on your backend or in a secret manager. The browser pixel uses its own supplied snippet; it must not contain your organization API key.

The documented starting sequence is:

1. Check account status and the available credits, pixels and access.
2. Request visitor records for the intended date range and site scope.
3. Inspect the returned `data` and pagination `meta`.
4. Validate records before writing to a downstream system.

Use the exact requests from the linked quickstart. It documents `pixelId` or `domain` to scope a visitor read; do not combine them. An empty result can reflect no identified activity in the selected scope. Diagnose that separately from an authentication failure.

### Separate collection, retrieval and delivery

The pixel collects supported website activity. A backend read retrieves available records. A webhook delivers qualifying events to your receiver. Treat these as separate operations with separate success checks.

| Layer | Check before continuing | Evidence to keep |
| --- | --- | --- |
| Collection | Correct pixel installed on the intended domain | Verified pixel and scope |
| Retrieval | Correct organization, date range and site filter | Redacted response and pagination metadata |
| Acceptance | Required identity, fit and field checks passed | Accepted, rejected and unresolved counts |
| Delivery | Destination record belongs to the right owner | Redacted delivery result and destination identifier |

A successful HTTP response from a visitor-list endpoint does not prove that your receiver processes webhooks. A synthetic webhook test does not prove a real visitor meets the selected segment.

## Design the destination before adding volume

Write a short contract for your receiving workflow. This is an implementation checklist, not a Leadpipe response schema.

- **Identity unit:** company, matched person or suggested contact.
- **Required fields:** the minimum fields that make the next action possible.
- **Source and time:** retain what was observed, when, and which system supplied it.
- **Ownership:** preserve an existing account or contact owner.
- **Duplicate behavior:** define when to update, skip or request a human review.
- **Suppression:** apply the appropriate exclusions before downstream action.
- **Correction:** define how a disputed record is corrected or removed.

Do not key a person solely by company name or full name. Do not overwrite a verified CRM field simply because an API response arrived later. Resolve conflicts according to an explicit source policy.

For an integration where some fields are missing, allow a record to remain unresolved. A blank field and a negative result are different states. Do not replace an unknown job title with a guess to make a schema appear complete.

## Choose polling or webhooks deliberately

Polling can fit a controlled batch workflow. Track the documented page or cursor state and the scope of each successful read. Do not treat page one as the entire dataset.

Webhooks can fit event-driven delivery. Leadpipe’s [webhook guide](https://docs.leadpipe.com/guides/set-up-webhooks) distinguishes **First Match** from **Every Update** and describes delivery history and auto-disabled status. Choose the trigger that your receiving system can process.

Before unattended use, verify the receiver with a redacted test payload and inspect a live qualifying delivery. Confirm authentication or signing, timeout, retry schedule and replay controls with the provider. The guide does not establish universal guarantees for those behaviors, and an Identification API response is not a substitute for a webhook fixture.

### Receiver acceptance checklist

| Case | Expected behavior you should define |
| --- | --- |
| Same payload arrives twice | No unintended duplicate destination record |
| Optional field is absent | Record remains valid if the field is not required |
| Required field is absent | Hold for review or reject with a reason |
| Destination is unavailable | Bounded recovery with visible failure state |
| Existing customer or active deal | Preserve ownership and suppression policy |
| Record is disputed | Traceable correction or removal path |

These are recommended checks for your integration. They are not claims that every vendor implements them automatically.

## Handle errors by endpoint

Use the [authentication and errors reference](https://docs.leadpipe.com/api-reference/authentication-and-errors) for the actual operation. It distinguishes invalid requests, authentication failures, missing access, resource conflicts and rate limits. Identification and Orbit do not share one universal error envelope.

For visitor reads, use the returned rate-limit headers and `Retry-After` where documented. Avoid hardcoding an allowance from a different API. Read-only HTTP semantics also do not establish that an operation is free: the documentation identifies company lookups that consume an allowance.

Capture the method, path, status and request identifier when available. Redact credentials and personal records from shared logs. Before retrying a write, establish whether it supports safe repetition; an idempotency option on one endpoint is not a platform-wide guarantee.

## Evaluate quality at the field and workflow level

Begin with a representative cohort and record the included pages, regions and observation window. Keep company and person output separate. Inspect the identity association independently of whether an email is deliverable or a job title looks plausible.

The [data-quality guide](https://docs.leadpipe.com/guides/understanding-data-quality) is a starting reference for interpreting Leadpipe records. Your own acceptance criteria should state which fields and freshness matter for the receiving workflow. An API can return a valid schema while supplying a record that your team cannot use.

Use the [visitor evaluation kit](/resources/visitor-identification/) to record reviewed, accepted, rejected and unresolved output. Measure total operating cost against accepted records. Do not call a technical match rate a meeting rate, or a meeting rate an incremental revenue result.

## Geography and access are part of the contract

Document the regions and workflows the provider supports. Check the current [Leadpipe geography guidance](https://docs.leadpipe.com/guides/compliance-and-geography) and review the intended setup with your privacy owner. A result on eligible US traffic does not establish equivalent availability elsewhere.

Keep each client’s records within the intended organization and destination. For an agency or platform integration, inspect access boundaries with approved fixtures before scaling. See [multi-domain visitor tracking](/blog/multi-domain-visitor-tracking/) for the distinction between multiple websites, shared identity and client separation.

## A rollout your team can inspect

1. Select one site and one receiving workflow.
2. Verify account access and the supported collection method.
3. Retrieve a narrow date range and inspect the response structure.
4. Define acceptance and suppression rules with the team using the records.
5. Validate delivery, duplicates and failure handling using approved data.
6. Review one live cohort, then expand only after the output is useful.

Do not make an architecture decision from a vendor’s total graph size alone. The practical question is whether the API accepts your real input, returns the entity you need, and behaves predictably in your workflow.

## FAQ

### Is an identity resolution API the same as an enrichment API?

No. Enrichment adds information to a supported existing identifier. Identity resolution links identifiers or entities. A visitor product may expose resolved records through an API, while a customer platform may expose record-unification functions. Inspect the specific interface.

### Can I put a Leadpipe organization API key in browser JavaScript?

No. The official quickstart keeps the API key on your backend. Install the supplied browser pixel separately, without embedding the organization key.

### Does a returned business email prove the person visited?

No. A contact field alone does not establish the activity-to-person association. Check whether the record represents a matched visitor, company contact or enriched prospect.

### Do all integrations receive every visitor update?

No universal behavior should be assumed. Select and verify the delivery trigger, filters, entitlement and destination behavior for the actual product. Leadpipe webhooks distinguish First Match and Every Update.

## Evaluate the complete workflow

Review [Leadpipe Identification](/product/identification/), confirm the required delivery option in your [current plan](/pricing/), and use the scorecard on a real permitted cohort. The trial is **7 days or 500 profiles, whichever comes first, no card**. [Start a trial](https://dashboard.leadpipe.com/auth/signup).

## Sources and review basis

Published by Leadpipe. Vendor references support product descriptions; recommendations reflect our assessment of fit. Confirm current plan and contract terms before buying.

- [Leadpipe API quickstart](https://docs.leadpipe.com/api-reference/quickstart)
- [Authentication and errors](https://docs.leadpipe.com/api-reference/authentication-and-errors)
- [Set up webhooks](https://docs.leadpipe.com/guides/set-up-webhooks)
- [Understanding data quality](https://docs.leadpipe.com/guides/understanding-data-quality)
- [Geography and privacy](https://docs.leadpipe.com/guides/compliance-and-geography)

[Explore all comparisons and our evaluation method →](/compare/)