Fullseam

FullSeam builds AI agents for corporate accounting and finance operations teams, automating the manual work that happens outside traditional accounting software. Its agents handle accounts receivable (following up on payments, generating requested documentation, and entering invoices into customer AP portals), accounts payable (extracting invoices from multiple sources, matching them against purchase orders and contracts, chasing vendors for missing information, and categorizing expenses before posting to the general ledger), cash application, and reconciliation. FullSeam integrates with existing systems including QuickBooks, Xero, NetSuite, Sage, Bill, Stripe, HubSpot, Salesforce, and PandaDoc rather than requiring a platform migration, flagging exceptions with full context for human review and maintaining audit logs for compliance. Founded by the team behind TaxProper (acquired by Opendoor), FullSeam is a Y Combinator Winter 2026 company.

Fullseam is profiled on the APIs.io network. Tagged areas include Company, Accounting, Finance, FinOps, and AI Agents.

Fullseam’s developer surface includes support and 13 more developer resources.

🌐 Visit website 📡 Source on GitHub

16.4/100 emerging ▬ flat Agent 0/100 human only saas Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

0 APIs

Company Accounting Finance FinOps AI Agents Accounts Payable Accounts Receivable Reconciliation Cash Application Automation Fintech

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 16.4/100 · emerging

Contract Quality 0.0 / 25

Developer Ergonomics 1.0 / 20

Access Clarity 8.7 / 20

Operational Transparency 1.7 / 13

Contract Governance 0.0 / 12

Discoverability 5.0 / 10

Agent readiness — 0/100 · human only

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/fullseam: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Security Posture 3

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Fullseam Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Fullseam Vulnerability Disclosure

Hackerone · contact published

SECURITY

Fullseam Trust Center

SOC 2 Type 1, SOC 2 Type 2, HIPAA

SECURITY

Resources

Get Started 1

Portal, sign-up, and the first successful call

Login

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Access & Security 5

Authentication, authorization, and security posture

Security

Security

Compliance

Compliance

TrustCenter

TrustCenter

VulnerabilityDisclosure

VulnerabilityDisclosure

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

Support

Support

Commercial 2

Pricing, plans, and the legal terms of use

PrivacyPolicy

PrivacyPolicy

TermsOfService

TermsOfService

Company 2

The organization behind the API

Website

Website

About

About

Other 2

Properties that don't map to a standard resource type

ParentCompany

ParentCompany

CaseStudies

CaseStudies

Source (apis.yml)

aid: fullseam
name: Fullseam
description: FullSeam builds AI agents for corporate accounting and finance operations teams, automating the manual work that
  happens outside traditional accounting software. Its agents handle accounts receivable (following up on payments, generating
  requested documentation, and entering invoices into customer AP portals), accounts payable (extracting invoices from multiple
  sources, matching them against purchase orders and contracts, chasing vendors for missing information, and categorizing
  expenses before posting to the general ledger), cash application, and reconciliation. FullSeam integrates with existing
  systems including QuickBooks, Xero, NetSuite, Sage, Bill, Stripe, HubSpot, Salesforce, and PandaDoc rather than requiring
  a platform migration, flagging exceptions with full context for human review and maintaining audit logs for compliance.
  Founded by the team behind TaxProper (acquired by Opendoor), FullSeam is a Y Combinator Winter 2026 company.
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: false
  label: Hosted service · you call their endpoint
  confidence: medium
  source:
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source: []
  generated: '2026-07-22'
  method: derived
image: https://fullseam.com/static/frontend/fullseam-icon.svg
url: https://raw.githubusercontent.com/api-evangelist/fullseam/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- y-combinator
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-19'
tags:
- Company
- Accounting
- Finance
- FinOps
- AI Agents
- Accounts Payable
- Accounts Receivable
- Reconciliation
- Cash Application
- Automation
- Fintech
apis: []
common:
- type: ParentCompany
  url: https://apis.io/providers/opendoor/
  name: Opendoor
  x-relationship: acquired
  x-evidence: Founded by the team behind TaxProper (acquired by Opendoor), FullSeam is a Y Combinator Winter 2026 company.
- type: Website
  url: https://fullseam.com
- type: About
  url: https://fullseam.com/about
- type: CaseStudies
  url: https://fullseam.com/case-studies
- type: Login
  url: https://app.fullseam.com
- type: Support
  url: https://fullseam.com/book
- type: PrivacyPolicy
  url: https://fullseam.com/privacy
- type: TermsOfService
  url: https://fullseam.com/terms
- type: GitHubOrganization
  url: https://github.com/FullSeam
- type: Security
  url: https://fullseam.com/security
- type: Compliance
  url: https://fullseam.com/security
- type: TrustCenter
  url: security/fullseam-trust-center.yml
- type: VulnerabilityDisclosure
  url: security/fullseam-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/fullseam-domain-security.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence

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