CapMAC Holdings

CapMAC Holdings Inc. (Capital Markets Assurance Corporation) was a New York-based holding company that provided financial guaranty and surety insurance for structured securities worldwide, primarily asset-backed securities, alongside structured financial solutions, advisory and structuring services, and investment management. Founded in 1973 and headquartered at 885 Third Avenue in New York City, it was a Canaan Partners portfolio company. MBIA Inc. acquired CapMAC Holdings in a stock swap valued at more than $500 million, completing the merger on February 17, 1998, after which CapMAC operated as an indirect wholly-owned MBIA subsidiary. Capital Markets Assurance Corporation was merged into MBIA Insurance Corporation during the third quarter of 2010 and ceased to exist as a separately licensed insurer. The company is defunct and operates no website, developer program, or API surface; the capmac.com domain is an unrelated parked domain listed for sale.

CapMAC Holdings is profiled on the APIs.io network. Tagged areas include Company, Financial Services, Insurance, Financial Guaranty, and Structured Finance.

📡 Source on GitHub

0.0/100 minimal Agent 0/100 human only Full breakdown ↓
scored 2026-09-25 · rubric v0.23.0

0 APIs

Company Financial Services InsuranceFinancial GuarantyStructured FinanceAsset-Backed SecuritiesDefunct Acquired

Kin Score

Kin Score How this is scored →
scored 2026-09-25 · rubric v0.23.0

Composite quality — 0.0/100 · minimal

Contract Quality 0.0 / 21

Developer Ergonomics 0.0 / 17

Access Clarity 0.0 / 17

Operational Transparency 0.0 / 11

Contract Governance 0.0 / 10

Discoverability 0.0 / 9

Regulatory Posture 0.0 / 15

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

Regulatory Posture applies to this provider. Its tags matched the Insurance regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

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.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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/capmac: 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 →

Resources

Other 2

Properties that don't map to a standard resource type

CompanyProfile

CompanyProfile

Acquirer

Acquirer

Source (apis.yml)

aid: capmac
deliveryModel:
  model: unknown
  open_source: false
  commercial: false
  callable_host: false
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - none
  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://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/capmac.png
name: CapMAC Holdings
description: CapMAC Holdings Inc. (Capital Markets Assurance Corporation) was a New York-based holding company that provided
  financial guaranty and surety insurance for structured securities worldwide, primarily asset-backed securities, alongside
  structured financial solutions, advisory and structuring services, and investment management. Founded in 1973 and headquartered
  at 885 Third Avenue in New York City, it was a Canaan Partners portfolio company. MBIA Inc. acquired CapMAC Holdings in
  a stock swap valued at more than $500 million, completing the merger on February 17, 1998, after which CapMAC operated as
  an indirect wholly-owned MBIA subsidiary. Capital Markets Assurance Corporation was merged into MBIA Insurance Corporation
  during the third quarter of 2010 and ceased to exist as a separately licensed insurer. The company is defunct and operates
  no website, developer program, or API surface; the capmac.com domain is an unrelated parked domain listed for sale.
url: https://raw.githubusercontent.com/api-evangelist/capmac/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- canaan-partners
x-tier: stub
x-tier-reason: defunct-no-api-surface
x-status: defunct
x-founded: '1973'
x-headquarters: New York, New York, United States
x-acquired-by: MBIA Inc.
x-acquired-date: '1998-02-17'
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-20'
tags:
- Company
- Financial Services
- Insurance
- Financial Guaranty
- Structured Finance
- Asset-Backed Securities
- Defunct
- Acquired
tags_raw:
- Company
- Financial Services
- Insurance
- Financial Guaranty
- Structured Finance
- Asset-Backed Securities
- Defunct
- Acquired
- Financial-Services
apis: []
common:
- type: CompanyProfile
  url: https://www.canaan.com/companies/capmac-holdings
- type: Acquirer
  url: https://investor.mbia.com/investor-relations/corporate-profile/history/default.aspx
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
x-enrichment:
  date: '2026-07-20'
  status: nochange
  artifacts_added: 0
  pass: local-v1
  finding: Defunct entity, merged into MBIA Inc. 1998-02-17; CMAC dissolved into MBIA Insurance Corp Q3 2010. No live domain,
    developer portal, or API surface. capmac.com is a parked for-sale domain (HTTP 200, unrelated). No artifacts generated
    - no fabrication.

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