Zag Bio

Zag Bio is a clinical-stage biotechnology company developing thymus-targeted therapies for autoimmune diseases. The company engineers bifunctional antibodies that deliver self-antigens to antigen-presenting cells in the thymus, harnessing the body's natural process of central immune tolerance so developing immune cells learn to recognize, tolerate, and protect the body's own tissues. Its pipeline includes ZAG-101, a candidate for Type 1 Diabetes. Founded and incubated by Polaris Partners, Zag Bio launched publicly in October 2025 with an $80M Series A. It is tracked in the API Evangelist network as a Lightspeed Venture Partners portfolio company; as a therapeutics developer it publishes no public API or developer platform at this time.

Zag Bio is profiled on the APIs.io network. Tagged areas include Company, Biotechnology, Pharmaceuticals, Autoimmune, and Immunology.

Zag Bio’s developer surface includes engineering blog, support, and 3 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

9.6/100 minimal ▬ flat Agent 0/100 human only Front door AI 1/6 silent Heartbeat 100/100 alive saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessNo public API

0 APIs

Company Biotechnology Pharmaceuticals Autoimmune Immunology Therapeutics Drug Development Healthcare

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 9.6/100 · minimal

Contract Quality 0.0 / 21

Developer Ergonomics 1.2 / 17

Access Clarity 3.6 / 17

Operational Transparency 0.0 / 11

Contract Governance 0.0 / 10

Discoverability 4.1 / 9

Regulatory Posture 0.9 / 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

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Health 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/.

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Agent readiness — checks not met, largest first (exact, from this profile):

Machine-Readable Contract +18 pts — api_specs includes an OpenAPI document
MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey)
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes

13 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 0.0 — up to +25.0 composite points
Developer Ergonomics scores 7.1 — up to +18.6 composite points
Access Clarity scores 21.1 — up to +15.8 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

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 the provider profile at artifacts.apis.io/zag-bio/apis.yml: open an issue on github.com/api-evangelist/zag-bio to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
VC Portfolios (a16z, Battery Ventures, Sequoia Capital, Index Ventures participation)	undeclared	-	-	-

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

Resources

Operate 1

Status, limits, changes, and where to get help

Support

Support

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 2

The organization behind the API

Website

Website

Blog

Blog

Source (apis.yml)

aid: zag-bio
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
  gated: private
  gated_source:
  - x-api-posture
  label: Unknown
  confidence: low
  source: []
  generated: '2026-11-06'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/zag-bio.png
name: Zag Bio
description: Zag Bio is a clinical-stage biotechnology company developing thymus-targeted therapies for autoimmune diseases.
  The company engineers bifunctional antibodies that deliver self-antigens to antigen-presenting cells in the thymus, harnessing
  the body's natural process of central immune tolerance so developing immune cells learn to recognize, tolerate, and protect
  the body's own tissues. Its pipeline includes ZAG-101, a candidate for Type 1 Diabetes. Founded and incubated by Polaris
  Partners, Zag Bio launched publicly in October 2025 with an $80M Series A. It is tracked in the API Evangelist network as
  a Lightspeed Venture Partners portfolio company; as a therapeutics developer it publishes no public API or developer platform
  at this time.
url: https://raw.githubusercontent.com/api-evangelist/zag-bio/refs/heads/main/apis.yml
x-api-posture: no-product-api
x-api-posture-basis: observed
x-api-posture-note: It is tracked in the API Evangelist network as a Lightspeed Venture Partners portfolio company; as a therapeutics
  developer it publishes no public API or developer platform at this time.
x-type: company
x-source: vc-portfolio
x-backed-by:
- lightspeed-venture-partners
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-21'
tags:
- Company
- Biotechnology
- Pharmaceuticals
- Autoimmune
- Immunology
- Therapeutics
- Drug Development
- Healthcare
tags_raw:
- Company
- Biotechnology
- Pharmaceuticals
- Autoimmune
- Immunology
- Therapeutics
- Drug Development
- Healthcare
- Venture Backed
apis: []
common:
- type: Website
  url: https://zagbio.com/
- type: Blog
  url: https://zagbio.com/news-resources/
- type: Support
  url: https://zagbio.com/contact/contact-us/
- type: TermsOfService
  url: https://zagbio.com/terms-of-use
- type: PrivacyPolicy
  url: https://zagbio.com/privacy-policy/
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
x-enrichment:
  date: '2026-07-21'
  status: minimal
  artifacts_added: 0
  pass: local-v1

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