Circle Pharma

Circle Pharma is a clinical-stage biopharmaceutical company in South San Francisco, California, developing cell-permeable, orally bioavailable macrocycle therapies for cancer. Founded in 2013 by Matthew P. Jacobson and Scott Lokey out of work on predicting synthetic macrocycle cell permeability, the company applies its proprietary MXMO structure-based design platform to protein-protein interactions that conventional small molecules cannot reach. Its pipeline targets cyclins, the regulators of the cell cycle that drive many cancers: lead program CID-078, a first-in-class oral cyclin A/B RxL inhibitor, is in Phase 1 for advanced solid tumors, followed by a preclinical cyclin D1 RxL inhibitor and undisclosed cyclin programs partnered with Boehringer Ingelheim. Circle Pharma closed a $90M Series D led by The Column Group in 2024 and has an agreement with Eli Lilly to use Lilly TuneLab to strengthen the AI/ML side of the MXMO platform. Circle Pharma runs no developer program and publishes no product API; the only machine-readable surface it exposes is the anonymously readable WordPress REST content API behind circlepharma.com.

Circle Pharma publishes 10 APIs on the APIs.io network, including Categories API, Comments API, Discovery API, and 7 more. Tagged areas include Company, Biotechnology, Pharmaceuticals, Oncology, and Drug Discovery.

Circle Pharma’s developer surface includes engineering blog, support, authentication, and 23 more developer resources.

🌐 Visit website 📡 Source on GitHub

22.3/100 emerging ▬ flat Agent 22/100 agent aware saas Full breakdown ↓
scored 2026-09-14 · rubric v0.22.0

10 APIs

Company Biotechnology Pharmaceuticals Oncology Drug Discovery Macrocycles Clinical Trials Life Sciences content-api

Kin Score

Kin Score How this is scored →
scored 2026-09-14 · rubric v0.22.0

Composite quality — 22.3/100 · emerging

Contract Quality 2.8 / 21

Developer Ergonomics 3.5 / 17

Access Clarity 3.6 / 17

Operational Transparency 0.0 / 11

Contract Governance 0.5 / 10

Discoverability 6.9 / 9

Regulatory Posture 4.7 / 15

Agent readiness — 22/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 6 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 9 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 0 / 6

Agent Skills 5 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 4 / 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 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 does not apply to this provider. The published contracts declare no write operations, and a read-only API cannot create-or-update. The facet is excluded from this provider's denominator entirely — not scored zero. A reference or data API is not deficient for being unable to upsert.

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/circle-pharma: 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 →

APIs 10

Individual APIs this provider publishes, each with its own machine-readable definition.

Circle Pharma Categories API

Post categories

Circle Pharma Comments API

Comments on posts

Circle Pharma Discovery API

Route index, content types, taxonomies and statuses

Circle Pharma Events API

Upcoming and past events

Circle Pharma Media API

Media library items

Circle Pharma Pages API

Static site pages (pipeline, science, clinical trials)

Circle Pharma Posts API

Press releases, publications and in-the-news items

Circle Pharma Search API

Cross-content search

Circle Pharma Tags API

Post tags

Circle Pharma Team API

Leadership, board and team member records

Scroll for all 10

Open Collections 1

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

Circle Pharma Content API (WordPress REST API)

OPEN COLLECTION

Security Posture 2

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

Circle Pharma Authentication

http · 1 scheme

SECURITY

Circle Pharma Domain Security

TLSv1.3 · DMARC

SECURITY

Resources

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

WellKnown

WellKnown

LLMsTxt

LLMsTxt

AgentSkill

AgentSkill

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

Conventions

Conformance

ErrorCatalog

Lifecycle

DataModel

Access & Security 2

Authentication, authorization, and security posture

Authentication

Authentication

DomainSecurity

DomainSecurity

Operate 3

Status, limits, changes, and where to get help

PressReleases

PressReleases

Contact

Contact

Support

Support

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 7

The organization behind the API

Website

About

Blog

BlogRSS

Careers

Investors

LinkedIn

Scroll for all 7

Other 4

Properties that don't map to a standard resource type

Overlay

Publications

Events

SecondaryMarket

Source (apis.yml)

aid: circle-pharma
name: Circle Pharma
description: 'Circle Pharma is a clinical-stage biopharmaceutical company in South San Francisco, California, developing cell-permeable,
  orally bioavailable macrocycle therapies for cancer. Founded in 2013 by Matthew P. Jacobson and Scott Lokey out of work
  on predicting synthetic macrocycle cell permeability, the company applies its proprietary MXMO structure-based design platform
  to protein-protein interactions that conventional small molecules cannot reach. Its pipeline targets cyclins, the regulators
  of the cell cycle that drive many cancers: lead program CID-078, a first-in-class oral cyclin A/B RxL inhibitor, is in Phase
  1 for advanced solid tumors, followed by a preclinical cyclin D1 RxL inhibitor and undisclosed cyclin programs partnered
  with Boehringer Ingelheim. Circle Pharma closed a $90M Series D led by The Column Group in 2024 and has an agreement with
  Eli Lilly to use Lilly TuneLab to strengthen the AI/ML side of the MXMO platform. Circle Pharma runs no developer program
  and publishes no product API; the only machine-readable surface it exposes is the anonymously readable WordPress REST content
  API behind circlepharma.com.'
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - authentication
  - security
  generated: '2026-09-03'
  method: derived
image: https://circlepharma.com/wp-content/uploads/2024/01/Asset-2@2x.png
url: https://raw.githubusercontent.com/api-evangelist/circle-pharma/refs/heads/main/apis.yml
x-type: company
x-source: harvest:secondary-market
x-tier: profiled
x-tier-reason: enriched
specificationVersion: '0.23'
created: '2026-08-01'
modified: '2026-08-01'
tags:
- Company
- Biotechnology
- Pharmaceuticals
- Oncology
- Drug Discovery
- Macrocycles
- Clinical Trials
- Life Sciences
- content-api
tags_raw:
- Company
- biotechnology
- pharmaceuticals
- oncology
- drug-discovery
- macrocycles
- clinical-trials
- life-sciences
- content-api
apis:
- aid: circle-pharma:circle-pharma-categories-api
  name: Circle Pharma Categories API
  description: Post categories
  humanURL: https://developer.wordpress.org/rest-api/
  baseURL: https://circlepharma.com/wp-json
  tags:
  - Categories
  properties:
  - type: OpenAPI
    url: openapi/circle-pharma-categories-api-openapi.yml
  - type: Authentication
    url: authentication/circle-pharma-authentication.yml
  - type: ErrorCatalog
    url: errors/circle-pharma-problem-types.yml
  - type: Conventions
    url: conventions/circle-pharma-conventions.yml
  - type: DataModel
    url: data-model/circle-pharma-data-model.yml
- aid: circle-pharma:circle-pharma-comments-api
  name: Circle Pharma Comments API
  description: Comments on posts
  humanURL: https://developer.wordpress.org/rest-api/
  baseURL: https://circlepharma.com/wp-json
  tags:
  - Comments
  properties:
  - type: OpenAPI
    url: openapi/circle-pharma-comments-api-openapi.yml
  - type: Authentication
    url: authentication/circle-pharma-authentication.yml
  - type: ErrorCatalog
    url: errors/circle-pharma-problem-types.yml
  - type: Conventions
    url: conventions/circle-pharma-conventions.yml
  - type: DataModel
    url: data-model/circle-pharma-data-model.yml
- aid: circle-pharma:circle-pharma-discovery-api
  name: Circle Pharma Discovery API
  description: Route index, content types, taxonomies and statuses
  humanURL: https://developer.wordpress.org/rest-api/
  baseURL: https://circlepharma.com/wp-json
  tags:
  - Discovery
  properties:
  - type: OpenAPI
    url: openapi/circle-pharma-discovery-api-openapi.yml
  - type: Authentication
    url: authentication/circle-pharma-authentication.yml
  - type: ErrorCatalog
    url: errors/circle-pharma-problem-types.yml
  - type: Conventions
    url: conventions/circle-pharma-conventions.yml
  - type: DataModel
    url: data-model/circle-pharma-data-model.yml
- aid: circle-pharma:circle-pharma-events-api
  name: Circle Pharma Events API
  description: Upcoming and past events
  humanURL: https://developer.wordpress.org/rest-api/
  baseURL: https://circlepharma.com/wp-json
  tags:
  - Event
  tags_raw:
  - Events
  properties:
  - type: OpenAPI
    url: openapi/circle-pharma-events-api-openapi.yml
  - type: Authentication
    url: authentication/circle-pharma-authentication.yml
  - type: ErrorCatalog
    url: errors/circle-pharma-problem-types.yml
  - type: Conventions
    url: conventions/circle-pharma-conventions.yml
  - type: DataModel
    url: data-model/circle-pharma-data-model.yml
- aid: circle-pharma:circle-pharma-media-api
  name: Circle Pharma Media API
  description: Media library items
  humanURL: https://developer.wordpress.org/rest-api/
  baseURL: https://circlepharma.com/wp-json
  tags:
  - Media
  properties:
  - type: OpenAPI
    url: openapi/circle-pharma-media-api-openapi.yml
  - type: Authentication
    url: authentication/circle-pharma-authentication.yml
  - type: ErrorCatalog
    url: errors/circle-pharma-problem-types.yml
  - type: Conventions
    url: conventions/circle-pharma-conventions.yml
  - type: DataModel
    url: data-model/circle-pharma-data-model.yml
- aid: circle-pharma:circle-pharma-pages-api
  name: Circle Pharma Pages API
  description: Static site pages (pipeline, science, clinical trials)
  humanURL: https://developer.wordpress.org/rest-api/
  baseURL: https://circlepharma.com/wp-json
  tags:
  - Pages
  properties:
  - type: OpenAPI
    url: openapi/circle-pharma-pages-api-openapi.yml
  - type: Authentication
    url: authentication/circle-pharma-authentication.yml
  - type: ErrorCatalog
    url: errors/circle-pharma-problem-types.yml
  - type: Conventions
    url: conventions/circle-pharma-conventions.yml
  - type: DataModel
    url: data-model/circle-pharma-data-model.yml
- aid: circle-pharma:circle-pharma-posts-api
  name: Circle Pharma Posts API
  description: Press releases, publications and in-the-news items
  humanURL: https://developer.wordpress.org/rest-api/
  baseURL: https://circlepharma.com/wp-json
  tags:
  - Posts
  properties:
  - type: OpenAPI
    url: openapi/circle-pharma-posts-api-openapi.yml
  - type: Authentication
    url: authentication/circle-pharma-authentication.yml
  - type: ErrorCatalog
    url: errors/circle-pharma-problem-types.yml
  - type: Conventions
    url: conventions/circle-pharma-conventions.yml
  - type: DataModel
    url: data-model/circle-pharma-data-model.yml
- aid: circle-pharma:circle-pharma-search-api
  name: Circle Pharma Search API
  description: Cross-content search
  humanURL: https://developer.wordpress.org/rest-api/
  baseURL: https://circlepharma.com/wp-json
  tags:
  - Search
  properties:
  - type: OpenAPI
    url: openapi/circle-pharma-search-api-openapi.yml
  - type: Authentication
    url: authentication/circle-pharma-authentication.yml
  - type: ErrorCatalog
    url: errors/circle-pharma-problem-types.yml
  - type: Conventions
    url: conventions/circle-pharma-conventions.yml
  - type: DataModel
    url: data-model/circle-pharma-data-model.yml
- aid: circle-pharma:circle-pharma-tags-api
  name: Circle Pharma Tags API
  description: Post tags
  humanURL: https://developer.wordpress.org/rest-api/
  baseURL: https://circlepharma.com/wp-json
  tags:
  - Tags
  properties:
  - type: OpenAPI
    url: openapi/circle-pharma-tags-api-openapi.yml
  - type: Authentication
    url: authentication/circle-pharma-authentication.yml
  - type: ErrorCatalog
    url: errors/circle-pharma-problem-types.yml
  - type: Conventions
    url: conventions/circle-pharma-conventions.yml
  - type: DataModel
    url: data-model/circle-pharma-data-model.yml
- aid: circle-pharma:circle-pharma-team-api
  name: Circle Pharma Team API
  description: Leadership, board and team member records
  humanURL: https://developer.wordpress.org/rest-api/
  baseURL: https://circlepharma.com/wp-json
  tags:
  - Team
  properties:
  - type: OpenAPI
    url: openapi/circle-pharma-team-api-openapi.yml
  - type: Authentication
    url: authentication/circle-pharma-authentication.yml
  - type: ErrorCatalog
    url: errors/circle-pharma-problem-types.yml
  - type: Conventions
    url: conventions/circle-pharma-conventions.yml
  - type: DataModel
    url: data-model/circle-pharma-data-model.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Overlay
  url: overlays/circle-pharma-content-overlay.yaml
- type: Website
  url: https://circlepharma.com/
- type: About
  url: https://circlepharma.com/about-us
- type: Blog
  url: https://circlepharma.com/whats-new
- type: BlogRSS
  url: https://circlepharma.com/feed/
- type: PressReleases
  url: https://circlepharma.com/press-releases
- type: Publications
  url: https://circlepharma.com/publications
- type: Events
  url: https://circlepharma.com/upcoming-events
- type: Careers
  url: https://circlepharma.com/work-with-us
- type: Contact
  url: https://circlepharma.com/contact-us
- type: Investors
  url: https://circlepharma.com/investors
- type: Support
  url: https://circlepharma.com/contact-us
- type: TermsOfService
  url: https://circlepharma.com/terms-of-use
- type: PrivacyPolicy
  url: https://circlepharma.com/privacy-policy
- type: LinkedIn
  url: https://www.linkedin.com/company/circle-pharma-inc-/
- type: SecondaryMarket
  url: https://forgeglobal.com/circle-pharma_stock/
- type: Authentication
  url: authentication/circle-pharma-authentication.yml
- type: Conventions
  url: conventions/circle-pharma-conventions.yml
- type: Conformance
  url: conformance/circle-pharma-conformance.yml
- type: ErrorCatalog
  url: errors/circle-pharma-problem-types.yml
- type: Lifecycle
  url: lifecycle/circle-pharma-lifecycle.yml
- type: DataModel
  url: data-model/circle-pharma-data-model.yml
- type: WellKnown
  url: well-known/circle-pharma-well-known.yml
- type: DomainSecurity
  url: security/circle-pharma-domain-security.yml
- type: LLMsTxt
  url: llms/circle-pharma-llms.txt
- type: AgentSkill
  url: skills/_index.yml
x-enrichment:
  date: '2026-08-01'
  status: enriched
  artifacts_added: 15
  pass: local-v1

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