Upstream Bio
Upstream Bio is a clinical-stage biotechnology company headquartered at 460 Totten Pond Road in Waltham, Massachusetts, founded in 2021 and listed on Nasdaq as UPB since its October 2024 IPO. The company develops treatments for inflammatory disease with an initial focus on severe respiratory disorders, and its strategy is built around a single lead asset: verekitug (UPB-101), described by the company as the only known antagonist in clinical development that targets the receptor for thymic stromal lymphopoietin (TSLP). Verekitug has been advanced into Phase 2 studies in severe asthma, chronic rhinosinusitis with nasal polyps (CRSwNP) and chronic obstructive pulmonary disease (COPD), with a Phase 3 development strategy announced in 2026. Upstream Bio is a therapeutics developer rather than a software vendor: upstreambio.com is a fourteen-page WordPress marketing site, investor material is served from a hosted Q4-style investor-relations subdomain, and the company publishes no developer program, no public API, no SDK and no machine-readable API contract.
Index entry only — little beyond a description and a link, and nothing machine-readable enough for an agent to act on without a human reading the site first.
API Evangelist profiles Upstream Bio the way a machine reads it — 1 machine-readable artifact, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Upstream Bio scores 10.5/100 (minimal), with a separate agent-readiness read of 0/100 (human only). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Why this profile is thin
Upstream Bio is a Nasdaq-listed clinical-stage drug developer whose product is a single therapeutic program (verekitug, an anti-TSLP-receptor antibody in Phase 2/3); upstreambio.com is a fourteen-page WordPress marketing site with no /developers, /docs or /api path at all, the investor material lives on a hosted IR subdomain, and the only machine-readable endpoints on either host are the CMS defaults — an RSS feed, a Yoast sitemap, and WordPress core's undocumented, noindexed /wp-json/ route index — rather than any published product API.
This is an honest zero, not a gap in our research. Upstream Bio does not appear to expose an API, so there is nothing here for us to index and nothing for them to fix.
What we probed
https://upstreambio.com/→ HTTP 200https://upstreambio.com/openapi.json→ HTTP 404https://upstreambio.com/swagger.json→ HTTP 404https://upstreambio.com/graphql→ HTTP 404https://upstreambio.com/llms.txt→ HTTP 404https://upstreambio.com/.well-known/api-catalog→ HTTP 404https://upstreambio.com/.well-known/agent-card.json→ HTTP 404https://upstreambio.com/.well-known/agent.json→ HTTP 404https://investors.upstreambio.com/llms.txt→ HTTP 404https://investors.upstreambio.com/.well-known/api-catalog→ HTTP 404https://upstreambio.com/wp-json/→ HTTP 200
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance. Every facet and dimension name is a link: it opens that measurement's page on APIs.io, where the rating runs across the whole catalog — the exact checks that feed it, how every profiled provider distributes on it, and who is at the top of it.
Kin Score
How this is scored →scored 2026-09-02 · rubric v0.18.0
Put this on your own site. The badge is drawn live from Upstream Bio's current Kin Score — paste it once and it updates itself every time the score is recomputed. It follows your visitor's light or dark setting, and it links back here so anyone who sees it can read the full breakdown.
<!-- Kin Score · API Evangelist -->
<a href="https://providers.apievangelist.com/providers/upstream-bio/"
title="Upstream Bio on API Evangelist — API profile and Kin Score">
<img src="https://apis.io/badge/upstream-bio.svg"
alt="Upstream Bio Kin Score — API readiness rating by API Evangelist" width="150" height="150" loading="lazy">
</a>[](https://providers.apievangelist.com/providers/upstream-bio/)<!-- Kin Score · API Evangelist -->
<a href="https://providers.apievangelist.com/providers/upstream-bio/"
title="Upstream Bio on API Evangelist — API profile and Kin Score">
<img src="https://apis.io/badge/upstream-bio/card.svg"
alt="Upstream Bio Kin Score — API readiness rating by API Evangelist" width="340" height="120" loading="lazy">
</a>More shapes, themes and sizes → · Score as JSON · How badges work
How we profile Upstream Bio
Each block below is one kind of artifact we hold for Upstream Bio. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
Security Posture 1
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Resources
Every other property we hold for Upstream Bio — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Agent Surfaces 1
MCP servers, agent skills, and machine-readable catalogs
Access & Security 1
Authentication, authorization, and security posture
Operate 1
Status, limits, changes, and where to get help
Commercial 2
Pricing, plans, and the legal terms of use
Company 6
The organization behind the API
← All providers · Data indexed from github.com/api-evangelist/upstream-bio · machine-readable index on apis.io
This is an independent, third-party profile of Upstream Bio, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.
The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.
Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.
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you will get a person, not a form — we will tell you exactly which public URLs this profile was built from.