Andreessen Horowitz
Andreessen Horowitz (a16z) is a Silicon Valley venture capital firm founded in July 2009 by Marc Andreessen and Ben Horowitz and headquartered in Menlo Park, California. The firm invests across the full lifecycle from seed to venture to growth-stage technology companies, deploying stage-based checks that range from roughly $1M-$5M into early application bets up to hundreds of millions of dollars into its largest AI positions. a16z organizes around dedicated practice areas: AI, American Dynamism, Bio + Healthcare, Consumer, Crypto, Enterprise, Fintech, Games, Infrastructure, plus specialty vehicles including the Cultural Leadership Fund, Perennial, and the Speedrun accelerator. With over $90B-$100B+ in assets under management as of early 2026 and a public portfolio of more than 1,000 companies, a16z is one of the largest and most influential venture firms in the world, known for its operator-led platform model and notable investments including Airbnb, Coinbase, GitHub, Figma, Stripe, Databricks, Anduril, and OpenAI.
Every Andreessen Horowitz company that ships an API, scored the way a machine reads it — and what the book says about the fund's real bet.
Andreessen Horowitz has 1,100 portfolio companies tracked on the APIs.io network, of which 1,097 (100%) publish APIs indexed here.
Its highest-rated API providers on the network are Stripe, Svix, OpenAI, Mux, Ghost.
Portfolio on the Network
Portfolio companies that publish APIs indexed on APIs.io, grouped by their API Evangelist rating. Exemplar and Strong are expanded by default.
Exemplar 16 Complete, well-documented, and agent-ready
Strong 44 Solid coverage with minor gaps
Developing 121 Usable, with meaningful gaps to close
Thin 148 Limited public surface area
Emerging 228 Early or largely undocumented
Minimal 527 Almost no public developer surface
Rest of Portfolio
3 further portfolio companies that don’t yet have a provider page on the network.
Scroll for all 3
Properties
Portfolio
Where the firm publishes its investments
Content
Blog, podcast, newsletter, and research
Firm
The firm itself
Cohort brief
Auto-generatedThe 1084 portfolio companies with APIs in the catalog, backed by Andreessen Horowitz, scored on the Kin Score. Every figure below is computed from the catalog — nothing here is written.
| Facet | This cohort | Catalog | Difference | Scored |
|---|---|---|---|---|
| Developer Ergonomics | 18.4 | 17.9 | +0.5 | 1084 |
| Operational Transparency | 10.6 | 11.3 | -0.7 | 1084 |
| Contract Governance | 5.4 | 6.4 | -1 | 1084 |
| Access Clarity | 20.2 | 22.3 | -2.1 | 1084 |
| Discoverability | 58.2 | 60.4 | -2.2 | 1084 |
| Contract Quality | 14.8 | 17.5 | -2.7 | 1084 |
A facet is averaged over the members that carry it, not over the whole cohort — the “Scored” column is that count. Averaging an absent facet as zero would score our own coverage gaps as the providers’ posture.
| Artifact | This cohort | Catalog | Difference |
|---|---|---|---|
| MCP server (any) | 19% | 16% | +3 |
| MCP server (first-party) | 7% | 7% | 0 |
| Agent Skills | 0% | 0% | 0 |
| OAuth scopes | 6% | 9% | -3 |
| Security | 74% | 88% | -14 |
| Arazzo workflows | 3% | 2% | +1 |
| Governance rules | 9% | 13% | -4 |
mcp_pct counts any mcp/ artifact including ones API Evangelist derived from the provider OpenAPI; mcp_first_party_pct counts only servers the provider publishes. Prefer the latter.
- 1 Stripe 83.2
- 2 Svix 79.2
- 3 Mux 75.4
- 4 Optimizely 75.1
- 5 Ghost 74.4
- 6 Twilio 73.4
- 7 Spade 73.1
- 8 Lightspark 71.4
- 9 MethodFi 71.4
- 10 Plaid 68.2
- 1 Zapier 61.5
- 2 Mem 61.3
- 3 Endgame 56.8
- 4 Wefunder 55.9
- 5 Equals 54.4
- 6 Figma 53.2
- 7 Lightspark 52.6
- 8 Sprig 52.3
- 9 Ripple Labs 51.8
- 10 Svix 49.9
Source (apis.yml)
Work with this as data
Every firm here is available over the APIs.io API and to AI agents over MCP.