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.
Andreessen Horowitz has 1,100 portfolio companies tracked on the APIs.io network, of which 372 (34%) publish APIs indexed here. The remaining 727 are tracked as profiles without a published API on the network.
Its highest-rated API providers on the network are Twilio, Plaid, OpenAI, Stripe, ElevenLabs.
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 27 Complete, well-documented, and agent-ready
Strong 43 Solid coverage with minor gaps
Developing 97 Usable, with meaningful gaps to close
Thin 118 Limited public surface area
Emerging 73 Early or largely undocumented
Minimal 14 Almost no public developer surface
Rest of Portfolio
1 further portfolio companies that don’t yet have a provider page on the network.
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Properties
Portfolio
Where the firm publishes its investments
Content
Blog, podcast, newsletter, and research
Firm
The firm itself
Cohort brief
Auto-generatedThe 761 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 | 26.4 | 23.8 | +2.6 | 761 |
| Operational Transparency | 14.8 | 13.2 | +1.6 | 761 |
| Access Clarity | 27.6 | 26.5 | +1.1 | 761 |
| Contract Quality | 18.1 | 17.7 | +0.4 | 761 |
| Discoverability | 58.3 | 58 | +0.3 | 761 |
| Contract Governance | 6.1 | 7 | -0.9 | 761 |
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) | 17% | 15% | +2 |
| MCP server (first-party) | 16% | 13% | +3 |
| Agent Skills | 0% | 0% | 0 |
| OAuth scopes | 9% | 12% | -3 |
| Security | 97% | 98% | -1 |
| Arazzo workflows | 4% | 2% | +2 |
| Governance rules | 14% | 18% | -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 Twilio
- 2 Plaid
- 3 OpenAI
- 4 Stripe
- 5 ElevenLabs
- 6 GitHub
- 7 Okta
- 8 Optimizely
- 9 Ghost
- 10 Doordash
- 1 Zapier {"score" => 66.2, "band" => "agent-ready"}
- 2 GitHub {"score" => 63.4, "band" => "agent-ready"}
- 3 Moov {"score" => 63.4, "band" => "agent-native"}
- 4 Optimizely {"score" => 62.9, "band" => "agent-ready"}
- 5 Webflow {"score" => 62.5, "band" => "agent-ready"}
- 6 Lumos {"score" => 60.3, "band" => "agent-ready"}
- 7 Mem {"score" => 59.6, "band" => "agent-native"}
- 8 Databricks {"score" => 58.9, "band" => "agent-ready"}
- 9 Netlify {"score" => 58.8, "band" => "agent-ready"}
- 10 Stripe {"score" => 58.5, "band" => "agent-native"}
Coverage caveat. 678 of 761 scored members had under half their catalog-attributable points satisfied at all (catalog_earned / catalog_max < 0.5). They are INCLUDED in the mean above. A large share here means the cohort mean is partly a measurement of how far our enrichment reached, not only of how these providers publish.Generated from the catalog build of 2 November 2026, across 37080 providers, using the same computation served by the APIs.io cohort API. Briefs are published for rosters of 5 or more scored providers; below that a distribution is not meaningful.
Source (apis.yml)
Compared on APIs.io
Side by side with another market, using the compare_cohorts tool: facet by facet, with the full tool response.
- vs Y Combinator Y Combinator vs Andreessen Horowitz: whose portfolio ships the better APIs?
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Work with this as data
Every firm here is available over the APIs.io API and to AI agents over MCP.