Mayfield Fund
Mayfield Fund is an early-stage venture capital firm founded in 1969 and headquartered on Sand Hill Road in Menlo Park, California, with a presence in Mumbai, India. One of the oldest continuously active Silicon Valley firms, Mayfield describes itself as "people first, from inception" and reports that roughly 70% of its investments begin at company inception, positioning it as the first institutional investor for early-stage founders. The firm invests primarily at the Seed, Series A, and Series B stages across artificial intelligence, enterprise software, cloud and cybersecurity infrastructure, semiconductors, consumer and social commerce, and human and planetary health. Mayfield reports approximately $3B in assets under management (and states it has committed $3B to AI investments), has backed more than 550 companies over its history, and counts 120+ IPOs and 225+ M&A exits including Genentech, Lyft, HashiCorp, Poshmark, Marketo, Couchbase, SolarCity, Intuitive Surgical, and Compaq. In 2023 the firm raised $955M across two new funds dedicated to early-stage investing.
Mayfield Fund has 141 portfolio companies tracked on the APIs.io network, of which 52 (37%) publish APIs indexed here. The remaining 89 are tracked as profiles without a published API on the network.
Its highest-rated API providers on the network are Outreach, Big Panda, F5, Centrify, Storsimple.
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 5 Complete, well-documented, and agent-ready
Strong 9 Solid coverage with minor gaps
Developing 14 Usable, with meaningful gaps to close
Thin 12 Limited public surface area
Emerging 12 Early or largely undocumented
Properties
Portfolio
Where the firm publishes its investments
Content
Blog, podcast, newsletter, and research
Firm
The firm itself
Cohort brief
Auto-generatedThe 106 portfolio companies with APIs in the catalog, backed by Mayfield Fund, scored on the Kin Score. Every figure below is computed from the catalog — nothing here is written.
| Facet | This cohort | Catalog | Difference | Scored |
|---|---|---|---|---|
| Access Clarity | 32.1 | 26.5 | +5.6 | 106 |
| Developer Ergonomics | 28 | 23.8 | +4.2 | 106 |
| Discoverability | 58.9 | 58 | +0.9 | 106 |
| Contract Governance | 7.1 | 7 | +0.1 | 106 |
| Contract Quality | 17.6 | 17.7 | -0.1 | 106 |
| Operational Transparency | 13.1 | 13.2 | -0.1 | 106 |
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) | 20% | 15% | +5 |
| MCP server (first-party) | 19% | 13% | +6 |
| Agent Skills | 0% | 0% | 0 |
| OAuth scopes | 14% | 12% | +2 |
| Security | 95% | 98% | -3 |
| Arazzo workflows | 2% | 2% | 0 |
| 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 Outreach
- 2 BigPanda
- 3 F5
- 4 Delinea
- 5 Microsoft
- 6 Couchbase
- 7 InfluxData
- 8 Scrunch AI
- 9 Cube
- 10 SambaNova Systems
- 1 Scrunch AI {"score" => 59.2, "band" => "agent-ready"}
- 2 Outreach {"score" => 53.1, "band" => "agent-ready"}
- 3 Delinea {"score" => 50.6, "band" => "agent-ready"}
- 4 BigPanda {"score" => 50, "band" => "agent-ready"}
- 5 F5 {"score" => 47.4, "band" => "agent-ready"}
- 6 Revefi {"score" => 44.8, "band" => "agent-ready"}
- 7 Alchemy {"score" => 43.2, "band" => "agent-ready"}
- 8 Basis {"score" => 42.2, "band" => "agent-ready"}
- 9 Lyft {"score" => 37.1, "band" => "agent-ready"}
- 10 Cube {"score" => 36.5, "band" => "agent-ready"}
Coverage caveat. 94 of 106 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)
Work with this as data
Every firm here is available over the APIs.io API and to AI agents over MCP.