Tailcall

Tailcall is a high-performance GraphQL API gateway and runtime that lets developers compose multiple upstream REST, gRPC, and GraphQL APIs into a unified GraphQL schema. Built in Rust, it offers declarative configuration via .graphql files with directives for HTTP, caching, batching, and security controls. The open-source runtime (Apache 2.0) supports deployment on AWS Lambda, Cloudflare Workers, Docker, and bare metal. Tailcall Inc has subsequently shipped ForgeCode, a CLI coding harness built on the same performance-first ethos.

Tailcall is listed with 2 APIs on the APIs.io network. Tagged areas include GraphQL, API Gateway, GraphQL Runtime, REST, and gRPC.

The Tailcall catalog on APIs.io includes 1 JSON-LD context.

Tailcall’s developer surface includes documentation, engineering blog, and 9 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

26.3/100 thin ▬ flat Agent 14/100 agent aware Front door AI 2/6 trace Heartbeat 80/100 alive Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessFreemium

2 APIs

GraphQL API GatewayGraphQL RuntimeREST gRPC Rust Open Source API Composition CachingBatching

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 26.3/100 · thin

Contract Quality 9.7 / 21

Developer Ergonomics 2.8 / 17

Access Clarity 3.1 / 17

Operational Transparency 2.3 / 11

Contract Governance 0.0 / 10

Discoverability 4.9 / 9

Regulatory Posture 1.6 / 15

Agent readiness — 14/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) 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 could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

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/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey)
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0

11 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Developer Ergonomics scores 16.7 — up to +16.7 composite points
Access Clarity scores 18.4 — up to +16.3 composite points
Contract Quality scores 45.7 — up to +13.6 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

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 the provider profile at artifacts.apis.io/tailcall/apis.yml: open an issue on github.com/api-evangelist/tailcall to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Buf Schema Registry (public Protocol Buffers modules, gRPC / ConnectRPC schema publishers)	undeclared	-	-	-

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

Standards implemented 3

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

GraphQL

tagged — the provider's own APIs.json carries the standard as a tag; implementation not verified

gRPC

tagged — the provider's own APIs.json carries the standard as a tag; implementation not verified

REST

tagged — the provider's own APIs.json carries the standard as a tag; implementation not verified

APIs 2

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

Tailcall GraphQL Runtime

High-performance GraphQL runtime for composing multiple upstream REST, gRPC, and GraphQL APIs into a unified GraphQL schema. Configuration-driven via declarative .graphql files ...

ForgeCode API (Tailcall Inc)

ForgeCode is the commercial CLI coding harness product from Tailcall Inc, positioned as an AI-enabled programming assistant supporting 300+ models (Claude, GPT, Grok, Gemini, De...

GraphQL 1

GraphQL schemas published by this provider.

Tailcall GraphQL API

Tailcall is a high-performance GraphQL gateway and runtime built in Rust. It does not expose a fixed hosted GraphQL API endpoint — instead, it is a self-hosted runtime that deve...

GRAPHQL

Tailcall API pricing

Not yet checked against Tailcall's own pricing page. Compiled by API Evangelist on 2026-06-13; confirm before you rely on a figure. A free plan or tier is listed.

Plan	Price
Tailcall GraphQL Runtime (Open Source) open-source	Free
ForgeCode Free free	Free
ForgeCode Pro paid	$20
ForgeCode Max paid	$100

Plan details, limits and sources →

Pricing Plans 1

Published pricing tiers and plan structures.

Tailcall Plans Pricing

4 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Tailcall Rate Limits

0 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Tailcall Finops

FINOPS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Tailcall Context

32 classes · 11 properties

JSON-LD

Security Posture 1

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

Tailcall Domain Security

TLSv1.3 · DNSSEC · DMARC

SECURITY

Resources

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrg

GitHubOrg

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 2

Status, limits, changes, and where to get help

Discord

Discord

RateLimits

RateLimits

Commercial 2

Pricing, plans, and the legal terms of use

Plans

Plans

FinOps

FinOps

Company 3

The organization behind the API

Website

Website

LinkedIn

Blog

Blog

Other 1

Properties that don't map to a standard resource type

Source (apis.yml)

aid: tailcall
name: Tailcall
description: Tailcall is a high-performance GraphQL API gateway and runtime that lets developers compose multiple upstream
  REST, gRPC, and GraphQL APIs into a unified GraphQL schema. Built in Rust, it offers declarative configuration via .graphql
  files with directives for HTTP, caching, batching, and security controls. The open-source runtime (Apache 2.0) supports
  deployment on AWS Lambda, Cloudflare Workers, Docker, and bare metal. Tailcall Inc has subsequently shipped ForgeCode, a
  CLI coding harness built on the same performance-first ethos.
type: Index
deliveryModel:
  model: unknown
  open_source: unknown
  commercial: true
  callable_host: false
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - pricing
  - repository-unlicensed
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: low
  source:
  - plans
  - security
  - url: https://tailcall.run
    status: 301
    note: declared website redirects to https://forgecode.dev/ — a different registrable domain (tailcall.run -> forgecode.dev),
      possible rename or acquisition (probed 2026-09-03, roadmap#169)
  generated: '2026-11-06'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/tailcall.png
url: https://raw.githubusercontent.com/api-evangelist/tailcall/refs/heads/main/apis.yml
created: '2026-06-13'
modified: '2026-06-13'
specificationVersion: '0.23'
tags:
- GraphQL
- API Gateway
- GraphQL Runtime
- REST
- gRPC
- Rust
- Open Source
- API Composition
- Caching
- Batching
tags_raw:
- GraphQL
- API Gateway
- GraphQL Runtime
- REST
- gRPC
- Rust
- Open Source
- API Composition
- Caching
- Batching
- Open-Source
apis:
- aid: tailcall:tailcall-graphql-runtime
  name: Tailcall GraphQL Runtime
  description: High-performance GraphQL runtime for composing multiple upstream REST, gRPC, and GraphQL APIs into a unified
    GraphQL schema. Configuration-driven via declarative .graphql files with @server, @http, @upstream, @cache, and @batch
    directives. Provides automatic N+1 detection, HTTP caching, request batching, and static schema validation.
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://tailcall.run
  overlays: []
  contact: []
  properties:
  - type: Documentation
    url: https://tailcall.run/docs/
  - type: GitHubRepository
    url: https://github.com/tailcallhq/tailcall
  - type: OpenSource
    url: https://github.com/tailcallhq/tailcall/blob/main/LICENSE
  - type: ReleaseNotes
    url: https://github.com/tailcallhq/tailcall/releases
  - type: NPMPackage
    url: https://www.npmjs.com/package/@tailcallhq/tailcall
  - type: AWSDeployment
    url: https://github.com/tailcallhq/tailcall-on-aws
  - type: CLI
    url: https://tailcall.run/docs/guides/cli/
  - url: graphql/tailcall-graphql.md
    type: GraphQL
  tags:
  - GraphQL
  - API Gateway
  - Open Source
  - Rust
  - REST
  - gRPC
  tags_raw:
  - GraphQL
  - API Gateway
  - Open Source
  - Rust
  - REST
  - gRPC
  - Open-Source
- aid: tailcall:forgecode-api
  name: ForgeCode API (Tailcall Inc)
  description: ForgeCode is the commercial CLI coding harness product from Tailcall Inc, positioned as an AI-enabled programming
    assistant supporting 300+ models (Claude, GPT, Grok, Gemini, Deepseek, and more). Provides ZSH integration, multi-agent
    architecture (FORGE, MUSE, SAGE sub-agents), and large codebase context engines. Offers Free, Pro ($20/mo), and Max ($100/mo)
    tiers.
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  baseURL: https://forgecode.dev
  humanURL: https://forgecode.dev
  overlays: []
  contact: []
  properties:
  - type: Documentation
    url: https://forgecode.dev/docs/
  - type: GitHubRepository
    url: https://github.com/tailcallhq/forgecode
  - type: Pricing
    url: https://forgecode.dev/blog/graduating-from-early-access-new-pricing-tiers-available/
  - type: Blog
    url: https://forgecode.dev/blog/
  - type: Discord
    url: https://discord.gg/kRZBPpkgwq
  tags:
  - AI Coding
  - CLI
  - Multi-Model
  - Developer Tools
common:
- type: DomainSecurity
  url: security/tailcall-domain-security.yml
- type: Website
  url: https://tailcall.run
- type: Documentation
  url: https://tailcall.run/docs/
- type: GitHubOrg
  url: https://github.com/tailcallhq
- type: LinkedIn
  url: https://www.linkedin.com/company/tailcall
- type: Blog
  url: https://forgecode.dev/blog/
- type: X
  url: https://x.com/tailcallhq
- type: Discord
  url: https://discord.gg/kRZBPpkgwq
- type: Plans
  url: plans/tailcall-plans-pricing.yml
- type: RateLimits
  url: rate-limits/tailcall-rate-limits.yml
- type: FinOps
  url: finops/tailcall-finops.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

Tailcall API — frequently asked questions

Does Tailcall have an API?

Yes. APIs.io lists 2 APIs from Tailcall, including Tailcall GraphQL Runtime and ForgeCode API (Tailcall Inc).

How much does the Tailcall API cost?

APIs.io lists 4 pricing plans for Tailcall, with each plan's price, limits and inclusions under Pricing on this page.

Is the Tailcall API ready for AI agents?

Tailcall has a Kin Score of 26.3 out of 100 (thin) and an Agent Readiness score of 13.6 (agent-aware), scored by API Evangelist on 2026-11-06.

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