Bullion API

Bullion API provides real-time gold spot prices and historical data for developers. It offers cached price observations in over 150 currencies, a simple REST endpoint, and a free tier with 30 monthly requests. The service targets apps needing indicative valuations, charts, and market data without requiring credit cards.

Bullion API is listed with 7 APIs on the APIs.io network, including Bullion API API, Central Bank Gold API, Central Bank Reserves API, and 4 more. Tagged areas include Company, Gold, Prices, Finance, and Data.

The Bullion API catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

Bullion API’s developer surface includes pricing, documentation, and 23 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

37.5/100 thin ▼ -8.4 Agent 38/100 agent ready Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessFreemium

7 APIs

Company Gold Prices Finance Data

Kin Score

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

Composite quality — 37.5/100 · thin

Contract Quality 5.5 / 21

Developer Ergonomics 2.0 / 17

Access Clarity 10.5 / 17

Operational Transparency 2.0 / 11

Contract Governance 3.6 / 10

Discoverability 6.7 / 9

Regulatory Posture 4.0 / 15

Agent readiness — 38/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 0 / 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 6 / 6

Protected Resource Metadata 5 / 5

Registration Without a Human 6 / 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 does not apply to this provider. The published contracts declare no write operations, and a read-only API cannot create-or-update. The facet is excluded from this provider's denominator entirely — not scored zero. A reference or data API is not deficient for being unable to upsert.

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
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
Rate-Limit Signaling +7 pts — OpenAPI responses document X-RateLimit-* / RateLimit headers (verified), else a rate_limits artifact or RateLimits link (documented)

7 more unmet checks in the Agent Readiness table above.

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

Contract Quality scores 26.0 — up to +18.5 composite points
Developer Ergonomics scores 11.9 — up to +17.6 composite points
Operational Transparency scores 18.4 — up to +10.6 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/bullion-api/apis.yml: open an issue on github.com/api-evangelist/bullion-api 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 →

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.

OAuth 2.0 Protected Resource Metadata

measured — observed by APIs.io (verified)

Dynamic Client Registration

measured — observed by APIs.io (published)

OpenAPI

measured — observed by APIs.io (published)

APIs 7

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

Bullion API Bullion API API

The Bullion API API API from Bullion API — 3 operation(s) for bullion api api.

Bullion API Central Bank Gold API

The Central Bank Gold API from Bullion API — 1 operation(s) for central bank gold.

Bullion API Central Bank Reserves API

The Central Bank Reserves API from Bullion API — 1 operation(s) for central bank reserves.

Bullion API Countries API

The Countries API from Bullion API — 1 operation(s) for countries.

Bullion API Gold API

The Gold API from Bullion API — 1 operation(s) for gold.

Bullion API Portfolio API

The Portfolio API from Bullion API — 2 operation(s) for portfolio.

Bullion API Silver API

The Silver API from Bullion API — 1 operation(s) for silver.

Scroll for all 7

Bullion API pricing

Prices published by Bullion API, read 2026-10-14 from bullionapi.dev/pricing.

Plan	Price
Free	$0
Pro	$9/ mo
Business	$29/ mo

Plan details, limits and sources →

Billed by: subscription · FinOps profile →

Pricing Plans 2

Published pricing tiers and plan structures.

Bullion Api Plans Pricing

3 plans

PLANS

Bullion Api Price Estimates

0 plans

PLANS

Service Levels 1

Uptime the provider promises or reports, as SLA4OAI. Read from its own pages; APIs.io runs no monitors.

Bullion API

SLA

FinOps 1

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

Bullion Api Finops

FINOPS

Semantic Vocabularies 1

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

Bullion Api Context

8 classes · 18 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Bullion API API Rules

13 rules · 10 errors 1 warnings 2 info

SPECTRAL

JSON Schema 6

Standalone JSON Schema definitions for this provider's data models.

GetV1CentralBankGoldDeResponse

3 properties

JSON SCHEMA

GetV1CentralBankReservesGbResponse

7 properties

JSON SCHEMA

GetV1CountriesUkResponse

5 properties

JSON SCHEMA

GetV1GoldGoldidResponse

5 properties

JSON SCHEMA

GetV1SilverConsumptionResponse

6 properties

JSON SCHEMA

GetV1V1IdResponse

3 properties

JSON SCHEMA

Security Posture 2

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

Bullion Api Domain Security

TLSv1.3 · DMARC

SECURITY

Bullion Api Vulnerability Disclosure

security.txt · contact published

SECURITY

Resources

Get Started 2

Portal, sign-up, and the first successful call

Login

DeveloperPortal

DeveloperPortal

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

LLMsTxt

LLMsTxt

WellKnown

WellKnown

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

Spectral

JSONLD

Vocabulary

DataModel

Conformance

Build 1

SDKs, sample code, and the tooling you integrate with

Postman

Postman

Access & Security 6

Authentication, authorization, and security posture

Security

SecurityTxt

SecurityTxt

SecurityTxt

VulnerabilityDisclosure

VulnerabilityDisclosure

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

StatusPage

StatusPage

Commercial 4

Pricing, plans, and the legal terms of use

Plans

TermsOfService

PrivacyPolicy

Pricing

Company 1

The organization behind the API

Website

Website

Other 2

Properties that don't map to a standard resource type

Hosts

Hosts

Vendors

Vendors

Source (apis.yml)

aid: bullion-api
name: Bullion API
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: low
  probe_state: gated
  source:
  - plans
  - security
  generated: '2026-11-06'
  method: derived
image: https://bullionapi.dev/opengraph-image
description: Bullion API provides real-time gold spot prices and historical data for developers. It offers cached price observations
  in over 150 currencies, a simple REST endpoint, and a free tier with 30 monthly requests. The service targets apps needing
  indicative valuations, charts, and market data without requiring credit cards.
url: https://raw.githubusercontent.com/api-evangelist/bullion-api/refs/heads/main/apis.yml
x-type: company
x-source: harvest:new-submission
x-tier: profiled
x-tier-reason: enrichment pass 2026-10-14 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-10-14'
modified: '2026-10-14'
tags:
- Company
- Gold
- Prices
- Finance
- Data
tags_raw:
- Company
- Gold
- Prices
- API
- Finance
- Data
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Plans
  url: plans/bullion-api-plans-pricing.yml
- type: Spectral
  url: rules/bullion-api-rules.yml
- type: JSONLD
  url: json-ld/bullion-api-context.jsonld
- type: Vocabulary
  url: vocabulary/bullion-api-vocabulary.yml
- type: DataModel
  url: data-model/bullion-api-data-model.yml
- type: Security
  url: security/bullion-api-vulnerability-disclosure.yml
- type: Conformance
  url: conformance/bullion-api-conformance.yml
- type: LLMsTxt
  url: llms/bullion-api-llms.txt
- type: SecurityTxt
  url: well-known/bullion-api-status-security.txt
- type: SecurityTxt
  url: well-known/bullion-api-security.txt
- type: SecurityTxt
  url: well-known/bullion-api-api-security.txt
- type: WellKnown
  url: well-known/bullion-api-well-known.yml
- type: Hosts
  url: hosts/bullion-api-hosts.yml
- type: Vendors
  url: vendors/bullion-api-vendors.yml
- type: TermsOfService
  url: https://bullionapi.dev/terms
- type: StatusPage
  url: https://status.bullionapi.dev/
- type: PrivacyPolicy
  url: https://bullionapi.dev/privacy
- type: Pricing
  url: https://bullionapi.dev/pricing
- type: Postman
  url: https://god.gw.postman.com/run-collection/678099-be195d32-b9c5-469d-9d24-38af8bc946d6
- type: Login
  url: https://bullionapi.dev/login
- type: DeveloperPortal
  url: https://api.bullionapi.dev`
- type: VulnerabilityDisclosure
  url: security/bullion-api-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/bullion-api-domain-security.yml
- type: Website
  url: https://bullionapi.dev
- type: Documentation
  url: https://bullionapi.dev/docs
apis:
- aid: bullion-api:bullion-api-bullion-api-api-api
  name: Bullion API Bullion API API
  description: The Bullion API API API from Bullion API — 3 operation(s) for bullion api api.
  humanURL: https://bullionapi.dev/docs.md
  baseURL: https://api.bullionapi.dev
  tags:
  - Bullion API API
  properties:
  - type: OpenAPI
    url: openapi/bullion-api-bullion-api-api-api-openapi.yml
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-silver-consumption-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-central-bank-gold-de-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-v1-id-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-central-bank-reserves-gb-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-gold-goldid-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-countries-uk-response-schema.json
- aid: bullion-api:bullion-api-central-bank-gold-api
  name: Bullion API Central Bank Gold API
  description: The Central Bank Gold API from Bullion API — 1 operation(s) for central bank gold.
  humanURL: https://bullionapi.dev/docs.md
  baseURL: https://api.bullionapi.dev
  tags:
  - Central Bank Gold
  properties:
  - type: OpenAPI
    url: openapi/bullion-api-central-bank-gold-api-openapi.yml
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-silver-consumption-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-central-bank-gold-de-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-v1-id-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-central-bank-reserves-gb-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-gold-goldid-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-countries-uk-response-schema.json
- aid: bullion-api:bullion-api-central-bank-reserves-api
  name: Bullion API Central Bank Reserves API
  description: The Central Bank Reserves API from Bullion API — 1 operation(s) for central bank reserves.
  humanURL: https://bullionapi.dev/docs.md
  baseURL: https://api.bullionapi.dev
  tags:
  - Central Bank Reserves
  properties:
  - type: OpenAPI
    url: openapi/bullion-api-central-bank-reserves-api-openapi.yml
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-silver-consumption-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-central-bank-gold-de-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-v1-id-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-central-bank-reserves-gb-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-gold-goldid-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-countries-uk-response-schema.json
- aid: bullion-api:bullion-api-countries-api
  name: Bullion API Countries API
  description: The Countries API from Bullion API — 1 operation(s) for countries.
  humanURL: https://bullionapi.dev/docs.md
  baseURL: https://api.bullionapi.dev
  tags:
  - Countries
  properties:
  - type: OpenAPI
    url: openapi/bullion-api-countries-api-openapi.yml
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-silver-consumption-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-central-bank-gold-de-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-v1-id-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-central-bank-reserves-gb-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-gold-goldid-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-countries-uk-response-schema.json
- aid: bullion-api:bullion-api-gold-api
  name: Bullion API Gold API
  description: The Gold API from Bullion API — 1 operation(s) for gold.
  humanURL: https://bullionapi.dev/docs.md
  baseURL: https://api.bullionapi.dev
  tags:
  - Gold
  properties:
  - type: OpenAPI
    url: openapi/bullion-api-gold-api-openapi.yml
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-silver-consumption-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-central-bank-gold-de-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-v1-id-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-central-bank-reserves-gb-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-gold-goldid-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-countries-uk-response-schema.json
- aid: bullion-api:bullion-api-portfolio-api
  name: Bullion API Portfolio API
  description: The Portfolio API from Bullion API — 2 operation(s) for portfolio.
  humanURL: https://bullionapi.dev/docs.md
  baseURL: https://api.bullionapi.dev
  tags:
  - Portfolio
  properties:
  - type: OpenAPI
    url: openapi/bullion-api-portfolio-api-openapi.yml
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-silver-consumption-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-central-bank-gold-de-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-v1-id-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-central-bank-reserves-gb-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-gold-goldid-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-countries-uk-response-schema.json
- aid: bullion-api:bullion-api-silver-api
  name: Bullion API Silver API
  description: The Silver API from Bullion API — 1 operation(s) for silver.
  humanURL: https://bullionapi.dev/docs.md
  baseURL: https://api.bullionapi.dev
  tags:
  - Silver
  properties:
  - type: OpenAPI
    url: openapi/bullion-api-silver-api-openapi.yml
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-silver-consumption-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-central-bank-gold-de-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-v1-id-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-central-bank-reserves-gb-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-gold-goldid-response-schema.json
  - type: JSONSchema
    url: json-schema/bullion-api-get-v1-countries-uk-response-schema.json
x-submission-notes: Gold spot-price API with docs and first-party contact
x-submission-probe: root 200, docs 200; soft-404 ok
x-submitted-by: hello@bullionapi.dev (apis.io/add, 2026-10-13)
x-coverage:
  state: gated
  reason: partner-login
  method: derived
  generated: '2026-10-14'
  generator: derive-coverage.py (pre-flight evidence)
  detail: the company serves an API surface but requires credentials before any description of it can be read
  evidence:
  - url: https://bullionapi.dev/openapi.json
    status: null
  - url: https://api.bullionapi.dev/openapi.json
    status: null
  - url: https://status.bullionapi.dev/openapi.json
    status: null
  - url: https://api.bullionapi.dev/mcp
    status: 401
  - url: https://bullionapi.dev
    status: 200
x-enrichment:
  date: '2026-10-14'
  status: enriched
  artifacts_added: 31
  pass: modular-v1
  engine: identity=local,contract=local,surfaces=local,docs=local,regulatory=local

Bullion API — frequently asked questions

Does Bullion API have an API?

Yes. APIs.io lists 7 APIs from Bullion API, including Bullion API Bullion API API, Bullion API Central Bank Gold API and Bullion API Central Bank Reserves API, and 4 more.

Is there an OpenAPI specification for the Bullion API?

Yes. APIs.io indexes 7 OpenAPI specifications for Bullion API, each linked for download from this page.

How much does the Bullion API cost?

Bullion API publishes its prices; its Free plan is $0 as of 2026-10-14. APIs.io lists 3 pricing plans for Bullion API, with each plan's price, limits and inclusions under Pricing on this page.

Is the Bullion API ready for AI agents?

Bullion API has a Kin Score of 37.5 out of 100 (thin) and an Agent Readiness score of 38.0 (agent-ready), scored by API Evangelist on 2026-11-06.

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