[
  {
    "source_id": "materials_project",
    "source_name": "Materials Project",
    "source_type": "database",
    "base_url": "https://materialsproject.org",
    "access_method": "official_api (mp-api)",
    "license_notes": "Data CC-BY-style; confirm current terms; requires API key.",
    "rate_limit_notes": "per API key",
    "trust_tier": 1,
    "last_verified_at": "2026-06-20",
    "notes": "Use official mp-api client, never scrape."
  },
  {
    "source_id": "nomad",
    "source_name": "NOMAD",
    "source_type": "database",
    "base_url": "https://nomad-lab.eu",
    "access_method": "rest_api / local_oasis",
    "license_notes": "FAIR data platform; per-entry licenses vary.",
    "rate_limit_notes": "see API docs",
    "trust_tier": 1,
    "last_verified_at": "2026-06-20",
    "notes": "Supports local Oasis deployment."
  },
  {
    "source_id": "nist_webbook",
    "source_name": "NIST Chemistry WebBook",
    "source_type": "database",
    "base_url": "https://webbook.nist.gov",
    "access_method": "metadata_only / controlled_mirror",
    "license_notes": "US Govt standard reference data; follow NIST usage terms.",
    "rate_limit_notes": "be polite; no bulk hammering",
    "trust_tier": 1,
    "last_verified_at": "2026-06-20",
    "notes": "Thermochemistry, spectra, ionization."
  },
  {
    "source_id": "pubchem",
    "source_name": "PubChem PUG REST",
    "source_type": "API",
    "base_url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug",
    "access_method": "official_api (PUG REST)",
    "license_notes": "Public domain (US NLM); attribution courteous.",
    "rate_limit_notes": "<=5 req/s guideline",
    "trust_tier": 1,
    "last_verified_at": "2026-06-20",
    "notes": "CID/SMILES/InChIKey/descriptors."
  },
  {
    "source_id": "aflow",
    "source_name": "AFLOW / AFLUX",
    "source_type": "database",
    "base_url": "http://aflowlib.org",
    "access_method": "rest_api (AFLUX)",
    "license_notes": "Confirm AFLOW data license.",
    "rate_limit_notes": "see API docs",
    "trust_tier": 3,
    "last_verified_at": "2026-06-20",
    "notes": "Record AUID/AURL for provenance."
  },
  {
    "source_id": "cod",
    "source_name": "Crystallography Open Database",
    "source_type": "database",
    "base_url": "https://www.crystallography.net",
    "access_method": "rest_entry / cif_download",
    "license_notes": "Open-access (mostly public domain / CC0); per-entry varies.",
    "rate_limit_notes": "be polite",
    "trust_tier": 2,
    "last_verified_at": "2026-06-20",
    "notes": "Fetch CIF by COD ID; hash structure."
  },
  {
    "source_id": "openalex",
    "source_name": "OpenAlex",
    "source_type": "index",
    "base_url": "https://api.openalex.org",
    "access_method": "official_api",
    "license_notes": "CC0 metadata; polite-pool via mailto.",
    "rate_limit_notes": "100k/day polite pool",
    "trust_tier": 3,
    "last_verified_at": "2026-06-20",
    "notes": "Index only; do not store full text."
  },
  {
    "source_id": "crossref",
    "source_name": "Crossref REST API",
    "source_type": "API",
    "base_url": "https://api.crossref.org",
    "access_method": "official_api",
    "license_notes": "Metadata open; polite-pool via mailto.",
    "rate_limit_notes": "polite pool",
    "trust_tier": 1,
    "last_verified_at": "2026-06-20",
    "notes": "DOI truth source + metadata normalizer."
  },
  {
    "source_id": "preprint_layer",
    "source_name": "arXiv + ChemRxiv + Semantic Scholar",
    "source_type": "preprint",
    "base_url": "https://arxiv.org",
    "access_method": "official_api / metadata",
    "license_notes": "Preprints NOT peer reviewed; respect each license.",
    "rate_limit_notes": "per-API",
    "trust_tier": 5,
    "last_verified_at": "2026-06-20",
    "notes": "evidence_level defaults to preprint_unreviewed; never auto-promote to fact."
  },
  {
    "source_id": "nature_materials",
    "source_name": "Nature Materials",
    "source_type": "journal",
    "base_url": "https://www.nature.com/nmat",
    "access_method": "rss_toc / crossref_metadata",
    "license_notes": "Full text copyrighted; store metadata/abstract/DOI/OA-link only.",
    "rate_limit_notes": "RSS polite",
    "trust_tier": 2,
    "last_verified_at": "2026-06-20",
    "notes": ""
  },
  {
    "source_id": "advanced_materials",
    "source_name": "Advanced Materials",
    "source_type": "journal",
    "base_url": "https://onlinelibrary.wiley.com/journal/15214095",
    "access_method": "rss_toc / crossref_metadata",
    "license_notes": "Copyrighted full text; metadata only.",
    "rate_limit_notes": "polite",
    "trust_tier": 2,
    "last_verified_at": "2026-06-20",
    "notes": ""
  },
  {
    "source_id": "adv_functional_materials",
    "source_name": "Advanced Functional Materials",
    "source_type": "journal",
    "base_url": "https://onlinelibrary.wiley.com/journal/16163028",
    "access_method": "rss_toc / crossref_metadata",
    "license_notes": "Copyrighted full text; metadata only.",
    "rate_limit_notes": "polite",
    "trust_tier": 2,
    "last_verified_at": "2026-06-20",
    "notes": ""
  },
  {
    "source_id": "progress_materials_science",
    "source_name": "Progress in Materials Science",
    "source_type": "journal",
    "base_url": "https://www.sciencedirect.com/journal/progress-in-materials-science",
    "access_method": "crossref_metadata",
    "license_notes": "Copyrighted reviews; metadata only.",
    "rate_limit_notes": "polite",
    "trust_tier": 2,
    "last_verified_at": "2026-06-20",
    "notes": "High-weight reviews; still claim-level citation."
  },
  {
    "source_id": "energy_environ_science",
    "source_name": "Energy & Environmental Science",
    "source_type": "journal",
    "base_url": "https://pubs.rsc.org/en/journals/journalissues/ee",
    "access_method": "rss_toc / crossref_metadata",
    "license_notes": "Copyrighted full text; metadata only.",
    "rate_limit_notes": "polite",
    "trust_tier": 2,
    "last_verified_at": "2026-06-20",
    "notes": ""
  },
  {
    "source_id": "chemistry_of_materials",
    "source_name": "Chemistry of Materials",
    "source_type": "journal",
    "base_url": "https://pubs.acs.org/journal/cmatex",
    "access_method": "rss_toc / crossref_metadata",
    "license_notes": "ACS copyrighted; metadata only.",
    "rate_limit_notes": "polite",
    "trust_tier": 2,
    "last_verified_at": "2026-06-20",
    "notes": ""
  },
  {
    "source_id": "acs_nano",
    "source_name": "ACS Nano",
    "source_type": "journal",
    "base_url": "https://pubs.acs.org/journal/ancac3",
    "access_method": "rss_toc / crossref_metadata",
    "license_notes": "ACS copyrighted; metadata only.",
    "rate_limit_notes": "polite",
    "trust_tier": 2,
    "last_verified_at": "2026-06-20",
    "notes": "Nano optical/colour/mechanical effects."
  },
  {
    "source_id": "jmca_b_c",
    "source_name": "Journal of Materials Chemistry A/B/C",
    "source_type": "journal",
    "base_url": "https://pubs.rsc.org/en/journals/journalissues/ta",
    "access_method": "rss_toc / crossref_metadata",
    "license_notes": "RSC copyrighted; metadata only.",
    "rate_limit_notes": "polite",
    "trust_tier": 2,
    "last_verified_at": "2026-06-20",
    "notes": "Route by A=energy, B=bio/soft, C=opto/electronic."
  },
  {
    "source_id": "acs_ami",
    "source_name": "ACS Applied Materials & Interfaces",
    "source_type": "journal",
    "base_url": "https://pubs.acs.org/journal/aamick",
    "access_method": "rss_toc / crossref_metadata",
    "license_notes": "ACS copyrighted; metadata only.",
    "rate_limit_notes": "polite",
    "trust_tier": 2,
    "last_verified_at": "2026-06-20",
    "notes": "Surfaces, interfaces, coatings, texture."
  }
]