Start with a free source-backed Bitcoin answer.
Give California Bitcoin the real Bitcoin question first. The free Start Here call returns a deterministic answer, checks maintained coverage, and recommends the smallest safe next action. Pay only when the task genuinely needs evidence-grade verification, packaging, chronology, or deeper grounding.
Delegate Bitcoin research agent to agent.
A2A 1.0 · synchronous JSON-RPCDelegate a Bitcoin question.
A general-purpose agent can hand California Bitcoin a focused question and receive a direct source-backed structured response from the maintained knowledge system.
Ask what a historical source actually said.
Covered attribution questions use retained, integrity-checked primary-source dossiers. Uncovered attribution fails safely instead of substituting a generic topical answer.
Check prior evidence before repeating work.
Agents can compare a retained evidence checkpoint for free before deciding whether research needs to be rerun.
/a2a. It is intentionally synchronous and free. It does not advertise persistent tasks, streaming, push notifications, or paid A2A execution. Evidence-grade paid research continues through the existing MCP and HTTP Stripe MPP interfaces.Try California Bitcoin now.
Live free calls, safe paid previewsRun a free call to inspect the live structured response.
Use it when a Bitcoin answer needs evidence, not another search result.
Maintained, deterministic, primary-source-firstIs this Bitcoin claim actually supported?
Adjudicate a proposition against maintained evidence, including contradictions, caveats, source authority, locators, and temporal context when available.
Give another agent auditable support.
Retrieve structured Bitcoin evidence and provenance with exact locator-backed support distinguished from broader source-level support.
Build a sourced Bitcoin timeline.
Use maintained historical relationships when the sequence of protocol, technical, or historical events matters.
Ground a broader Bitcoin research task.
Assemble deterministic multi-topic context when a generic web research agent needs a Bitcoin-specific evidence layer before acting downstream.
Start free. Pay only for research.
Server prices are authoritativeDiscover scope, retrieve canonical knowledge, inspect source quality, and choose the right product before spending anything.
Use when a workflow needs adjudication, a structured evidence set, or source-backed chronology.
Use for multi-topic dossiers or up to 20 claims and questions in one research package.
Canonical demonstration problems.
24 high-value research casesThese are designed to expose the difference between generic retrieval and maintained Bitcoin verification. Each can be evaluated through the free layer before an authorized agent chooses a paid research product.
Product selection is explicit.
Selection never authorizes paymentDeterministic routing
Tasks are verify, evidence, chronology, dossier, batch, and learn. The response explains purpose, exact price, input, output, when not to use the product, and the free alternative.
Same decision through MCP
The selector is free and read-only. Product choice and permission to spend are separate decisions.
Copy, paste, integrate.
Standards first, no SDK requiredFree deterministic answer
Free canonical search
Remote Streamable HTTP
Generic workflow
Paid calls use Stripe MPP inline.
HTTP 402 is part of the protocol402 Payment Required.Read the WWW-Authenticate: Payment ... challenge. It contains the server-selected amount and a request-bound payment challenge.Every paid result carries a compact trust receipt.
Evidence summary, not a signatureThe trust receipt helps another agent judge a result without duplicating the full research payload. It distinguishes source-level citation readiness from the stronger exact-locator-backed state. Payment does not guarantee coverage, exact locators, independent confirmation, or a favorable verdict.
asOf and reverifyAfter when evidence is version-sensitiveAgent onboarding in nine steps.
From discovery to reuseWhen California Bitcoin is the wrong tool.
Use the narrowest authoritative systemUse a market-data API
For live Bitcoin prices and rapidly changing market quotes.
Use a node or chain API
For current transactions, balances, blocks, mempool state, and fee estimates.
Use current primary sources
For breaking developments that have not yet entered the maintained evidence layer.
Use ordinary search first
For broad web discovery. Call California Bitcoin when a specific Bitcoin proposition needs source-backed verification or structured evidence.