Copper API by Copper

# Fix list: Copper API

From Anchor Terminal's listing at https://www.anchorterminal.com/tools/copper, the October 2026 research run, assessed 1 October 2026. Grade D, 46.9 out of 100.

This is everything the published grade says the listing lacks, the biggest possible gain to the total first. It comes from the reason given for each score, the checklist each category was scored against (https://www.anchorterminal.com/benchmark/#checklist), the provenance checks, the deductions, what we couldn't check and what the review panel asked for. A fix counts at the next check, once it's public.

For a coding agent working on Copper API: work through the items below in the product, its docs and its public pages. Each category gives the reason for its score, with the points each checklist item earned, and the checklist itself, so the gap is the items that earned less than their points. Change the product, not the wording, and keep a note of what you changed and where it's published.

## 1. Security & auth, 27 out of 100, up to 12.8 more on the total

Why it scored 27: Personal API keys sent in `X-PW-AccessToken` with the owner's email, carrying that user's full rights. Admins can see every user's keys. OAuth 2.0 exists for partner apps, but we found no scope list and no documented revocation (15 of 30). No read-only or scoped keys. Access follows the user's role (3 of 20). Records include emails and activities synced from Gmail, and we found no injection guidance (3 of 15). No API audit log found (0 of 15). Vulnerability reports go to security@copper.com and the security page cites outside penetration tests. No certification named, the trust centre at trust.copper.com returned 403, no security.txt (404), and the page still lists the Privacy Shield programme, which was struck down in 2020 (6 of 20).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-security):

- 0 to 30, the credential model. 30 for OAuth 2.1 with scopes, or scoped and revocable keys with rotation. 20 for plain revocable API keys. 10 for one all-powerful key. 10 off when a secret can travel in a URL query string as a documented option.
- 0 to 20, read-only or least-privilege modes, and confirmation or approval for destructive actions.
- 0 to 15, prompt-injection posture where the tool returns untrusted content (documented mitigations or guidance). A tool that returns no untrusted content gets 10.
- 0 to 15, audit logs or per-call visibility for the operator.
- 0 to 20, a security programme. security.txt or a disclosure policy, a bug bounty, SOC 2 or ISO 27001, advisories handled in public.

Models are read for retention, whether API data trains models (and whether that's off by default), zero-retention options and certifications. Frameworks for telemetry defaults, approval hooks, guardrails and sandboxing.

## 2. Agent ergonomics, 40 out of 100, up to 9.8 more on the total

Why it scored 40: No MCP server. Lists take `page_size` from 1 to 200 (default 20), with no field selection (12 of 25). Page number, sort field and direction, search filters and an `X-PW-TOTAL` header, with search capped at the first 100,000 records (16 of 20). Error responses aren't documented beyond the 429 (5 of 20). No idempotency keys or upserts found (3 of 20). Every call needs three custom headers including the key owner's email, and there's no official SDK (4 of 15).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-ergonomics):

- 0 to 25, context cost. For MCP, the number and size of the tool definitions (25 for ten or fewer compact tools, 15 for 11 to 30, 5 for more than 30, plus up to 10 back for toolsets, dynamic loading or read-only subsets). For APIs, whether responses can be sized (field selection, limits, summaries).
- 20, pagination, filtering and output-size controls.
- 20, actionable, documented error responses, codes and messages an agent can recover from.
- 20, idempotency or safe retries, and for MCP the `readOnlyHint` and `destructiveHint` annotations.
- 15, sensible defaults, few required parameters, and official SDKs in at least two languages.

Models are read for tool use, structured output, prompt caching, context length, batch and SDKs. Frameworks for how much code and how many defaults a tool-calling agent with MCP needs.

## 3. Payments & pricing, 30 out of 100, up to 8.8 more on the total

Why it scored 30: No x402, MPP or L402 (0). Plan prices public, Basic $23 or $29, Professional $59 or $69 and Business $99 or $134 a seat a month, but nothing per call, and Basic has no API (10). Free trial, and the pricing page says 'no credit card required' (20). A person signs up in a browser and generates the key (0).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-payments):

The published rubric, also on the [x402 page](https://www.anchorterminal.com/x402/).

- 40, a machine payment protocol (x402, MPP or L402) on the tool's own endpoints. 10 to 30 when it covers only some endpoints or only goes through a third party, and the note says which.
- 20, per-call or per-unit pricing published without a login. 10 for public plan-only pricing, 0 for "contact sales" or prices behind a login.
- 20, a free tier or trial that doesn't need a card.
- 20, autonomous onboarding, meaning an agent can get access without a person signing up in a browser (keyless use, x402, a programmatic key API).

Payment platforms and agent wallets rarely charge for their own API over a machine protocol, so the first line has steps for them, and the highest one that applies counts. 40 when x402, MPP or L402 runs on all their own endpoints, 30 when it runs on part of their own API, 25 when their merchants can accept one, 20 for running a facilitator, 15 for paying as a buyer, and 0 when the only protocol is their own. Merchant acceptance sits above a facilitator because the platform's own customers can charge agents through it, while a facilitator settles for sellers who wire up the protocol themselves. The counter-argument (a facilitator does more for the protocol as a whole) has a point. Each note says which step applied.

Open-source software you run yourself is scored on its hosted or paid option if it has one. A free, self-hosted package with nothing to buy gets 20, 20 and 20 for the last three lines, and 0 to 40 for the first only if it ships a payment protocol.

## 4. Schema & documentation, 48 out of 100, up to 8.5 more on the total

Why it scored 48: No OpenAPI spec. A Postman collection and environment are the only machine-readable contract (10 of 25). No llms.txt or Markdown docs found (0). Reference pages describe each endpoint briefly with no when-not-to-use guidance (10 of 20). Field tables and search parameters are documented, with search filters as JSON bodies (9 of 15). Request and response examples, but no error code reference (7 of 15). Dated changelog and a single v1 path. Only three entries in 2026 (12 of 15).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-schema):

APIs and MCP servers.

- 25, a machine-readable contract (a public OpenAPI file or similar; for MCP, typed JSON Schema inputs on every tool).
- 10, llms.txt or Markdown docs served for agents.
- 0 to 20, descriptions that say what a tool is for, when to use it and when not to, read from the tool definitions in the source or the API reference.
- 0 to 15, typed inputs with enums, constraints and required fields, and no free-form JSON blobs.
- 0 to 15, examples and documented error responses.
- 15, versioning and a public changelog.

Models are read from the API reference, the OpenAPI file, llms.txt, the structured-output and tool-use docs and the model cards. Frameworks from docs a model can follow, typed interfaces, examples and the API reference.

## 5. Maintenance & community, 21 out of 100, up to 6.9 more on the total

Why it scored 21: Last API change on 2 July 2026 (S3 upload token), 91 days before the run, and a documentation entry on 30 August 2026. We scored between the 90 and 180-day bands because the newer entry is docs only (15). One dated entry in the last 90 days (0). Public changelog with three entries in 2026 and a support centre. We didn't test support (6 of 15). No official SDK in any language (0). No packages to judge (0).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-maintenance):

- 0 to 30, time since the last release, or the last published model or API change for a closed service. 30 within 30 days, 20 within 90, 10 within 180, 0 older.
- 20, at least three releases or dated changelog entries in the last 90 days.
- 0 to 25, responsiveness. Issues and pull requests answered on GitHub (the open issues and how recent the replies are). For closed services, a public changelog and a support or community channel that answers, 0 to 15.
- 15, presence in the official MCP registry under a verified namespace (MCP servers), or current official SDKs (APIs and models).
- 10, package health, current dependencies and CI.

Models are read for deprecation notice periods and model churn rather than release counts.

## 6. Reliability, 79 out of 100, up to 4.2 more on the total

Why it scored 79: Status page at status.copper.com with 26 entries back to March 2025 (20). No incidents between 3 July and 1 October 2026. The last entry was an 8-hour planned maintenance window on 27 June 2026 that took web and mobile down, just outside the 90 days (30). Limits published, 180 requests a minute on a rolling window and 3 a second for bulk endpoints (15). 429 is named but the docs give no Retry-After, no backoff guidance and no safe-retry advice for writes (4 of 15). No SLA found (0). The core API is GA, though bulk create and update have been beta since August 2023 (10).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-reliability):

Hosted APIs, MCP servers, models and platforms.

- 20, a public status page with component history (Statuspage, Instatus, BetterStack or the vendor's own).
- 0 to 30, the incident record for the last 90 days on that page. 30 for a clean record or trivial incidents only, 20 for minor incidents only, 10 for one major outage (an hour or more of a core API down, or errors across the board), 0 for several. 5 when there's no history we could read, and the note says so.
- 15, rate limits documented with numbers.
- 15, documented 429 or overload handling (Retry-After, backoff guidance), and idempotency keys or safe-retry guidance where writes are involved.
- 10, an SLA published for any paid tier.
- 10, the surface agents use is generally available, not beta or preview.

Local packages, SDKs, frameworks and stdio MCP servers.

- 20, installs from an official package with supported runtimes stated.
- 25, a public CI and test suite, passing on the default branch.
- 0 to 25, open crash or regression issues relative to activity (25 for few and handled, 0 for many, old and unanswered).
- 15, semver discipline and breaking changes called out in a changelog.
- 15, version 1.0 or later, or declared stable.

Protocols are read from their reference implementations, the public facilitators or servers, spec stability and test vectors.

## 7. Transparency & trust, 74 out of 100, up to 2.3 more on the total

Made of editorial 58, provenance 90.

Why it scored 74: Closed service with terms and a privacy policy naming Copper CRM, Inc., San Francisco (15). The privacy policy (11 May 2026) keeps CRM data at least 30 days after termination and purges it within 180 days, hosts in the US only, transfers under the Data Privacy Framework and SCCs, and says Workspace API data isn't used to train AI models. The security page still cites Privacy Shield (22 of 30). The only deprecation notice we found is the 2021 move from prosperworks.com, with redirects until early 2022, and no policy (6 of 20). Subprocessor list linked from the privacy policy and US-only hosting stated (15 of 20).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-transparency):

- 0 to 30, source availability and licence clarity. 30 for open source under an OSI licence, 15 for closed with clear terms, 0 for unclear terms.
- 0 to 30, data handling and retention statements that agree with each other (privacy policy, DPA, retention periods, subprocessors).
- 0 to 20, a deprecation policy or notices with dates.
- 0 to 20, telemetry disclosed with an opt-out (local software), or subprocessors and data locations disclosed (hosted).

The other half of Transparency and trust is the provenance score, computed from checked facts (below). The category score is the mean of the two.

Provenance checks not met in full (half of this category, computed from checked facts):

- security.txt: not found (0 of 10)

## What we couldn't check

What we couldn't read counted as absent. Publishing it on a page a plain HTTP fetch can read (not only in a browser) lets the next check count it.

- unchecked: certifications and subprocessors in the trust centre, which returned 403
- unchecked: trial length, which the pricing page doesn't state
- Whether API keys can be revoked and whether OAuth apps get scopes, neither documented on the pages we read
- The 30 September listing tagged Copper card-required, but the pricing page says no card is needed. Patched

## Weaknesses

- No official MCP server, OpenAPI spec or llms.txt
- API keys carry the owner's full rights, and admins can see every user's key
- No documented error format, Retry-After or idempotency
- Basic plan has no API access, so the first plan with it costs $59 a seat a month yearly
- Three changelog entries in 2026, and bulk endpoints still beta since 2023

## What costs an agent a turn today

The notes we give agents before they call it. Each one is a workaround an agent shouldn't need.

- Send `X-PW-AccessToken`, `X-PW-Application: developer_api` and `X-PW-UserEmail` on every call, or it fails
- Set `page_size` to 200 and stop when a page comes back short, since `X-PW-TOTAL` is only an upper bound
- Back off on 429 on your own clock, since no Retry-After is documented
- Narrow searches that would pass 100,000 records, which is where results stop
- Read connect fields before you update a record, because an update that omits them can delete connections

## What the review panel asked for

- publish an OpenAPI file
- document error bodies
- scoped read-only keys
- an API audit log

## When it's done

Send what changed and where it's published as a dispute (https://www.anchorterminal.com/builders/#disputes, or `POST https://www.anchorterminal.com/api/v1/contact` with `"kind": "dispute"`). Disputes are answered in public, and the listing is checked again by the same checklist. Paying for an audit or a listing claim changes nothing here.