Overview

A knowledge base is a named set of documents your agent can search while it's on a call. Attach one to an agent and it can answer from your own content — policies, product details, hours, fees — instead of only what fits in its prompt.

Knowledge bases live under Automations → Agents → Knowledge Base, separate from any single agent. You build one once and attach it to as many agents as you like, and editing its content updates every agent using it. A knowledge base belongs to your organization, and only your organization's agents can search it.

How the agent uses it

When a knowledge base is attached, the agent gains a search tool and decides for itself when to reach for it — typically when a caller asks something its prompt doesn't cover. It searches, reads the passages that come back, and answers in its own words rather than reciting the document.

Two things follow from that:

• Matching is on meaning, not exact wording. A caller asking "how late are you open?" can match a document that only says "business hours." You don't have to anticipate every phrasing.
• New content isn't searchable instantly. Indexing runs in the background, so a document reads Pending for a short while before it becomes Indexed.

The agent also decides not to search, and won't read a weak match aloud just because one exists. If nothing relevant comes back, it falls back to its prompt or tells the caller it doesn't have that information.

Create a knowledge base

Add content

A new knowledge base is empty. To fill it, click Add Source at the top of the knowledge base's page and choose Upload Files, Write an FAQ, or Crawl a Website.

Upload files

Choose Upload Files, then drag files onto the drop area or click to browse. Tandem accepts .pdf, .docx, .txt, and .md files up to 20 MB each. You can add several at once; click Upload and they're sent one after another. A file with an unsupported format or over the size limit is refused with a message naming it, and a file that fails to upload stays in the dialog so you can try again.

The filename becomes the document's title, so a descriptive name is worth the few seconds — refund-policy-2026.pdf reads better in the list than scan001.pdf.

Write an FAQ

For facts that don't live in a file (a cutoff time, a fee, a one-line policy), choose Write an FAQ. Enter a Title (the question, as a caller would ask it) and an Answer, then click Add FAQ.

Typed FAQs are often the highest-value content in a knowledge base. They're short, unambiguous, and already phrased the way callers speak, which is exactly what retrieval matches best.

Crawl a website

Choose Crawl a Website, enter a Starting URL beginning with http:// or https://, and click Start Crawl. Tandem crawls pages at or below that URL, following the site's robots.txt, up to 100 pages and 3 links deep by default. To change either limit, open Advanced and set Max pages (1–500) or Max depth (1–5). The dialog states the limits that will apply before you start.

The site appears in the list as a Website, named by its path with the host underneath, and a status of Crawling, then Ready, Partial, or Failed. Hover or focus a Failed badge to see why and what to do next. Click its row, or View Pages on it, to open a panel with its limits and the pages it indexed. Click Re-crawl on the row to pick up changes to the site.

Find a source

Everything in the knowledge base (files, FAQs, and websites) is one list, newest change first, with a Type column saying which each row is. Type in the search box to match by name, or click Filters and pick one or more types. A long list is split into pages of 20.

Edit a typed FAQ

A typed FAQ can be changed in place. Click the FAQ's row, or the pencil icon on it. A panel opens beside the page with the current Title and Answer; change either and click Save. The FAQ shows Pending while it re-indexes, then Indexed, and the agent answers from the new text on its next call.

Only typed FAQs have the pencil. Replace a file by uploading the new version and deleting the old one, and refresh a web source with Re-crawl.

Let Tandem suggest the FAQs

Tandem also collects the questions people asked that this knowledge base couldn't answer, and recommends them as FAQs to write. Those recommendations live on the Coaching page, not here, because they cover every knowledge base at once.

Attach it to an agent

A knowledge base does nothing until an agent points at it.

Retrieval settings

Two fields on the Knowledge card control how much each search returns. Both are optional — leave them empty to use the defaults, which suit most knowledge bases.

Max results — how many passages a search returns. Accepts 1–20, default 4. Raise it when a correct answer depends on details spread across several documents. Lower it when the agent drifts into loosely related material.

Minimum score — how closely a passage must match before it counts. Accepts 0–1, default 0.4. Raise it when the agent answers with content that's on-topic but not on-question. Lower it when you know the answer is in there but the agent says it can't find one.

Changing the agent's knowledge base resets Minimum score to the default, unless the same save sets a different value. The editor clears the field when you pick another knowledge base, and shows Minimum score reset to the new knowledge base's default. when a save resets it. To keep the same value on the new knowledge base, set it again after that save.

Document status

Every document in the list carries a status:

The list refreshes itself every few seconds while anything is Pending or a website is Crawling, so a row usually flips to Indexed or Ready without you doing anything.

A Failed document has no retry — delete it and add it again. If it fails a second time, the reason generally points at the file itself (an unreadable PDF, a document with no extractable text) rather than at something you can configure.

Limits and defaults

Tandem enforces these; the file limits are enforced on upload, so an oversized or unsupported file is rejected rather than silently ignored.

Writing content agents can use

Tandem enforces none of this.

• Answer one question per FAQ. A single FAQ covering shipping, returns, and refunds matches all three questions weakly. Three FAQs each match strongly.
• Use the words callers use. Title an FAQ "How do I get a refund?" rather than "Reimbursement Remediation Procedure." Retrieval matches meaning, but it matches familiar phrasing best — and the agent reads your wording back to the caller.
• Keep answers self-contained. The agent may retrieve one passage without its neighbors, so "as described above" or "see the table on page 4" gives it nothing to work with. Repeat the fact instead of pointing at it.
• Spell out abbreviations at least once. Write "annual percentage rate (APR)" so both forms can match.
• Prefer prose to layout. Dense tables, multi-column PDFs, and slide decks often extract as jumbled text. If a fact matters, state it in a sentence somewhere.
• Say what's true, not what's marketed. The agent will read a hedge or a slogan aloud verbatim, which sounds evasive on a call.
• Include the "we don't do that" answers. Documenting what you don't offer stops the agent from improvising an optimistic guess.

Structuring your knowledge base

• Split by subject, not by department. Callers ask about billing, not about which team owns billing. Group content the way a question arrives.
• Prefer several focused documents over one large one. A 200-page handbook splits its matches across many loosely related passages; ten short documents each match cleanly.
• Keep one authoritative answer per fact. Two documents giving different hours means the agent may retrieve either. Update in place rather than adding a second version.
• Use separate knowledge bases when audiences differ. Content a sales agent should read aloud is rarely the same content a support agent needs. Because an agent attaches exactly one knowledge base, splitting them is how you scope what each agent can say.
• Re-upload to replace, don't accumulate. Delete the superseded document when a policy changes, so retired policies can't surface on a call.
• Review after real calls. Reviewing real calls is still the quickest way to find a gap, but you no longer have to listen for one yourself. See Answer a suggested FAQ above.

Delete a knowledge base or document

Delete a document from the list on the knowledge base's page. It stops being searchable, and any agent using that knowledge base loses access to it on the next call.

Deleting a whole knowledge base is blocked while any agent still has it attached — the error names the agents that are holding it, so you can't silently break a live agent. Detach it on each agent's Knowledge card (set the dropdown to None), then delete it.

If some of its documents can't be deleted, the knowledge base is kept and the error says how many failed, for example Could not delete 2 of 40 documents; retry to finish removing this knowledge base. Delete it again to finish.

Troubleshooting

The agent says it doesn't know something that's in the knowledge base. Check the document's status is Indexed rather than Pending or Failed. If it's indexed, the phrasing is the usual culprit: add an FAQ that asks the question the way the caller did. Failing that, lower Minimum score slightly.

The agent answers with the wrong part of a document. A loosely related passage cleared the threshold and outranked the right one. Raise Minimum score, or split the document so each part covers a single subject.

The agent gives stale information. For a typed FAQ, edit it (see Edit a typed FAQ) rather than adding a second one. For a file, the old document is probably still there alongside the new one. Delete the superseded version — both remain searchable until you do.

The agent never uses the knowledge base at all. Confirm a knowledge base is selected on the agent's Knowledge card and that the change was saved. An agent with None selected has no search tool.

A document keeps failing. Open the file and confirm it contains selectable text. Image-only PDFs, empty files, and password-protected documents can't be indexed.

Next steps