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Migration visualization showing code, map, plan and diff

Understand the problem before you commit to a solution.

Ask a question. Get back a spreadsheet, not an essay.

Describe the change you're considering: "upgrade our auth system," "deprecate the billing API," "standardize error handling."

Tern reads your entire codebase and gives you back a structured inventory of everything involved.

Not a summary. Not "approximately 200 files." The actual files, classified by what kind of change they need.

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Upgrade our authentication system0 results

FilePatternOwner

src/auth/login.ts:42direct-call@auth-team

src/auth/signup.ts:18direct-call@auth-team

src/middleware/jwt.ts:7wrapper@platform

src/api/users.ts:134direct-call@users

lib/auth-helper.ts:22wrapper@platform

src/billing/verify.ts:89direct-call@billing

tests/auth.test.ts:15test-mock@auth-team

src/admin/auth.ts:56custom@admin

src/api/oauth.ts:201wrapper@auth-team

tests/billing.test.ts:44test-mock@billing

src/auth/token.ts:73direct-call@auth-team

src/services/notif.ts:31wrapper@platform

235 more

The complexity is in the patterns, not the count.

247 files isn't 247 identical changes. Tern classifies what's in your codebase: which call sites follow the standard pattern, which use custom wrappers, which are test mocks that need deletion instead of rewriting.

Filter by team, by pattern, by complexity. See the real shape of the work before you write a single line of code.

Organize itstacks

Upgrade our authentication system247 results

FilePatternOwner

▸Direct bcrypt calls134 sites

▾Wrapped auth helpers62 sites

src/middleware/jwt.ts:7wrapper@platform

lib/auth-helper.ts:22wrapper@platform

src/api/oauth.ts:201wrapper@auth-team

src/services/notif.ts:31wrapper@platform

▸Custom implementations8 sites

▸Test mocks43 sites

Different patterns, different prompts. Run them all.

The direct calls get one approach. The wrapped helpers get another. The custom implementations get reviewed by a human.

Run each prompt against its group, see what passed and what needs attention. You're not babysitting one AI session through hundreds of changes; you're orchestrating targeted fixes across patterns you already understand.

Ship itgraph_1

Upgrade our authentication system

FilePatternStatus

▾Direct bcrypt calls134 sites

src/auth/login.ts:42direct-callPending

[init] Loading direct-call migration...

Reading src/auth/login.ts:42

- const hash = bcrypt.hashSync(pwd, 10)

+ const hash = await argon2.hash(pwd)

Validation passed ✓

src/auth/signup.ts:18direct-callPending

src/api/users.ts:134direct-callPending

src/billing/verify.ts:89direct-callPending

src/auth/token.ts:73direct-callPending

▸Wrapped auth helpers62 sites

▸Custom implementations8 sites

▸Test mocks43 sites

Ask a question. Get back a spreadsheet, not an essay.

See itsearch

Upgrade our authentication system0 results

FilePatternOwner

src/auth/login.ts:42direct-call@auth-team

src/auth/signup.ts:18direct-call@auth-team

src/middleware/jwt.ts:7wrapper@platform

src/api/users.ts:134direct-call@users

lib/auth-helper.ts:22wrapper@platform

src/billing/verify.ts:89direct-call@billing

tests/auth.test.ts:15test-mock@auth-team

src/admin/auth.ts:56custom@admin

src/api/oauth.ts:201wrapper@auth-team

tests/billing.test.ts:44test-mock@billing

src/auth/token.ts:73direct-call@auth-team

src/services/notif.ts:31wrapper@platform

235 more

Upgrade our authentication system247 results

FilePatternOwner

▸Direct bcrypt calls134 sites

▾Wrapped auth helpers62 sites

src/middleware/jwt.ts:7wrapper@platform

lib/auth-helper.ts:22wrapper@platform

src/api/oauth.ts:201wrapper@auth-team

src/services/notif.ts:31wrapper@platform

▸Custom implementations8 sites

▸Test mocks43 sites

Upgrade our authentication system

FilePatternStatus

▾Direct bcrypt calls134 sites

src/auth/login.ts:42direct-callPending

[init] Loading direct-call migration...

Reading src/auth/login.ts:42

- const hash = bcrypt.hashSync(pwd, 10)

+ const hash = await argon2.hash(pwd)

Validation passed ✓

src/auth/signup.ts:18direct-callPending

src/api/users.ts:134direct-callPending

src/billing/verify.ts:89direct-callPending

src/auth/token.ts:73direct-callPending

▸Wrapped auth helpers62 sites

▸Custom implementations8 sites

▸Test mocks43 sites

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Arup Chakrabarti
Senior Director of Engineering, PagerDuty

Write the right code.

Understand the problem before you commit to a solution.

Ask a question. Get back a spreadsheet, not an essay.

The complexity is in the patterns, not the count.

Different patterns, different prompts. Run them all.

Ask a question. Get back a spreadsheet, not an essay.

Built for every ambitious change.

Upgrading React, Django, Rails?

Teams that see the work before they start it.

See what's in your codebase.